Keywords
gestational weight gain - patient navigation - postpartum weight retention
Nearly 50% of pregnant women are estimated to exceed recommendations for gestational
weight gain (GWG) goals and up to 75% of women weigh more than their prepregnancy
weight at 1 year postpartum.[1]
[2] Postpartum weight retention, or the failure to lose weight gained during pregnancy,
increases the risk for adverse outcomes in future pregnancies, such as stillbirth
and large for gestational age infants.[3] Such pregnancy weight changes can also dramatically influence a woman's long-term
health by increasing her risk for developing comorbidities, such as hypertension and
diabetes.[4]
During pregnancy, many women are motivated to change their health behaviors to have
a healthy pregnancy.[5]
[6] After delivery, a “natural period of redefinition” also occurs as a result of physiological,
social, and psychological changes.[7] Therefore, the postpartum period is also recognized as a window of opportunity for
health behavior change including weight management, but women face many challenges
with new roles and responsibilities as mothers with unpredictable schedules, thereby
making it difficult to prioritize their own health. Of note, the prevalence of overweight
and obesity was the highest among minority nonpregnant women in 2015 to 2016 (54.8%
for non-Hispanic blacks and 50.6% for Hispanics compared with 38.0% for non-Hispanic
whites) and associations between postpartum weight retention among non-Hispanic black
and low-income women have been reported.[1]
[8] Given the important long-term health implications of postpartum weight retention
and the potential for increased patient engagement in this early postpartum period,[9] interventions during these times are needed, especially for low-income and minority
women.
Patient navigation is the use of trained personnel to mitigate barriers and promote
health care access and engagement.[10] Navigation has been suggested as one mechanism to improve health care utilization
after birth. Patient navigators have a well-established role in oncology; however,
the concept of patient navigation in the prenatal and postpartum periods is more novel.
Furthermore, patient navigators may be a potential resource for weight management
interventions, given their frequent patient interactions that involve counseling,
resource provisions, and assistance with self-care, yet the concept has also not been
studied in pregnancy and postpartum-related weight management interventions. The objective
of this study was to evaluate postpartum weight retention at 6 weeks and up to 12 months
among women who participated in a postpartum patient navigation program designed to
improve uptake of postpartum care in a population of low-income, largely minority
women. Given the successes of this program related to postpartum health care utilization
and frequency of contraception uptake, depression screening, and vaccination,[11] we sought to investigate whether the positive changes in health care utilization
from navigation also carried over to other health behaviors, such as weight management.
Consequently, we hypothesized that women in the navigated cohort would have less-postpartum
weight retention at the 6 week and any subsequent follow-up visits compared with the
historical-control group.
Materials and Methods
The Navigating New Motherhood (NNM) program was adapted from a well-studied cancer
navigation model to the postpartum period for women receiving prenatal care at the
Northwestern Memorial Hospital obstetrics and gynecology practice that primarily provides
care for low-income women receiving publicly funded prenatal care.[11] The methods for the NNM program, as well as the comparison of outcomes to a historical-control
group have been previously published.[11] Briefly, the inclusion criteria were delivery in the second trimester or later at
the intervention site, > 18 years, English speaking, and HIV negative. The patient
navigator received extensive training with respect to postpartum care logistical and
supportive needs via in-person meetings with nurses, medical assistants, and physicians.
The navigator also worked with the social worker and lactation consultant and ultimately
integrated herself into the clinic environment. The navigator did not receive nutrition
or exercise-specific training or training specifically on weight-management navigation.
The navigator approached eligible participants in their third trimester of pregnancy
in the outpatient office or shortly after delivery in the hospital from 2015 to 2016.
After obtaining consent and performing intake surveys, the navigator scheduled the
participants' 6 week postpartum visit and any other recommended visits and sent scheduled
reminders 1 week after delivery, 1 week before the appointment, and 1 day before the
appointment. The navigator additionally provided social and logistical support to
postpartum women as needed, connected patients with health care providers, and provided
linkage to local resources. Brief written and verbal counseling about the benefits
of breastfeeding and contraception were provided during the inpatient visit as well.
During the 6 weeks' postpartum visit, the navigator met with each participant, ensured
that all needs were met, and coordinated future appointments. If participants did
not return for the visit, the navigator contacted them weekly up to 12 weeks postpartum.
The majority of the participants communicated with the navigator via text messages
with a minimum of three contact points with the navigator, but most women had three
to eight episodes of contact, as previously described.[12]
In this secondary analysis, participants were eligible for inclusion if height and
weight values prior to pregnancy, at delivery, and within 12 months of delivery were
available for abstraction from the electronic medical record. Gestational weight gain,
defined as the difference between the self-reported prepregnancy weight and the weight
at delivery, was compared between groups as a categorical variable (inadequate, adequate,
and excessive; weight gain vs. loss) according to the 2009 National Academy of Sciences
guidelines (28–40 pounds for body mass index [BMI] < 18.5 kg/m2, 25–35 pounds for BMI: 18.5–24.9 kg/m2, 15–25 pounds for BMI: 25.0–29.9 kg/m2, and 11–20 pounds for BMI ≥ 30 kg/m2).[4] All weight data were abstracted from the electronic medical record used for clinical
care.
The primary outcome was postpartum weight retention at the postpartum visit, analyzed
as a difference from the self-reported prepregnancy weight to the weight at the postpartum
visit. Additionally, this primary outcome was categorized as postpartum weight retention > 0 kg
(any weight retention) and > 5 kg over prepregnancy weight. Participants typically
returned to the clinic for a postpartum visit at approximately 6 weeks; however, for
this study we included any outpatient weight measurement that occurred between 4 and
12 weeks postpartum for the primary outcome, whether it occurred during a visit for
postpartum or other care (e.g., primary care, nurse visit, or other specialty care).
The secondary outcome was any weight measure up to 12 months postpartum noted in the
electronic medical record of this site (i.e., primary care, subsequent obstetric-gynecologic
care, or any other specialty care). This 12 month weight outcome was analyzed both
as a continuous variable and categorically, as for the primary outcome. Women who
were identified in the electronic medical record to have become pregnant again before
the final endpoint at 12 months after delivery were censored.
Maternal demographics (age, race, ethnicity, and marital status) and clinical characteristics
(nulliparity, number of prenatal visits, and gestational age at delivery) including
gestational weight gain (inadequate, adequate, and excessive) between the navigated
and historical-control participants were compared with Mann–Whitney tests, Fisher's
exact tests, and Chi-square tests as appropriate. Similarly, the primary (postpartum
weight retention at 4–12 weeks) and secondary (postpartum weight retention at 12 weeks–12 months)
outcomes were compared with Mann–Whitney tests and Chi-square tests as appropriate.
A p-value < 0.05 was considered statistically significant. An a priori power calculation
was not performed as the sample size was constrained by the original NNM study cohort.
The study was approved by the institutional review board (IRB) of Northwestern University.
All navigated participants signed written informed consent prior to participation.
The analysis was completed with STATA Statistical software program.
Results
From the original cohort of 218 navigated participants and 256 historical controls,
311 total women were eligible for inclusion for this analysis based on having height
and weight data (prepregnancy, at delivery, any postpartum visit) available. Of the
311 eligible women, 152 participated in the navigation program and 159 were historical
controls. The majority of patients were non-Hispanic black or Hispanic, and approximately
one-third were nulliparous. All women received Medicaid-funded prenatal care. There
were no differences in age, race and ethnicity, prepregnancy BMI, nulliparity, and
timing of initiation of prenatal care (p-value > 0.05 for all comparisons). Women in the navigation program had fewer numbers
of prenatal care visits (p-value = 0.003; [Table 1]).
Table 1
Maternal demographic and clinical characteristics for navigating new motherhood and
historical control
|
Variable (mean ± SD or n %)
|
Navigated (n = 152)
|
Historical control (n = 159)
|
p-Value
|
|
Age at delivery (y)
|
28.9 ± 4.9
|
29.4 ± 5.8
|
0.39
|
|
Hispanic
|
51 (30.8)
|
49 (33.6)
|
0.61
|
|
Race
|
|
|
0.55
|
|
White
|
68 (44.7)
|
61 (38.4)
|
|
Black
|
75 (49.3)
|
87 (54.7)
|
|
Asian
|
8 (5.3)
|
8 (5.0)
|
|
Other
|
1 (0.7)
|
3 (1.9)
|
|
Mean prepregnancy BMI (kg/m2)
|
29.8 ± 8.0
|
28.6 ± 7.5
|
0.22
|
|
Underweight
|
7 (4.6)
|
7 (4.4)
|
0.45
|
|
Normal
|
44 (28.9)
|
50 (31.4)
|
|
Overweight
|
31 (20.4)
|
42 (26.4)
|
|
Obese
|
70 (46.1)
|
60 (37.7)
|
|
Married
|
50 (32.9)
|
49 (30.8)
|
0.04
|
|
Nullipara
|
49 (32.2)
|
49 (30.8)
|
0.79
|
|
Total number of prenatal care visits
|
9.2 ± 3.3
|
10.3 ± 3.1
|
0.003
|
|
1st trimester care (≤ 13 wk)
|
74 (48.7)
|
93 (58.5)
|
0.08
|
|
Smoking
|
|
|
0.14
|
|
Current
|
9 (5.9)
|
7 (4.4)
|
|
Prior
|
28 (18.4)
|
19 (11.9)
|
|
Never
|
113 (74.3)
|
133 (83.6)
|
|
Missing
|
2 (1.3)
|
0
|
|
Antepartum depression (PHQ9 ≥ 9)
|
|
|
0.29
|
|
Yes
|
25 (16.4)
|
19 (12.0)
|
|
No
|
120 (79.0)
|
136 (85.5)
|
|
Missing
|
7 (4.6)
|
4 (2.5)
|
|
Diabetes (prepregnancy and gestational)
|
25 (16.4)
|
30 (18.9)
|
0.58
|
|
Antenatal nutrition consult[a]
|
31 (20.4)
|
29 (18.2)
|
0.52
|
Abbreviations: BMI, body mass index; PHQ9, patient health questionnaire-9; SD, standard
deviation.
Note: bold values indicate statistical significance.
a
n = 1 missing.
There were no differences in gestational weight gain classification according to guidelines
(20.4 vs. 25.2% inadequate, 22.4 vs. 27.7% adequate, 57.2 vs. 47.2% excessive; p-value > 0.05) between navigated and nonnavigated groups. Similarly, there were no
differences in obstetrical outcomes between navigated and nonnavigated groups, although
women in the navigated cohort were more likely to have neonates who were admitted
to the neonatal intensive care unit ([Table 2]). Postpartum weight was measured at a median of 6.3 weeks (interquartile range [IQR]:
6.0–7.1) and 24.4 weeks (IQR: 15.6–40.4) for the 4 to 12 weeks and up to 12 months
postpartum weight values, respectively.
Table 2
Antenatal and delivery outcomes for navigating new motherhood and historical control
|
Variable (mean ± SD or n %)
|
Navigated (n = 152)
|
Historical control (n = 159)
|
p-Value
|
|
Mean gestational weight gain (kg)
|
13.4 ± 7.2
|
12.7 ± 6.9
|
0.44
|
|
Inadequate gestational weight gain
|
31 (20.4)
|
40 (25.2)
|
0.21
|
|
Adequate gestational weight gain
|
34 (22.4)
|
44 (27.7)
|
|
Excessive gestational weight gain
|
87 (57.2)
|
75 (47.2)
|
|
Gestational hypertension or preeclampsia
|
18 (11.8)
|
12 (7.6)
|
0.20
|
|
Mean gestational age at delivery (wk)
|
38.6 ± 2.0
|
38.3 ± 2.6
|
0.12
|
|
Preterm delivery (< 37 wk)
|
19 (12.5)
|
24 (15.1)
|
0.51
|
|
Vaginal delivery
|
101 (66.5)
|
103 (64.8)
|
0.76
|
|
Postpartum hemorrhage[a]
|
8 (5.3)
|
11 (6.9)
|
0.52
|
|
Postpartum readmission
|
3 (2.0)
|
3 (1.9)
|
0.96
|
|
Birthweight (g)
|
3198 ± 549
|
3130 ± 649
|
0.35
|
|
NICU admission[b]
|
27 (17.8)
|
13 (8.2)
|
0.02
|
|
Postpartum visit[c]
|
150 (98.7)
|
153 (96.2)
|
0.17
|
|
Breastfeeding at postpartum visit[d]
|
76 (50.0)
|
85 (56.7)
|
0.14
|
|
Depression at postpartum visit[e]
|
3 (1.9)
|
11 (7.2)
|
0.02
|
Abbreviations: NICU, neonatal intensive care unit; SD, standard deviation.
Note: bold values indicate statistical significance.
a Postpartum hemorrhage was defined as > 500 cc for a vaginal delivery or > 1,000 cc
for a cesarean delivery.
b
n = 2 missing.
c Postpartum visit defined as a visit specifically for postpartum care as opposed to
primary or other specialty care.
d
n = 3 missing.
e
n = 33 missing.
The primary outcome, postpartum weight retention at 4 to 12 weeks' postpartum, did
not differ based on navigation status ([Table 3]). Neither mean postpartum weight retention (4.0 ± 6.7 kg for navigated vs. 2.7 ± 6.3 kg
for nonnavigated, p-value = 0.11) nor postpartum weight retention > 5 kg (42.4% for navigated vs. 34.7%
for nonnavigated, p-value = 0.15) differed between groups ([Table 3]). Findings also did not differ for postpartum weight retention > 0 kg.
Table 3
Postpartum weight outcomes for navigating new motherhood and historical control
|
Variable (mean ± SD or n %)
|
Navigated
|
Historical control
|
p-Value
|
|
At 4 to 12 weeks of postpartum
|
n = 144
|
N = 145
|
|
|
Mean weight (kg)
|
82.7 ± 21.7
|
78.2 ± 20.3
|
0.06
|
|
Mean PPWR (kg)
|
4.0 ± 6.7
|
2.7 ± 6.3
|
0.11
|
|
PPWR > 5 kg
|
61 (42.4)
|
50 (34.7)
|
0.18
|
|
PPWR > 0 kg
|
109 (75.7)
|
94 (65.2)
|
0.05
|
|
At 12 weeks, up to 12 months of postpartum
|
n = 50
|
n = 57
|
|
|
Mean weight (kg)
|
85.4 ± 26.3
|
81.5 ± 23.5
|
0.38
|
|
Mean PPWR (kg)
|
4.5 ± 7.1
|
5.0 ± 7.5
|
0.59
|
|
PPWR > 5 kg
|
22 (44.0)
|
30 (52.6)
|
0.37
|
|
PPWR > 0 kg
|
39 (78.0)
|
45 (78.9)
|
0.90
|
Abbreviation: PPWR, postpartum weight retention; SD, standard deviation.
Similarly, at up to 12 months postpartum, mean postpartum weight retention (4.5 ± 7.1 kg
for navigated vs. 5.0 ± 7.5 kg for nonnavigated, p-value = 0.59) and postpartum weight retention > 5 kg (44.0% for navigated vs. 52.6%
for nonnavigated, p-value = 0.55) did not differ between groups ([Table 3]). Findings also did not differ for postpartum weight retention > 0 kg.
Discussion
Although patient navigation has been demonstrated to improve multiple health services
outcomes, health outcomes, and patient-reported outcomes in oncology and is a promising
intervention to improve postpartum women's health care utilization, in this study
of predominantly low-income minority women, participation in postpartum patient navigation
was not associated with postpartum weight retention at 4 to 12 weeks. Similarly, in
the subgroup of women who had subsequent weights available at this site up to 12 months
postpartum, postpartum weight retention also did not differ between women who received
intensive postpartum patient navigation services versus those from the historical
control group.
Prevention of postpartum weight retention is essential for promotion of long-term
health.[3] Mean postpartum weight retention typically ranges from 0.5 to 4 kg and a value > 5 kg
is considered elevated.[13]
[14] Of significant interest, we noted that 48% of all participants had > 5 kg of postpartum
weight retention at 12 months postpartum compared with only 38% at 4 to 12 weeks'
postpartum in our study, suggesting that future evaluations and interventions for
postpartum weight retention will need to target a time period beyond the first 12
postpartum weeks. Our rates of postpartum weight retention > 5 kg at 12 months were
also significantly higher than other estimates (20%).[14]
[15] However, Endres et al reported that 47.4% of women who participated in a national
five-site prospective cohort study retained more than 10 pounds at 1 year postpartum.[1] Our findings may be partially explained by our high-risk population including low-income
minority women (32.2% Hispanic and 52.1% non-Hispanic black), women with prepregnancy
obesity (42%), and greater than 50% of women with excessive gestational weight gain,
all of which have been associated with excessive postpartum weight retention.
In light of the current and prior studies, new ways to approach weight management
in postpartum women are needed to improve the health of women and their families.
Over the last decade, multiple studies have supported the role of patient navigators,
especially as it relates to cancer prevention through survivorship.[16]
[17]
[18]
[19]
[20] In general, these programs have primarily assisted medically underserved patients
to overcome barriers to care including financial, logistical, system, cultural, and
personal factors that contribute to delay or failure to obtain treatment. For these
reasons, patient navigation may be a mechanism to improve outcomes for women in this
postpartum transition period. However, the data from this analysis suggest this particular
navigation intervention may require adaptation to improve postpartum weight outcomes.
Our study is timely given the recent focus on redesigning and optimizing postpartum
care or the “fourth trimester” for our patients.[21] The components of postpartum care encompass several domains such as mood, infant
care, contraception, and health maintenance. The American College of Obstetricians
and Gynecologists also recommends that providers counsel postpartum women with “actionable
guidance regarding resumption of physical activity and attainment of healthy weight.”
Successful components of lifestyle interventions that target postpartum weight retention
include frequent contact via text message or phone calls, face-to-face interactions,
or interval contact via web application.[22] Highly effective components of weight management interventions, in general, include
calorie and physical activity goals, self-monitoring, cognitive behavioral therapy,
and frequent provider–patient contact.[23] To our knowledge, none of the published postpartum weight retention trials used
a patient navigator to deliver the intervention content. We identified one protocol
for a home-based childhood obesity intervention scheduled to be delivered by patient
navigators.[24] In this 16-session, 25-hour program, patient navigators will offer hands-on opportunities
for skill building and provide detailed education and counseling to families by offering
sessions about reading food labels, grocery store outings, and cooking demonstrations.
Programs such as this one could be adapted to the unique transition period experienced
by postpartum women, if demonstrated to be efficacious. These tasks are also well
suited for trained patient navigators, as demonstrated in our mixed-method analysis
of communication between navigators and participants.[12]
Limitations
We recognize several limitations to this study including its small sample size and
single site setting of English-speaking women. Thus, the findings may not be applicable
to all populations. We also had a wider time period (12 weeks–12 months postpartum)
for our secondary postpartum weight-retention outcome, but this was necessary due
to irregular contact with the health care system after the initial postpartum visit.
Only women who had prepregnancy weights or returned for care within 12 months of delivery
at this site could be included, thus also increasing the risk for bias as women without
weight measurements could not be studied. However, the number of women in the historical
control and navigated group was similar, suggesting that the missing weight data were
similar for both groups. Lastly, the NNM program was not designed to be a weight-focused
intervention. Navigator training did not specifically include education on nutrition,
diet, or weight loss but instead focused on appointment scheduling, psychological
support, communication with health providers, and the benefits of contraception and
breastfeeding. Further, only a subgroup of women were actively receiving care at this
site during the 12 weeks to up to 12 months of postpartum period; other women may
have not been receiving medical care or receiving care at other sites which may have
introduced ascertainment bias.
Conclusion
Although patient navigation is a promising intervention to improve women's health
care utilization, in this particular navigation program, participation in postpartum
patient navigation was not associated with postpartum weight retention in the early
postpartum period (up to 12 weeks) or first year postpartum. This study provides initial
information on the relationship between patient navigators and postpartum weight retention.
Future studies that evaluate patient navigators and postpartum weight retention can
focus on adaptations to patient navigation that incorporate weight management goals
for women whose health and lifestyles change rapidly in a very-short-time period.
Additional work may also specifically focus on providing services to women at greatest
risk of postpartum weight retention, such as low-income minority women and women with
obesity or other comorbidities.
