Key words
mode of delivery - early preterm birth - pregnancy - perinatal mortality - neonatal
morbidity
Background
In 2017, the neonatology and paediatric intensive care working groups of the Austrian
Society of Paediatric and Adolescent Medicine (ÖGKJ) and ethics in paediatric and
adolescent medicine of the ÖGKJ as well as the Institute for Ethics and Law in Medicine
of the University of Vienna (IERM) published a guideline on “Primary care of premature infants at the limit of viability” in the monthly journal Kinderheilkunde [Paediatrics] [1].
This “guideline” analyses – from a paediatric viewpoint – the legal, ethical, organisational
and prognostic aspects of early preterm infants born between 22 + 0 and 24 + 6 WOP
(weeks of pregnancy). In the “guideline”, recommendations on the mode of delivery
during these early weeks of pregnancy are made for the first time. A brief statement
based on selected publications summed up that a planned Caesarean section versus a
vaginal delivery in the collective of early premature infants led to a lower risk
of cerebral haemorrhage in the premature infants and should thus be preferred.
This unilateral recommendation on the mode of delivery – which was not agreed upon
with the OEGGG – particularly in the form of increased liability with implied legally
binding effect as a “guideline” should be rejected in the OEGGGʼs view, since it technically
relates to the core competence of another field, obstetrics, and is not technically
tenable. The “guideline” takes relevant medical aspects of obstetrics into account
and the international studies available are not given appropriate consideration. A
guideline report on the “Primary care of premature infants at the limit of viability” “guideline” [1] was not published.
The problematic statement to be discussed in the paediatric guideline reads as follows:
“The data available suggest that, in the case of an extremely preterm birth, a Caesarean
section performed by experienced obstetricians, even with a cephalic presentation,
offers an advantage with regard to mortality and morbidity of the child. It can also
be shown that premature births at the start or end of the day as well as on Sundays
and holidays and especially at night are associated with a poorer outcome than premature
births during core working hours. In the case of a premature birth at the limit of
viability which is very likely foreseeable, a ”planned“ Caesarean delivery therefore
appears to be an advantage for the child.”
Specialist representatives of the Austrian Society for Gynaecology and Obstetrics
were not consulted on this obstetric recommendation while it was being drafted. There
is no consensus with representatives of the Austrian Society for Perinatal Medicine;
disagreements were not published.
Following an extensive discussion and evaluation of the available literature, the
following compromise proposal was unanimously adopted as a binding replacement for
the previously published paragraph 6.4 of the paediatric “guideline” by the representatives
of the paediatric and gynaecological association:
“There are inherently very little randomized data on the optimal mode of delivery
at the limit of viability and the results of published studies are contradictory.
Individual studies appear to suggest an advantage regarding mortality and the rate
of cerebral haemorrhage through a Caesarean delivery, while others do not find any
difference. Ultimately, the optimal mode of delivery must be individually determined.”
Additional Information from the OEGGG with a Review of the Literature
When compared to other European countries, the rate of premature birth in Austria
− 7.7% [2] – is in the middle. In particular, extremely preterm infants prior to the end of
the 26th WOP are still at risk of morbidity and mortality associated with a premature
birth. The international data on this topic are heterogeneous and insufficient. There
are no detailed obstetrical and neonatal data on the mode of delivery for the gestational
age of 22 + 0 to 24 + 6 WOP discussed in the guideline.
The criticism of the representatives of the OEGGG relates to two points in particular:
-
The recommended mode of delivery in the case of early preterm infants and
-
The clinical procedure in the case of deliveries outside of core working hours.
Our statement of the OEGGG refers exclusively to preterm singleton births with a cephalic
presentation. Multiple births and births with a breech presentation are exempted below
due to the varying data and thus differing recommendations.
Method
The obstetrical recommendations of the published paediatric “guideline” were unanimously
rejected by the executive board of the OEGGG after taking note of them. Thus at the
request of the OEGGG, there was a specialist meeting on 23 May 2017 with representatives
of the three societies ÖGKJ, IERM and OEGGG with the objective of changing, within
the consensus of professional societies, the recommendation which pertains to the
mode of delivery with regard to early premature birth and which is problematic from
a legal standpoint and incorrect from a medical standpoint. Participants were: A.
Berger (Vienna), C. Dadak (Vienna), T. Fischer (Salzburg), U. Kiechl-Kohlendorfer
(Innsbruck), H. Kiss (Vienna), U. Lang (Graz), M. Mörtl (Klagenfurt), P. Reif (Graz),
H. Salzer (Tulln) and M. Wald (Salzburg). The recommendation presented by the authors
to the executive board of the ÖGGG was discussed twice in the executive board and
unanimously approved by the executive board of the ÖGGG on 14 March 2018 for submission
for publication.
To answer the questions (mode of delivery in early premature birth and influence of
the time of delivery on neonatal morbidity), a literature search was conducted in
PubMed (literature up to 03/2018 taken into account) and the literature relevant for
answering the question was considered.
Mode of Delivery in Early Preterm Birth
The currently valid AWMF guideline [3], which was created with the cooperation of neonatal intensive care physicians and
representatives of the German Society for Gynaecology and Obstetrics, as well as representatives
of the German Society for Perinatal Medicine, recognised the insufficient and, to
some extent, contradictory data on the mode of delivery in the case of preterm birth
and therefore words a recommendation in an open way: “The results of available studies on the mode of delivery are contradictory. Whether
a Caesarean delivery offers advantages in a specific case must be individually assessed,
taking the condition and the child into account”.
The valid Swiss recommendations which have not been revised since 2011 come to an
analogous conclusion [4]. A Swiss publication therefore does not recommend a general Caesarean section in
situations of early preterm birth unless it is proven that the rate of Caesarean sections,
which is proven to be increasing, also leads to a neurological benefit for the premature
infants. The Swiss guideline focuses in particular on early premature infants with
a cephalic presentation without any associated maternal or foetal risks in whom a
primary Caesarean section offers no advantage [4]. By contrast, the perinatal mortality in early preterm births is decreased through
Caesarean section in the case of a twin pregnancy or breech presentation. Children
with weight retardation would benefit from a Caesarean delivery up to 30 + 0 WOP.
The collective of pregnant women at risk of a very early preterm delivery is very
heterogeneous. Prenatal indications are pitted against maternal indications. Therapy-refractory
birth events (such as therapy-refractory contractions, amniotic sac prolapse, amniotic
infection syndrome, premature placental abruption) are pitted against iatrogenic pregnancy
terminations (such as particularly severe preeclampsia, partial placental abruption,
severe placental insufficiency). This clinical variability which leads to early preterm
delivery does not permit or permits only a limited retrospective neonatal analysis
of the morbidity associated with the birth. Premature infants susceptible to developing
cerebral haemorrhage are more frequently children with a concomitant neonatal infection
and frequently the result of the maternal infection. Experience shows that these children
are regularly delivered vaginally due to the mechanics of the birth or events occurring
in the short term. Preterm infants following severe placental insufficiency or maternal
preeclampsia are almost exclusively delivered via a primary Caesarean section since
medicinal cervical ripening is not possible for reasons of time or uterine contractions
are not tolerated by the generally growth-retarded foetuses. The bias of the heterogeneous
indications for delivery is, to date, a nearly unsolvable problem in answering the
question of the optimal mode of delivery in the case of early preterm birth. A Caesarean
delivery in the case of an advanced birth, for example, due to a amniotic sac prolapse
or therapy-refractory contractions, can have a negative effect on the individual neonatal
morbidity risk due to the severe and sometimes traumatic child development.
Prospective randomised studies are desirable. The only Cochrane analysis on this topic,
dating from 2013, identified only 4 studies which meet the strict Cochrane criteria
[5]. The authors of the Cochrane Review conclude that the data from the 122 cases analysed
are not sufficient to be able to derive recommendations on the mode of delivery. All
four studies were discontinued early due to recruitment difficulties. There were no
differences between the delivery groups (planned Caesarean section vs. planned vaginal
delivery) in terms of the important neonatal mortality and morbidity criteria (asphyxia,
perinatal death, hypoxic ischaemic encephalopathy, respiratory distress syndrome and
postnatal development). The rate of acute maternal complications was significantly
higher in the randomised Caesarean section group (7/122 events) versus the vaginal
delivery group (wound infections, deep leg vein thrombosis, toxic shock and sepsis).
Because of the difficult surrounding ethical circumstances in a very heterogeneous
clinical collective, other prospective studies are not expected or only expected to
a limited degree. The neonatal and maternal long-term consequences of unnecessary
Caesarean sections, where applicable, were inherently not reviewed in this setting,
however they are well known and described.
Three retrospective studies from 2010, 2013 and 2016 [6], [7], [8] conclude that early preterm infants would not (automatically) benefit from a Caesarean
section:
-
“In our all-corners cohort, replicative of everyday obstetric practice, caesarean
delivery did not improve neonatal outcomes in preterm infants”. (23 + 0 – 36 + 0 WOP) [6].
-
“In severely premature infants born after spontaneous onset of labour, the risk of
adverse perinatal outcome does not seem to depend upon the mode of delivery, whereas
the risk of maternal complications is significantly increased after caesarean section”. (25 + 0 – 32 + 6 WOP) [7].
-
“In the preterm cohort, cesarean delivery was not protective against poor outcomes
and in fact was associated with increased risk of respiratory distress and low Apgar
score compared with vaginal delivery”. (24 + 0 – 34 + 0 WOP) [8].
However, these retrospective studies in a clinically heterogeneous collective are
limited in their evidence and frequently arrive at contradictory results. Ghi et al.
[7] demonstrate an increased tendency to develop intraventricular haemorrhage (OR: 1.7)
in the group of children born vaginally versus children born via Caesarean section.
Antenatal administration of steroids was, however, significantly more rare in the
vaginal group, at 67.7%, versus a rate of 88.0% in the Caesarean section group. Werner
et al. [8] did not find any difference in the case of cerebral haemorrhage, however, a difference
in the case of respiratory distress syndromes to the disadvantage of the Caesarean
section group (39.2 vs. 25.6%; OR 1.74). Small numbers of cases, very heterogeneous
antenatal treatments to encourage lung development, heterogeneous indications for
delivery and the mixing of the analysis of early and less early preterm births permit
only limited conclusions regarding the mode of delivery on neonatal morbidity and
mortality.
In a comprehensive review, Berger et al. [9] conducted a morbidity and mortality analysis of preterm infants depending on the
mode of delivery. Studies which show a reduction in neonatal mortality in the case
of early preterm birth [10], [11] are facing studies which do not show any difference [12], [13], [14], [15]. However, these studies investigate in part collectives with paediatric birth weights
up to 1500 g and not children with a gestational age of 22 + 0 to 24 + 6 WOP in an
isolated manner.
These studies are also only of limited importance for answering the present question,
since they primarily investigated neonatal mortality and the preterm infants came
from collectives which are clinically very different.
In a current American study from 2017 [16], a large preterm birth collective was likewise retrospectively analysed. However,
the study design is carefully selected, since in this study, the collectives “primary
Caesarean section” vs. “planned vaginal delivery” were investigated and thus realistically
reflect the hospital collectives. The secondary Caesarean sections were also included
in the group of planned vaginal deliveries. In the collective of planned vaginal deliveries,
no increased rate of neonatal cerebral haemorrhage (IVH grade 3 or 4) was detected.
Overall, the children of the “vaginal delivery group” even tended to have a better
outcome.
In the opinion of the representatives of the Austrian Society of Gynaecology and Obstetrics,
the optimal mode of delivery in the case of early preterm birth must be determined
depending on the overall foetal and maternal situation. In more than two thirds of
cases (68.1%), a primary or secondary Caesarean delivery was performed in 2016 in
Austria in the case of early preterm delivery (23 + 0 – 25 + 6 WOP, only live births).
This Caesarean section rate is stable. Over a nine-year period (2008 – 2016) the Caesarean
section rate in the collective of early preterm births was 66.8% on average. In the
nine-year average, 33.3% of the early preterm births (live births) were still delivered
vaginally (2016: 31.9%) ([Tables 1] and [2]) [17].
Table 1 Delivery methods (vaginal delivery vs. Caesarean section) in birth year 2016 in Austria
(only live births; 17).
|
WOP
|
Type of delivery
|
|
Vag. delivery
|
Caesarean section
|
|
Up to 22 + 6
|
65 (100.0%)
|
|
|
23 + 0 to 25 + 6
|
45 (31.9%)
|
96 (68.1%)
|
|
26 + 0 to 28 + 6
|
42 (18.2%)
|
189 (81.8%)
|
|
29 + 0 and above
|
60 186 (70.7%)
|
24 925 (29.3%)
|
|
Total
|
60 338 (70.5%)
|
25 210 (29.5%)
|
Table 2 Delivery methods (vaginal delivery vs. Caesarean section on average) in birth years
2008 – 2016 in Austria (only live births; 17).
|
WOP
|
Type of delivery
|
|
Vag. delivery
|
Caesarean section
|
|
Up to 22 + 6
|
389 (98.2%)
|
7 (1.8%)
|
|
23 + 0 to 25 + 6
|
358 (33.2%)
|
720 (66.8%)
|
|
26 + 0 to 28 + 6
|
316 (15.5%)
|
1 722 (84.5%)
|
|
29 + 0 and above
|
496 440 (71.4%)
|
198 895 (28.6%)
|
|
Total
|
497 503 (71.2%)
|
201 344 (28.8%)
|
Clinical experience shows that, in the case of associated maternal complications such
as severe preeclampsia and eclampsia, which frequently occur in combination with severe
placental insufficiency, there is often no leeway with regard to time or the clinical
situation for a vaginal delivery. The collective of potential vaginal deliveries in
the case of early preterm delivery is seen above all in the case of therapy-refractory
contractions and/or an amniotic sac prolapse. There is a consensus among obstetricians
that a quick vaginal delivery with a cephalic presentation versus Caesarean delivery
may sometimes be more gentle in these cases. Mothers in this situation and, consequently,
their children are affected by concomitant vaginal infections far more frequently.
In particular, foetal infections associated with the early preterm delivery worsen
the neonatal prognosis, especially the risk of intraventricular haemorrhage, and thus
in this collective, neonatal morbidity associated with the infection but independent
of the mode of delivery can be expected. The higher rate of over 30% vaginal deliveries
at an early gestational age between 23 + 0 to 25 + 6 WOP and the consecutive decrease
in vaginal deliveries to approximately 18% at a later gestational age between 26 + 0
to 28 + 6 WOP [17] reflects, in our opinion, the clinical situation of predominantly therapy-refractory
contractions at a very low gestational age and the need for indicated pregnancy terminations
due to placental insufficiency and maternal indications at a higher gestational age
([Tab. 1] and [2]). Subsequently (> 29 + 0 WOP) the rate of vaginal deliveries increases in Austria
in the case of preterm birth to 70.7%.
Influence of the Time of Delivery on Neonatal Morbidity
The “guideline” of the paediatric societies cites publications [18], [19], [20] which are intended to show a “worse outcome” of premature infants born outside of
core working hours. The times of an unfavourable outcome are defined as the start
and end of the day, Sundays and holidays and all nights. This would mean that, out
of 168 weekly hours, a lower-quality provision of healthcare is encountered for at
least 128 hours in perinatal centres of the highest level. The guideline therefore
calls for a preventive and thus preferred Caesarean section delivery in the cases
in which a “preterm delivery is very likely foreseeable”. In the opinion of the representatives of the OEGGG, a provision of healthcare of
the highest quality should be continuously guaranteed in perinatal centres, independent
of the time and day of the week. Increased neonatal mortality for weekend working
hours cannot be proven [21], however, it can have influencing factors which are centre-dependent and thus in
need of correction in individual cases. The advice that a delivery is should be favoured
in the case of a “high likelihood of delivery” can be misleadingly interpreted and it leads to the avoidable risk of early iatrogenic
preterm birth. In borderline situations, in the case of very early preterm birth,
the delivery can be “brought forward” by hours in situations in which it is virtually
certain that birth is imminent, whereby in individual cases, an even better provision
of paediatric healthcare could be guaranteed. The persons responsible for the Cochrane
analysis created for this purpose phrase the concerns of the OEGGG regarding this
topic analogously and unambiguously: “There is therefore, a real possibility that a policy of planned caesarean section
may increase the number of babies born preterm”.
Conclusions and Outcome for Practice
The discussion about the debated paediatric “guideline” and the present statement
from the OEGGG show that there is a need for an interdisciplinary guideline for the
diagnosis, prediction, prevention, treatment and neonatal primary care in the case
of preterm birth. The publication of the AWMF-S3 guideline “Caesarean section” is
still expected this year. The representatives of the OEGGG do not find it helpful
when statements from outside the field which have an apparently medically and legally
binding nature on a suggestive “guideline level” regarding the clinical approach are
made in our field. This statement from the OEGGG is intended to facilitate critical
reflection on the obstetrical approach and ensure forensic certainty for our colleagues
in obstetrics.
