Key words
pregnancy - lifestyle - preconception - nutrition - physical activity
Introduction
The first 1000 days post conception are regarded as a sensitive window of time that
can define the childʼs health and in which the risk of later non-transmissible diseases
can be modified [1]. The importance of a healthy lifestyle with a balanced diet and exercise in this
phase of life is an important building block for the prevention of these diseases
and is underlined by, amongst others, the national health goal “Before and after birth”
of 2017 [2].
In Germany, about a third of women of childbearing age are overweight or obese [5]. Obesity reduces the likelihood of conception [6] and is associated, amongst others, with a higher risk of pregnancy and birth complications,
birth defects, premature births and miscarriages, a high infant birth weight and later
obesity of the child [6], [7]. In 2014/15 gestational diabetes was diagnosed in 13% of pregnant women during a
screening programme [8]. About 11% of mothers of 0- to 6-year-old children reported in the German Health
Interview and Examination Survey for Children and Adolescents (KiGGS) that they had
smoked during pregnancy [11]. It is estimated that about 0.2 – 8 out of 1000 neonates in Germany are born annually
with fetal alcohol syndrome. Far more children are affected by a fetal alcohol spectrum
disorder [12].
A healthy lifestyle prevents risks of pregnancy complications and helps maintain the
health of mother and child. In this phase of life in particular expectant parents[
1
] are often highly motivated to optimise their lifestyle and are receptive to appropriate
recommendations. Women and couples wishing to have children are less aware that their
lifestyle affects fertility, the course of the pregnancy and also the childʼs later
health.
The recommendations of the Healthy Start – Young Family Network (Netzwerk Gesund ins
Leben) are intended to help contribute to a health-promoting lifestyle and thus to
promote the health of mothers and children and prevent long-term overweight and its
associated diseases. In 2012 the Germany-wide Practical Recommendations for Nutrition
in Pregnancy of the Healthy Start – Young Family Network were first published [13]. The updated version presented here has been extended to include recommendations
covering the period before pregnancy and around the time of conception.
They are intended to provide gynaecologists, midwives, paediatricians and members
of other health professions with a basis for counselling a healthy lifestyle.
Healthy Start – Young Family is a network of institutions, learned societies and associations
that are concerned with young families. The aim is to provide parents with uniform
messages about nutrition and exercise so that they and their children live healthy
lives and grow up healthy.
The Healthy Start – Young Family Network is part of the IN FORM initiative and is
accommodated in the Federal Centre for Nutrition (BZfE), an institution that comes
within the sphere of responsibility of the Federal Ministry of Food and Agriculture
(BMEL).
Methods
For the update of the recommendations on nutrition in pregnancy [13] and the extension to include recommendations for women wishing to have children,
in 2017 the recommendations of national and international learned organisations and
institutions were searched for statements on the diet, exercise, lifestyle and health
of pregnant women and those wishing to have children and examined for their topicality.
In addition, literature searches were undertaken in PubMed, Cochrane Library and Google
Scholar[
2
] and meta-analyses, systematic reviews, guidelines and relevant publications published
between 2012 and mid-2017 were assessed by the members of the scientific council (cf.
list of authors). In addition, aspects of lifestyle before conception, physical activity
before and during pregnancy and weight recommendations for pregnancy were discussed
in working groups with other acknowledged experts and practitioners (see page 1274)
from the appropriate specialist disciplines. On this basis, the present recommendations
were formulated by consensus by the scientific council. A more wide-ranging systematic
literature search and evidence assessment was not undertaken because of the lack of
financial resources for this. The key statements formulated correspond to the evidence
level of an expert recommendation with particular regard to aggregated sources of
evidence. Their wording is based on that used in guidelines. Thus, “must” refers to
a strong recommendation (German “soll”), “should” to a moderately strong recommendation
(German “sollte”) and “can” to an open recommendation (German “kann”). The respective
“Bases of the recommendations” sections make it apparent how these were derived.
These practical recommendations have been reviewed and endorsed by the boards of the
following associations: Professional Association of German Gynaecologists (BVF), the
German Association of Midwives (DHV), the Professional Association of Paediatricians
(BVKJ); and the following scientific societies: German Society of Pediatrics and Adolescent
Medicine), German Society of Obstetrics and Gynaecology (DGGG), German Society for
Sport Medicine and Prevention (DGSP), German Society of Midwifery Science (DGHWi)
and German Society for Nutrition (DGE).
General Recommendation
Recommendation
-
Professional groups who care for women of childbearing age, particularly women with
a concrete wish to have children, as well as pregnant women must encourage and counsel
them to follow a balanced diet, physical activity and a healthy lifestyle.
Women/couples wishing to have children and expectant parents are frequently unaware
that they can exert a long-term effect not only on their own health but also on that
of their children through their nutrition and their lifestyle [3], [4], [14]. The lifestyle of a future family is influenced by both partners. Professionals
must inform women of childbearing age and their partners, women/couples wishing to
have children and expectant parents of the long-term importance of a healthy lifestyle
and know that a third of pregnancies are unplanned or are not planned for that particular
time [15].
Body Weight Before Conception and Weight Gain in Pregnancy
Body Weight Before Conception and Weight Gain in Pregnancy
Recommendations
-
Even before pregnancy, the optimal adjustment of body weight to a normal weight is
desirable.
-
An appropriate weight gain in pregnancy is between about 10 and 16 kg for women of
normal weight.
-
In the case of overweight and obese women, a lower weight gain in pregnancy is desirable.
-
In underweight women, it should be ensured that there is sufficient weight gain during
pregnancy.
Bases of the recommendations
Meta-analyses and systematic reviews underline the fact that both women who are overweight
and those who are underweight before conception have a higher health risk than those
with normal weight [16], [17], [18], [19], [20]. The recommendation that women should adjust their body weight before pregnancy
to that approaching a more normal weight is consistent with international [4] and national recommendations [21], [22].
A weight gain of between 10 and 16 kg is associated with a low risk of fetal and maternal
complications in women of normal weight [25], [26], [27]. The risk increases with a higher weight gain [28], particularly if the woman is overweight or obese when embarking on pregnancy [29]. Therefore a weight gain of about 10 kg is regarded as sufficient for overweight
and obese women. A general recommendation for a minimum weight gain in underweight
women cannot be given. Overall, the evidence is too inconsistent to define exact upper
and lower limits for a desirable weight gain in pregnancy according to preconceptual
body mass index (BMI). Internationally there is no consensus on the recommendations
for weight gain in pregnancy, particularly for overweight and obese women [30], [31].
Background information
In Germany, 30% of 18- to 29-year-old women, 38% of 30- to 39-year-olds and 46% of
40- to 49-year-olds are overweight or obese (DEGS1) [5]. Only up to about 4.5% of women in these age groups are underweight [5]. Overweight/obesity before pregnancy and also high weight gain in pregnancy (frequently
defined as weight gain above the recommendation of the Institute of Medicine [IOM],
see below) were associated in observational studies with an increased occurrence of
gestational diabetes, hypertension and birth complications [16], [18], [19], fetal macrosomia [20], large for gestational age (LGA) and later overweight of the child and associated
complications [19], [32], [33], [34]. Maternal overweight and obesity at the beginning of pregnancy are associated with
a shorter life expectancy of the child [35]. Underweight in pregnancy was associated with more frequent premature births, miscarriages
and low birth weight [17], [36], [37], [38]. It is therefore desirable for both overweight and underweight women to approximate
to normal weight before pregnancy. Weight gain in pregnancy is characterised by high
variability [23], [24] and has a lower predictive significance than BMI at the beginning of pregnancy.
For women who are obese, even a weight loss of 5 to 10% of the starting weight before
pregnancy can have a significantly positive effect on health and also increase the
chance of becoming pregnant [22]. The therapeutic measures (if necessary including bariatric surgery) that may be
considered for weight reduction in severely obese women in preparation for a pregnancy
must be decided individually in a medical consultation on the basis of current scientific
findings and guidelines [39], [40], [41].
Pronounced weight gain normally does not occur until the second trimester of pregnancy.
Pregnant women should be informed of the causes of weight gain and the risks of obesity
or excessive weight gain. Weight loss diets in pregnancy are not recommended because
of safety concerns.
The American Institute of Medicine (IOM) [27] recommends a different weight gain for pregnant women according to BMI at the beginning
of pregnancy [27]. These recommendations are based on epidemiological association studies in American
and Danish women. The recommendations have been adopted by some countries such as
Italy, Denmark and Switzerland, in some cases with slight adjustments. As the weight
ranges recommended by the IOM could not be confirmed in other international [42] and national epidemiological studies [24], [43] and could not be substantiated by the results of a few interventional studies on
a change of lifestyle in normal and overweight/obese women [44], [45], [46], [47], their use in everyday clinical practice is not recommended here and by other expert
groups [13], [22] (cf. also Suppl. Table S1).
The increased risk of later overweight in the child as a result of a high maternal
weight gain in pregnancy is also discussed, but the weight gain during pregnancy has
less effect on the risk of overweight and the childʼs health than the baseline weight
of the mother in particular [48], [49], [50].
Energy and Nutritional Requirements in Pregnancy
Energy and Nutritional Requirements in Pregnancy
Recommendations
-
Pregnant women should pay particular attention to the quality of their diet. Compared
to the energy requirement, the requirement for individual vitamins and minerals/trace
elements increases much more in pregnancy.
-
Energy requirements increase only slightly over the course of pregnancy. Pregnant
women should increase their energy intake only slightly (up to about 10%) and not
until the last few months of pregnancy.
Basis of the recommendations
The recommendations take account of the mathematically determined increase in energy
requirements, which is the basis of international and national reference values [4], [25], [51], [52], and the usually markedly reduced physical activity, particularly in the third trimester
[53].
Background information
A high-calorie diet can have a detrimental effect on the course of pregnancy and on
the childʼs health [54], [55], [56], [57]. Pregnant women often overestimate their actual increase in energy requirement.
Energy consumption increases in particular due to the energy requirement for tissue
formation and fetal growth. Purely mathematically, there is an additional energy requirement
of 76 530 kcal for a woman of normal weight and a weight gain in pregnancy of 12 kg
[58]. From this is derived the guideline value of the German Nutrition Society (DGE)
for an additional energy intake of 250 kg kcal/day in the second trimester and 500 kcal/day
in the third trimester with unchanged physical activity [52]. However, physical activity usually declines considerably [59], [60], so that in many women an increased energy intake is not required.
The requirement for a series of vitamins and minerals increases in pregnancy much
more than the energy requirement, mainly from the 4th month onwards [61]. For the nutrients folate and iodine a markedly increased intake is recommended
from the beginning or even before pregnancy [52]. Recommended additional intake of various nutrients are indicated in [Fig. 1]. With the exception of folate and iodine [52] (see section Supplements), the increased requirement for vitamins and minerals can
usually be covered by a suitable choice of food. The consumption of supplements cannot
replace a balanced diet. During counselling the concept of “think for two but do not
eat for two (do not eat double portions)” should be emphasised and illustrated by
examples of foods with high nutrient densities (vegetables, fruit, wholegrain products,
dairy products, etc.).
Fig. 1 Reference nutrient values – Recommended additional intake in pregnancy according
to German Nutrition Society (DGE), expressed as a percentage of the reference value
[52].
Nutrition
Recommendations
-
The diet must be balanced and varied before and during pregnancy. It should be based
on the general recommendations for healthy adults.
-
In a balanced diet, the food groups should be weighted differently:
-
Both calorie-free beverages and plant-based foods (vegetables, fruit, pulses, wholegrain
products) should be consumed abundantly.
-
Animal-based foods (milk and dairy products, low-fat meat and low-fat meat products,
oily sea fish and eggs) should be eaten moderately.
-
Sweets, sugar-containing beverages and snacks as well as fats with a high proportion
of saturated fatty acids (in particular animal fats) and oils should be only consumed
sparingly. Plant oils (e.g. rapeseed and olive oil) should be preferred as sources
of fat.
Bases of the recommendations
International [4], [19] and national [52], [62] learned societies and institutions give recommendations for a balanced and varied
diet before and during pregnancy that are based on the general recommendations for
adults [52], [63]. The data are insufficient to allow special nutritional recommendations to be formulated,
e.g. for improving fertility [64]. There is no robust evidence for particular diets or for preferring certain macronutrients
(proteins, carbohydrates, fats) for weight loss or for the avoidance of excessive
weight gain in pregnancy [57], [65].
Background information
A balanced diet and regular physical activity before and during pregnancy not only
have a positive short-term effect on the course of pregnancy and the development of
the unborn child, but also have positive long-term effects on the health and well-being
of mother and child [1], [4], [66]. A systematic review showed that weight gain and the risk of pre-eclampsia can be
reduced by diet and lifestyle interventions in pregnancy (in normal-weight, overweight
and obese women), in addition to which a non-significant trend to reduction of gestational
diabetes, hypertension, premature births and intrauterine death was observed [67]. In an interventional study in overweight pregnant women with an increased risk
of gestational diabetes, appropriate weight gain and a lesser decline in physical
activity in early pregnancy was achieved through repeated healthy eating and physical
activity messages [68]. No reduction in gestational diabetes was obtained with other lifestyle interventions
in obese pregnant women [65]. Although the data are inconsistent, nutrition and exercise should be addressed
repeatedly when counselling pregnant women.
In a meta-analysis of 11 randomised interventional studies (1985 pregnant women, mean
BMI 21.5 – 32.4 kg/m2), a diet with a low glycaemic index was associated with lower blood glucose concentrations
in the women (fasting and 2 hours postprandially) and a lower risk of large for gestational
age (LGA) infants than a diet with a higher glycaemic index [69]. A systematic review of observational studies showed a lower risk of gestational
diabetes with a diet with a high intake of vegetables, fruit, wholegrain products,
nuts, pulses and fish; by contrast, a diet rich in fat, a large amount of red meat
and eggs was associated with a higher risk [9].
Because of the physiological changes and the growth of the uterus (the stomach and
intestine are compressed), smaller meals divided over the day can promote the well-being
of the expectant mother.
With a balanced diet, the food groups can be divided according to the recommended
frequencies and amounts of consumption into “abundant”, “moderate” and “sparing”.
Foods with a high nutrient density (high content of essential nutrients relative to
their energy content) are required for sufficient amounts of vitamins and minerals
to be absorbed despite the only slight increase in energy requirement. With the nutrients
folate and iodine, the increased requirement could theoretically be covered by a very
specific choice of food [70], although in practice this is rarely achieved (see section “Supplements”).
A guideline value for the daily amount of water for the general population and also
during pregnancy is about 1.5 L [52]. In hot environments or during heavy physical activity, a larger amount of water
is required.
The daily consumption of at least three portions of vegetables and two portions of
fruit is desirable [63]. Cereal products, particularly from wholegrain cereals, and potatoes are rich in
vitamins, minerals and fibre. Milk and dairy products, which provide protein, calcium
and iodine, are important components of a balanced diet. Fish is an important source
of vitamin B12, zinc and iron. A preference for certain types of meat is not necessary for an adequate
iron intake, but low-fat meat and meat products should be chosen specifically.
Through the weekly consumption of fish, particularly one portion of oily sea fish
(e.g. mackerel, herring or sardines), it is possible to achieve the additionally recommended
quantity of the long-chain omega-3 fatty acid docosahexaenoic acid (DHA) of at least
200 mg/day in pregnancy (for fish/DHA in relation to allergy prevention, see section
“Nutrition for the prevention of allergies in the child”). A high consumption of carnivorous
fish (e.g. tuna, swordfish), which are at the end of the maritime food chain and may
contain a high content of toxic substances, should be avoided for reasons of preventive
health care in pregnancy [52], [71]. The regular consumption of sea fish as well as iodised salt contributes to the
supply of iodine. However, salt should be used sparingly.
Vegetarian and Vegan Diet in Pregnancy
Vegetarian and Vegan Diet in Pregnancy
Recommendations
-
A balanced vegetarian diet with the consumption of milk, dairy products and eggs (ovo-lacto
vegetarianism) can in principle cover most nutrient needs even during pregnancy. Specific
counselling is recommended.
-
In the case of a purely plant-based (vegan) diet, the supply of critical nutrients
must be checked by a physician and individual nutritional counselling given. As well
as iodine and folic acid, additional micronutrient supplementation (particularly vitamin
B12) is required to prevent a nutrient deficiency and subsequent damage to the childʼs
development.
Bases of the recommendations
The study data on vegetarian and vegan diets in pregnancy is sparse and in some cases
contradictory [72]. The recommendations are therefore based on the general recommendations for an ovo-lacto
vegetarian diet with due regard to the “critical” nutrients in pregnancy [62], [73]. An undersupply of vitamin B12 occurring after many years of a vegan diet without supplementation can lead to severe
and long-lasting damage to the childʼs nervous system as well as haematological and
neurological problems for the mother during pregnancy [74], [75], [76].
Background information
Sufficient nutrient intake is possible in pregnancy with a balanced and consciously
designed ovo-lacto vegetarian diet, with the exception of the nutrients folic acid
and iodine (and in some cases DHA), which generally need to be supplemented during
pregnancy.
Milk and dairy products, eggs, pulses and cereal products usually provide sufficient
protein intake. The risk of insufficient iron intake is increased for ovo-lacto vegetarians
[77], [78]. Pulses, (wholegrain) cereal products and some types of vegetable contain reasonably
large quantities of iron, although less readily available than iron from meat and
fish. The concomitant consumption of vitamin C-rich foods (e.g. citrus fruits, peppers)
can improve iron intake. Depending on the medically determined iron status, iron may
be supplemented if necessary (see section “Supplements”). Critical nutrients for pregnant
women following a vegetarian diet for a long time even before they became pregnant
include vitamin B12, DHA and possibly zinc [74], [77], [79], [80].
With a purely plant-based (vegan) diet, intake of vitamin B12, DHA, zinc, protein, iron, calcium and iodine is critical. In particular, adequate
intake of vitamin B12 is not possible with a purely plant-based diet without nutritional supplements and
fortified foods. Vegans who wish to keep to their diet in pregnancy should undergo
qualified nutritional counselling as soon as they wish to have children in order to
eliminate any nutritional deficiencies before conception. Vegans should have their
intake of critical nutrients regularly checked medically during pregnancy as well,
so that they can take specific supplements and where necessary consume fortified foods
to cover their nutrient requirement [73].
Supplements
Folic acid supplement
Recommendations
-
In addition to a balanced diet, women planning a pregnancy must take 400 µg of folic
acid daily or equivalent doses of other folates in the form of a supplement.
-
Supplementation must begin at least four weeks before conception and continue until
the end of the first trimester of pregnancy.
-
Women who start folic acid supplementation less than 4 weeks before conception should
use higher-dosed products.
Bases of the recommendations
It has been found in numerous epidemiological studies and meta-analyses based on these
studies that periconceptual folic acid supplementation of 400 µg/day (alone or in
combination with other micronutrients) can reduce the risk of birth defects of the
nervous system (neural tube defects; NTD) (e.g. [81], [82], [83], [84], [85], [86]). In Germany and many other countries it has therefore been recommended since about
the middle of the 1990s that, in addition to a folate-rich diet, women who want to
or could become pregnant should take 400 µg of folic acid daily or equivalent doses
of other folates (calcium L-methylfolate or 5-methyltetrahydrofolic acid glucosamine)
in the form of supplements and continue the supplementation also in the first trimester
of pregnancy [87], [88], [89], [90]. In some countries the dose recommendation is somewhat higher, e.g. 500 µg daily
in Australia [91]. If intake begins only shortly before or even after conception, supplements of 800 µg
folic acid should be used [92], [93] in order to reach the red blood cell folate concentrations recommended by the WHO
more rapidly [94].
Background information
Folate is important for cell division and growth processes, amongst others. Consumption
of folate-rich plant nutrients such as greens, cabbages, pulses, wholegrain products,
tomatoes or oranges can contribute to the supply of folate. According to the German
National Nutrition Survey (NVS II), the median intake of folate equivalents in women
of reproductive age is between 153 and 185 µg/day [95] and thus markedly below the German, Austrian and Swiss reference values for nutrient
intake derived for adults (300 µg/day) and pregnant women (550 µg/day) [52]. In the German Health Interview and Examination Survey for Adults (DEGS1), serum
and red blood cell folate concentrations were for the first time measured representatively
for the adult population. The results of this study give rise to the conclusion that
85% of the population reaches the target folate values for non-pregnant women [96]. However, fewer than 5% of women of reproductive age reach the red blood cell folate
concentration of 400 ng/mL (906 nmol/L) recommended by the WHO for effective risk
reduction of neural tube defects [94], [96].
As closure of the neural tube normally occurs within 3 to 4 weeks of conception, folic
acid supplementation must be started prior even to conception for the greatest possible
risk reduction of neural tube defects. The time interval until the recommended folate
concentration is reached is dependent on the baseline concentration and the supplemented
dose: thus, with a daily intake of 400 µg of folic acid, 6 to 8 weeks are needed to
reach a red blood cell folate concentration of 906 nmol/L; with an intake of 800 µg/day,
however, only about 4 weeks are required [92], [93], [97]. A daily intake of 1000 µg folic acid/day is considered safe (tolerable upper intake
level) [98], [99].
Currently only a small proportion of women in Germany take a preventive folic acid
supplement. Admittedly almost 90% of women take a folic acid supplement in pregnancy
[100], but only about 10 to 34% begin at the recommended time and use a dose of at least
400 µg/day [101], [102], [103]. In Germany, dosage forms in different doses are available. If women take a multivitamin
product purely for NTD prevention, it should be ensured that this contains at least
400 µg of folic acid.
Iodine supplement
Bases of the recommendation
According to WHO criteria [104], Germany is an area with a mild to moderate iodine deficiency. The median iodine
intake in women of reproductive age (calculated from iodine excretion in the 24-hour
urine) according to the DEGS study was about 125 µg/day [105]. Thus, the median value did not reach either the reference intake for adult women
of 200 µg/day [52] or the higher recommended intake of the German Nutrition Society for pregnant women
of 230 µg/day [52]. A supplement with a dose of 100 to 150 µg daily appears sufficient to achieve the
recommended intake for pregnancy. The dose equates to the lower to middle end of the
range for iodine supplementation in pregnancy mentioned in the maternity guidelines
and regarded as safe (100 to 200 µg/day) [106]. It is comparable to the recommendations of international bodies [107], [108], [109].
Background information
Women wishing to have children should be counselled about the importance of iodine
even before pregnancy. Consideration should be given to an adequate iodine intake.
The use of iodised cooking salt and the regular consumption of milk, dairy products
and sea fish are worth recommending (see also section “Nutrition”). In terms of foodstuffs
(e.g. bread), products with iodised table salt should be chosen out of preference.
Women with thyroid disorders should be given medical advice and also avoid iodine
deficiency. In women with Hashimotoʼs thyroiditis, the required level of iodine intake
(through iodised salt, foods with added iodised salt, fish, etc.) is usually unproblematic.
In pregnancy, the iodine requirement increases due to the increased maternal production
of thyroid hormones and increased renal excretion, but also due to the requirement
for the unborn childʼs development (placental transfer). In total, an increased iodine
requirement of about 30 to 50 µg/day is assumed [52], [110]. Accordingly, the reference value derived by the German, Austrian and Swiss societies
for iodine intake increases from 200 µg to 230 µg/day [52]. Based on an adequate intake value of 150 µg/day for non-pregnant women, the EFSA
recommends an intake of 200 µg/day in pregnancy [110]. If products with 100 to 150 µg iodine are already being taken, additional iodine
supplements should not be taken.
A series of epidemiological studies indicate that even a moderate undersupply of iodine,
particularly in early pregnancy, or a deficiency of thyroid hormones (hypothyroxinaemia)
during this period can have an unfavourable effect on the childʼs cognitive and psychomotor
development [111], [112], [113], [114], [115], [116], [117]. The few studies in which the effects on pregnancy of iodine supplementation in
moderate iodine deficiency have been investigated [114], [116], [118], [119], [120] indicate that the mother also benefits from iodine supplementation and has a lower
risk of developing hypothyroidism after the birth.
The iodine content in sea algae, particularly in dried algae and seaweed products,
can vary considerably and in some cases be very high. Thus, even with small dietary
quantities of algae/products, as well as when taking several iodised nutritional supplements,
there may be an increased iodine intake [121], [122]. In addition, algae can be rich in arsenic and other contaminants [122]. The consumption of algae and algal products is therefore discouraged.
Other supplements
Recommendations
-
Iron supplements in addition to a balanced diet should only be taken after a medically
diagnosed deficiency.
-
Pregnant women who do not consume oily sea fish regularly are recommended to take
DHA supplements.
Bases of the recommendations
Iron supplementation in pregnancy improves maternal status and protects against anaemia;
however, as regards the benefit to the child of general supplementation of all pregnant
women, the data are inconclusive [123], [124], [125]. In addition, there is evidence that additional iron intake in well-supplied pregnant
women can increase the risk of premature births and low birth weight [126], [127]. Against this background, general prophylactic iron supplementation is not recommended
for pregnant women in Germany. This is consistent with recommendations of other European
countries (e.g. UK [128], France [129] and Ireland [130]. On the other hand, routine supplementation of iron in combination with folic acid
is recommended internationally by the WHO in pregnancy since in some developing countries
there is a considerable proportion of pregnant women who have iron deficiency anaemia
[4], [19], [131].
The omega-3 fatty acid docosahexaenoic acid (DHA) is found in particular in oily sea
fish. Pregnant women who abstain from these foods should take supplements with DHA
to achieve the recommended intake amount in the German, Austrian and Swiss reference
values of at least 200 mg DHA daily on average [52] or the additional intake recommended by the EFSA in pregnancy of 100 to 200 mg DHA,
in addition to the recommended intake for non-pregnant women of 250 mg DHA daily plus
eicosapentaenoic acid (EPA) [132], [133].
Background information
Iron deficiency in pregnancy increases the risk of premature birth and low birth weight
[126], [134], [135]. The iron requirement increases in pregnancy because more iron is required for the
fetus, placenta and the 20% increase in red blood cells in the expectant mother. Pregnant
women should therefore ensure a sufficient intake of iron-rich foodstuffs.
The reference value for iron intake in pregnancy in Germany of 30 mg/day is 100% higher
than that for non-pregnant women [52]. According to NVS II, women of childbearing age (18 to 49 years) consume a median
of 11 to 12 mg iron per day [95]. These data indicate that the generally recommended intake amount in the normal
diet is not reached. However, menstrual blood loss ceases [52] and intestinal iron absorption increases in pregnancy. Therefore, the EFSA, for
example [136], assumes an equally high dietary iron requirement for pregnant women as for non-pregnant
women. As well as determinations of Hb, the additional determination of serum ferritin
[137] in the context of antenatal care is useful in obtaining evidence of insufficient
or empty iron stores [106].
Vegetarians have a small intake of DHA and have a lower DHA status than women who
also consume fish, meat and eggs [138]. The alpha-linoleic acid (ALA) contained in some vegetable oils (e.g. rapeseed,
walnut, linseed oil), nuts and seeds (e.g. walnuts) can provide a contribution to
the supply of omega-3 fatty acid; however, endogenous synthesis of DHA from ALA is
low [138], [139], [140], [141], [142], [143], [144]. Women who do not (regularly) consume oily sea fish should therefore take DHA as
a supplement during pregnancy.
In randomised controlled trials, supplementation with fish oil or long-chain omega-3
fatty acids such as DHA resulted in a significant reduction in the risk for early
premature births up to 34 weeks of pregnancy [145], [146], [147]. DHA is important for the development of visual function and brain in the fetus
[148]. In some observational studies, the consumption of fish and the supply of long-chain
omega-3 fatty acids in pregnancy were associated with a more favourable childhood
development of cognitive and other abilities [149], [150], [151], [152], [153]. Other studies fail to confirm this [154], [155]. Data on the benefit of DHA supplements in pregnancy for the childʼs cognitive development
are inconsistent.
The vitamin D supplied to the expectant mother exerts an effect on fetal vitamin D
supply and infant bone mineralisation [156], [157], [158]. Vitamin D is formed in particular in the skin during exposure to sunlight. Thus,
a supply of vitamin D can be guaranteed by spending a regular amount of time outdoors.
For light skin types, it is sufficient in the summer months in our latitudes to expose
the unprotected face and arms to the sun for about 5 to 10 minutes daily in the midday
period. Sunburn should be avoided at all costs. In the absence of endogenous vitamin
D synthesis, i.e. in periods of low sunlight and with a predominantly indoor existence,
the German Nutrition Society recommends a vitamin D intake of 20 µg (800 IU) daily
for pregnant women (as for all other groups of people from infancy onwards) [52]. The average amount of vitamin D absorbed from the diet is only 2 to 4 µg daily
[95]. This is insufficient to achieve a sufficient intake with limited exposure to sunlight
and low endogenous vitamin D synthesis throughout the year. Pregnant women who rarely
spend time in the sun or extensively cover their skin or use sunscreen lotions on
exposure to the sun as well as women with dark skin types should therefore use a supplement
with vitamin D [52].
Protection against Food-Borne Illnesses During Pregnancy
Protection against Food-Borne Illnesses During Pregnancy
Recommendations
-
Pregnant women must avoid raw, animal-based foods. In addition, they should follow
the recommendations to avoid listeriosis and toxoplasmosis in the choice, storage
and preparation of foods.
-
Pregnant women must only eat eggs if the yolk and egg white are firm from being heated.
Bases of the recommendations
Recommendations on the choice, preparation and storage of foods are summarised in
the information sheet published in 2017 “Listeriosis and toxoplasmosis. Safe eating
during pregnancy” from the Federal Centre for Nutrition [161] (order no. 0346, www.ble-medienservice.de). They are based on data from zoonosis monitoring and other communications from the
Federal States on the presence of zoonosis pathogens in foodstuffs studied and study
results of food-related disease outbreaks, literature analyses and expert opinions
as well as from members of the Committee for Biological Hazards and Hygiene at the
Federal Institute for Risk Assessment. As salmonellosis can be harmful to mother and
child, eggs should be consumed only when cooked thoroughly.
Background information
The pathogens of listeriosis and toxoplasmosis can be transmitted to the placenta
and the unborn child during pregnancy and cause severe illnesses as well as premature
births and stillbirths [159], [160]. Each year about 20 to 40 cases of neonatal listeriosis and about 5 to 40 cases
of congenital toxoplasmosis in neonates [162], [163] are reported to the Robert Koch Institute (www.rki.de), but the reporting system only covers laboratory-confirmed cases. A national seroprevalence
study estimates there to be 345 cases of congenital toxoplasmosis annually in Germany
[164].
In the case of toxoplasmosis, the consumption of raw meat from pigs, lambs, sheep
and game as well as of meat that is not fully cooked (including in the form of raw
sausage meat such as salami or raw ham) is particularly problematical [160], [165], [166].
Raw meat products, smoked fish and soft cheeses (including those made from heat-treated
milk such as Gorgonzola) have a high risk of containing pathogenic listeria; raw milk
and derived products as well as vegetables and salads may also be affected [159], [167], [168], [169], [170]. Listeria can also be found in heated foods. It can also proliferate at refrigerator
temperatures as well as in products packaged under vacuum or in a controlled atmosphere.
Pregnant women should prepare their food as close as possible to the time of consumption
and consume it rapidly. In restaurants and cafeterias they should where possible consume
food that has been heated immediately prior to consumption. As well as choice of foods,
hygiene in storage and preparation plays an important role in protecting against food-borne
illnesses.
Exercise Before and During Pregnancy
Exercise Before and During Pregnancy
Recommendations
-
Women who are planning a pregnancy and pregnant women must follow the general exercise
recommendations for adults.
-
Women must also be physically active in everyday life during pregnancy and must limit
or regularly interrupt sedentary activities.
-
Pregnant women should be moderately physically active for at least 30 minutes at least
5 days a week and preferably daily. Moderately active means that conversation is still
possible during sporting activity (talk test).
-
Women who engage in sport can also be more intensively physically active in pregnancy.
Bases of the recommendations
The recommendations are based on recommendations by other learned societies and expert
groups such as the National Recommendations for Physical Activity and Physical Activity
Promotion [53], [171], [172], [173], [174], [175].
Meta-analyses and systematic reviews of randomised controlled interventional studies
as well as observational studies suggest that moderate physical activity during pregnancy
is not only safe for the pregnant woman and the child [176], [177], but also produces a variety of positive effects. Thus exercise/sport during pregnancy
is associated with a reduced risk of LGA [178], [179], premature birth [177], [180], [181], caesarean section [44], [176], [182], [183], gestational diabetes [10], [47], [176], [177], [178], [184], pregnancy-induced hypertension [176], [183], excessive weight gain [44], [178], [185], [186], incontinence [187], [188], back pain [189], [190] and improved psychosocial well-being [53]. Data findings focused exclusively on overweight and obese pregnant women are not
quite so extensive. In summary, in this respect a risk reduction has been demonstrated
for premature birth, gestational diabetes and excessive weight gain by the practice
of physical activity as part of a lifestyle intervention in pregnancy [44], [177].
Background information
The recommendations on the level of activity of 30 minutes of physical activity on
at least 5 days a week are documented by the improvement in cardiorespiratory and
muscular fitness and the prevention of noncommunicable diseases [191]. In terms of pregnancy-specific aspects, the evidence for certain levels and intensities
of activity is limited; generally, however, in a complication-free pregnancy the positive
effect of exercise on the course of the pregnancy and the health of mother and child
is undisputed [192].
For pregnant women, aerobic endurance activity is particularly recommended and should
be undertaken at moderate intensity [193] and in exercise units of at least 10 minutes. Moderate intensity means the exercise
is experienced as slightly strenuous and conversation is possible (talk test). Physical
activity in everyday life is also desirable, e.g. walking quickly or climbing steps.
The aim of 10 000 steps a day can serve as a guide for the level of daily activities
[194], [195], which should be supplemented by sporting activities. Types of sports that draw
upon large muscle groups are particularly suitable, including for beginners, and include
walking, Nordic walking, bicycling at moderate speed, swimming/aqua fitness, cross-country
skiing and low impact aerobic or pregnancy yoga. Women should not begin new types
of sports with unaccustomed sequences of movement in pregnancy. Types of sports that
are considered inappropriate are those with a high risk of falls and injury, e.g.
team, contact or fighting sports or scuba-diving [53]. Healthy pregnant women can be physically active at elevations of up to 2000 to
2500 m, particularly if they are accustomed to these elevations [196], [197]. Women who engage in sport can continue their previous sporting activity in a complication-free
pregnancy and train somewhat more intensively than beginners [171], [193], [198], [199].
Possible warning signs are vaginal bleeding, labour, loss of amniotic fluid, dyspnoea,
dizziness, headache, chest pain, muscular imbalance, calf pain and swelling [53]. Physical activity is contraindicated in haemodynamically relevant heart diseases,
restrictive lung disease, cervical insufficiency, premature labour, persistent bleeding
in the second and third trimester, placenta praevia after 26 weeks of pregnancy, ruptured
amniotic sac, pre-eclampsia, pregnancy-induced hypertension or severe anaemia [53].
In reality, the level of exercise frequently declines during pregnancy [53], [60]. Reported barriers are lack of time, lack of motivation and above all fears and
safety aspects [200]. Professionals should encourage pregnant women to arrange their everyday life and
leisure time so as to be active and to limit or regularly interrupt sedentary activities.
They should take the concerns and anxieties of pregnant women/expectant parents seriously
and inform them that exercise is desirable in a normal healthy pregnancy and safe
for mother and child.
Alcohol
Bases of the recommendation
On the basis of the available evidence it is not possible to define a safe and risk-free
amount of alcohol for the fetus or a time window in pregnancy when alcohol consumption
does not present a risk [204]. National and international learned societies [4], [52], [205] and the Federal Centre for Health Education (BZgA) therefore advise against drinking
alcohol during pregnancy. It is also recommended to refrain from alcohol during the
period of planning a pregnancy [3], [4], [206], [207].
Background information
Alcohol consumption during pregnancy can lead to birth defects, growth restriction,
damage to tissue and nerve cells as well as to an irreversible reduction in the childʼs
intelligence and can exert an effect on its behaviour (hyperactivity, impulsivity,
distraction, risky behaviour, infantilism and disorders of social maturity) [201], [202], [203]. Fetal alcohol syndrome (FAS) is the most common avoidable disability in neonates
with an estimated incidence of 0.2 – 8 in 1000 neonates [12]. Substantially more children are affected by a fetal alcohol spectrum disorder [12], [203]. The extent of the individual health risk to the child is difficult to predict and
is affected by maternal and fetal characteristics. Although large systematic studies
have demonstrated no negative long-term effect of mild to moderate alcohol consumption
[208], it is safest to avoid all alcohol consumption [209]. The recommendation “to avoid alcohol in pregnancy” could promote uncertainty or
feelings of guilt in women who consumed alcohol early in pregnancy before they were
aware of the pregnancy. For this reason, specialists should provide differentiated
and sensitive advice.
Smoking
Bases of the recommendations
The recommendation to change smoking habits even during the phase of wishing to have
a child and of not smoking in pregnancy meet the recommendations of the Fédération
Internationale de Gynécologie et dʼObstétrique (FIGO) [4], other national specialist organisations [62], [128] and the Federal Centre for Health Education [218].
Background information
Smoking has a negative effect on fertility [64] and can increase the risk for premature births and miscarriages, birth defects,
premature placental detachment and low birth weight, but also the later risk for obesity
and allergies in the child [210], [211], [212], [213], [214], [215], [216], [217]. In Germany, 26% of 18- to 25-year-old women and 34% of men of the same age smoke
[11]; in older age groups, the proportion is somewhat higher (30% of women, 35% of men)
[219]. Of the mothers of 0- to 6-year-old children questioned in the KiGGS study, 11%
had smoked in pregnancy. Pregnant women under 25 years of age at the time of their
childʼs birth or belonging to a low socioeconomic group had smoked twice as often
during pregnancy as older women or women with a high socioeconomic status [220].
All professional groups who counsel women/couples wishing to have a child, pregnant
women and expectant parents should discuss smoking and where necessary explicitly
and repeatedly address the persons they are counselling about their cigarette consumption
or their habits. They should motivate them to adopt weaning measures and point out
that the wish to have children and pregnancy are good opportunities to stop smoking.
To encourage smoking cessation, materials are also specifically available for pregnant
women and for disseminators as well as advice lines (www.rauchfrei-info.de).
Nicotine is frequently contained in e-cigarettes. Even for e-cigarettes without nicotine,
health concerns are raised [221]. Pregnant women are therefore recommended to avoid e-cigarettes.
Caffeinated Beverages During Pregnancy
Caffeinated Beverages During Pregnancy
Bases of the recommendation
The data are inadequate for assessing possible detrimental effects of caffeine on
the mother and child and for quantifying amounts of caffeine that do not present a
risk. A dose-dependent association between caffeine consumption in pregnancy and the
risk of fetal growth retardation and negative effects on birth weight has been observed
in studies [222], [223]. The EFSA gives a safe caffeine dose for the period of pregnancy of 200 mg/day [224].
Background information
Caffeine crosses the placenta rapidly but cannot be metabolised either by the fetus
or in the placenta [224]. The relationship between maternal caffeine intake and pregnancy duration, birth
weight, fetal growth retardation and small for gestational age (SGA) has been investigated
in studies. According to a current meta-analysis of case-control and observational
studies, there is a significantly increased risk of spontaneous abortion from 300 mg
caffeine daily and above [225]. Another meta-analysis shows a linear association between caffeine consumption and
miscarriage rate, although other possible confounding factors were not considered
[226]. A Cochrane meta-analysis was unable to draw any conclusions about the effectiveness
of abstention from caffeine on birth weight or other relevant endpoints because of
limited data [227].
Data on the mean caffeine content of beverages are shown in [Table 1]. Energy drinks must not contain more than 320 mg caffeine/litre [228] and those containing 150 mg caffeine per litre and over must be labelled “Increased
caffeine content. Not recommended for children and pregnant or breast-feeding women”
[229]. Further typical ingredients of energy drinks are glucuronolactone, taurine and
inositol, the interactions between which have not been fully established, as well
as large amounts of sugar. Pregnant women should therefore avoid energy drinks.
Table 1 Mean caffeine contents of drinks (according to EFSA 2015 [224] and BfR 2015 [230]).
|
200 ml filter coffee:
|
about 90 mg
|
|
60 ml espresso:
|
about 80 mg
|
|
200 ml black tea (1 cup):
|
about 45 mg
|
|
200 ml green tea (1 cup):
|
about 30 mg
|
|
250 ml cola drinks:
|
25 mg/330 ml (can about 35 mg)
|
|
250 ml energy drink (1 tin):
|
about 80 mg
|
|
200 ml cocoa drink:
|
8 to 35 mg
|
Medication Use in Pregnancy
Medication Use in Pregnancy
Basis of the recommendations
Medications, whether prescription-only or over-the-counter, may affect the child.
The overwhelming majority of medications have been insufficiently studied in terms
of risks in pregnancy. In the consumption and prescription of medications, the individual
risk to the mother from not receiving treatment must be weighed against the risks
to the unborn child.
Background information
Substance-specific recommendations can be given in the course of a medical consultation.
Where necessary, a dose adjustment or a switch of medication may be necessary even
before conception. Necessary treatment must not be stopped because of wrong assumptions
about harm to the unborn child.
Within the Pharmacovigilance Network of the Federal Institute for Drugs and Medical
Devices (BfArM), the course of pregnancies for which the network has provided advice
on medication use is documented and these data are evaluated jointly with similar
centres in other European countries (ENTIS European Network of Territorial Information
Services [https://www.entis-org.eu]). Information about the safety of medications in pregnancy and during breast-feeding
is available via the website www.embryotox.de.
Women with chronic diseases who are planning a pregnancy require special medical counselling.
Preparation for Breast-Feeding
Preparation for Breast-Feeding
Bases of the recommendation
A Cochrane review article comes to the conclusion that all forms of additional support
have a positive effect on the increased duration of breast-feeding and the duration
of exclusive breast-feeding [231]. The recommendation is consistent with recommendations on the promotion of breast-feeding
in Germany [239] and in other countries [249].
Background information
Measures to support breast-feeding exert a positive effect on the initiation and duration
of breast-feeding [231]. Since the motherʼs intention to breastfeed, an early latch and early initiation
of breast-feeding are very important for successful breast-feeding and insecurities
often lead to premature weaning [232], [233], [234], [235], [236], women and their partners should obtain breast-feeding counselling even during pregnancy.
A positive attitude on the part of the partner also has a positive effect on the initiation
and duration of breast-feeding [237], [238]. Professionals and trained lay people, personal (as opposed to telephone) support,
four to eight contacts and settings with high initial breast-feeding rates can promote
exclusive breast-feeding [241].
Although different forms of support in pregnancy and during the post partum period
show positive effects on the attitude to breast-feeding, it is not possible to provide
more specific details, e.g. in terms of measures or times [231], [240], [241], [242], [243], [244]. Counselling and support are more effective if they are offered not only for a short
time, but where possible over the whole of the pregnancy until after the childʼs birth
[245] and in an ambulatory as well as an inpatient setting [246].
Nutrition in Pregnancy for the Prevention of Allergies in the Child
Nutrition in Pregnancy for the Prevention of Allergies in the Child
Recommendations
-
Pregnant women must not exclude any foods from their diet to prevent allergies in
the child. The avoidance of certain foods during pregnancy is not beneficial for the
prevention of allergies in the child.
-
Pregnant women are recommended to consume oily fish regularly also with respect to
allergy prevention.
Basis of the recommendations
The recommendations are based on current data and the German guidelines for allergy
prevention of 2014 [247].
Background information
A low-allergen diet on the part of the mother during pregnancy does not lead to a
reduced allergy risk in the child [248], [249]. Dietary restrictions are therefore not meaningful and can also be associated with
the risk of insufficient nutrient intake. However, foods to which the woman herself
exhibits an allergic reaction should also be avoided in pregnancy.
There is evidence that the consumption of sea fish and the long-chain omega-3 fatty
acids that they contain during pregnancy and/or while breast-feeding has a protective
effect against the development of atopic diseases in the child [250], [251]. Randomised controlled trials have shown that the risk of asthma is halved in children
whose mothers had taken long-chain omega-3 fatty acids at doses greater than 2 g/day
as a supplement during pregnancy [252], [253].
The consumption of prebiotics and probiotics during pregnancy does not offer any sufficiently
proven benefits for allergy prevention in the child.
From the point of view of allergy prevention in the child as well, pregnant women
should avoid smoking and areas where there is or has been smoking. In families with
a medical history of allergies, the acquisition of cats should be avoided. Furthermore,
pregnant women should avoid high exposure to air pollutants and mould accumulation
in order to protect their health.
Oral and Dental Health
Bases of the recommendation
Untreated maternal periodontitis has been associated in studies with an increased
risk of premature birth and low birth weight [255], [256], [257], [258]). Mothers with untreated caries pass on caries-associated bacteria to their child
[259], thus increasing the risk of caries in the child [256], [260]. Appropriate oral hygiene and a healthy diet for teeth reduce the caries-associated
microflora. Dentist-supported caries prevention of the mother in pregnancy has the
potential to reduce the later degree of caries in the child [261], [262].
Background information
Regular appropriate oral hygiene is one of the general health care measures and is
recommended for all adults [254]. Altered defence reactions in the gingiva and hormonal changes in pregnancy (increased
oestrogen and progesterone levels) encourage the development of inflammation of the
gums (gingivitis), characterised by increased sensitivity and a tendency to bleeding
[263]. Existing periodontitis can be exacerbated [263]. Whether treatment of periodontitis reduces the risk of premature birth and low
birth weight cannot be answered with certainty due to contradictory study results
[257], [258], [264].
Recommended dental and oral hygiene includes brushing the teeth with fluorinated toothpaste
at least twice a day, carefully cleaning the gaps between the teeth with dental floss
or interdental brushes once a day [254], [265] and having the teeth cleaned professionally at the dentistʼs at individually defined
intervals. The frequency depends among other factors on the individual risk for caries
and periodontitis [266]. The German Society of Periodontology (DG PARO) recommends supporting oral hygiene
by professional teeth cleaning with oral hygiene instruction at the beginning and
end of pregnancy [263].
Where diseases of the teeth and gums are present, the dentist should be consulted
where possible even before the pregnancy. As well as preventive and diagnostic measures,
preservative treatments can usually also be performed during pregnancy (such as the
placement of fillings, fitting of individual crowns or treatment of periodontitis
[255], [267]. As a rule amalgam fillings should not be placed during pregnancy [268]. In specific indications, amalgam fillings can be removed and replaced by other
filling material.
Vaccinations
Basis of the recommendation
Vaccine-preventable diseases during pregnancy increase the risk to the womanʼs health,
can result in severe birth defects in the child and may be life-threatening for newborns.
The Standing Committee on Vaccination at the Robert Koch Institute (STIKO) gives recommendations
for women of childbearing age wishing to have a child, for women in pregnancy and
for further contacts in the infantʼs immediate environment [269].
Background information
Complete protection against measles, rubella, varicella (chickenpox) and pertussis
(whooping cough) is of particular importance in the family planning phase. The STIKO
recommends the appropriate vaccinations for women wishing to have children. While
dead vaccines (inactivated vaccines: killed pathogens or their constituents) can in
principle be administered even in pregnancy, live vaccines (such as those for measles,
mumps, rubella and varicella) are contraindicated for pregnant women. After each vaccination
with a live vaccine, reliable contraception must be recommended one month. However,
even if this period is not observed and even in the event of inadvertent vaccination
in early pregnancy, no fetal damage as a result of these vaccinations is known to
date [270].
Vaccinations not only protect the pregnant woman, who is more susceptible to infection
due to hormonal changes than outside of pregnancy, but also the unborn or newborn
child. Practically all viral infections in pregnancy are associated with an increased
risk of abortions, birth defects, premature births and complications of pregnancy.
In addition, pregnant women are themselves at increased risk, e.g. in the case of
measles, of developing severe pneumonia.
There is a particularly high risk of severe disease courses in influenza infections
in pregnancy. The STIKO has recommended vaccination against seasonal influenza for
all pregnant women since 2010 [271], which also protects the neonate in the first few weeks of life against serious
courses of diseases as a result of the maternal vaccine-induced antibodies, also known
as “nest protection” [272].
Conclusion
A balanced diet, regular exercise and a healthy lifestyle are particularly important
before and during pregnancy. The time before conception and the first 1000 days of
the childʼs life provide an opportunity to lay the foundations for the health of the
child, the expectant mother and the family. This potential for prevention should be
recognised and utilised on a broad basis. The revised recommendations presented here
provide uniform, practical and up-to-date knowledge-based recommendations for pregnancy
and also for women/couples wishing to have a child.
