The INTERGROWTH-21st gestational weight gain standard and interpregnancy weight increase: A population-based study of successive pregnancies

Should gestational weight gain charts exclude individuals with excess postpartum weight retention?

BACKGROUND

High gestational weight gain is associated with excess postpartum weight retention, yet excess postpartum weight retention is not an exclusion criterion for current gestational weight gain charts. We aimed to assess the impact of excluding individuals with high interpregnancy weight change (a proxy for excess postpartum weight retention) on gestational weight gain distributions.

METHODS

We included individuals with an index birth from 2008 to 2014 and a subsequent birth before 2019, in the population-based Stockholm-Gotland Perinatal Cohort. We estimated gestational weight gain (kg) at 25 and 37 weeks, using weight at first prenatal visit (<14 weeks) as the reference. We calculated high interpregnancy weight change (≥10 kg and ≥5 kg) using the difference between weight at the start of an index and subsequent pregnancy. We compared gestational weight gain distributions and percentiles (stratified by early-pregnancy body mass index) before and after excluding participants with high interpregnancy weight change.

RESULTS

Among 55,723 participants, 17% had ≥10 kg and 34% had ≥5 kg interpregnancy weight change. The third, tenth, 50th, 90th and 97th percentiles of gestational weight gain were similar (largely within 1 kg) before versus after excluding participants with high interpregnancy weight change, at both 25 and 37 weeks. For example, among normal weight participants at 37 weeks, the 50th and 97th percentiles were 14 kg and 23 kg including versus 13 kg and 23 kg excluding participants with ≥5 kg interpregnancy weight change.

CONCLUSIONS

Excluding individuals with excess postpartum weight retention from normative gestational weight gain charts may not meaningfully impact the charts' percentiles.

Gestational weight gain and adverse birth outcomes in South African women with HIV on antiretroviral therapy and without HIV: a prospective cohort study

INTRODUCTION

Outside of pregnancy, evidence shows that persons with HIV initiating or switching to dolutegravir (DTG)-based antiretroviral therapy (ART) experience greater weight gain compared to those on other ART classes. However, there are few data on the impact of DTG-based ART on gestational weight gain (GWG) in sub-Saharan Africa where HIV is most common. According to the National Academy of Medicine (NAM), GWG below and above NAM guidelines is associated with adverse birth outcomes. Therefore, the objective of this study was to describe GWG by HIV status and ART regimen, and examine the associations with adverse birth outcomes.

METHODS

We enrolled pregnant women with HIV (WHIV) and without HIV (≥18 years) in a peri-urban primary healthcare facility in Cape Town, South Africa between 2019 and 2022. GWG was study-measured at 24-28 (baseline) and 33-38 weeks gestation and converted to GWG rate (kg/week) in accordance with NAM guidelines. GWG z-scores were generated using the INTEGROWTH-21 and US standards to account for differing lengths of gestation. Birth outcome data were obtained from medical records. Associations of GWG z-score with adverse birth outcomes were assessed using multivariable linear or log-binomial regression.

RESULTS

Among 292 participants (48% WHIV), median age was 29 years (IQR, 25-33), median pre-pregnancy body mass index (BMI) was 31 kg/m2 (IQR, 26-36) and 20% were primiparous at baseline. The median weekly rate of GWG was 0.30 kg/week (IQR, 0.12-0.50), 35% had GWG below NAM standards (59% WHIV) and 48% had GWG above NAM standards (36% WHIV). WHIV gained weight more slowly (0.25 vs. 0.37 kg/week, p<0.01) than women without HIV. Weekly rate of GWG did not differ by ART regimen (DTG-based ART 0.25 vs. efavirenz-based ART 0.27 kg/week, p = 0.80). In multivariable analyses, GWG z-score was positively associated with continuous birth weight (mean difference = 68.53 95% CI 8.96, 128.10) and categorical high birth weight of >4000 g (RR = 2.18 95% CI 1.18, 4.01).

CONCLUSIONS

Despite slower GWG among WHIV, nearly half of all women gained weight faster than recommended by the NAM. GWG was positively associated with infant birth weight. Interventions to support healthy GWG in sub-Saharan Africa are urgently needed.

Interpregnancy Body Mass Index Change and Offspring Mortality Risk following the Second Pregnancy

OBJECTIVE

The aim of the study is to examine the impact of maternal interpregnancy body mass index (BMI) change on subsequent offspring mortality risk.

STUDY DESIGN

This is a retrospective cohort study of women who had two consecutive live singleton deliveries of at least 20 weeks' gestation from the Utah Population Database. Our exposure was defined as interpregnancy BMI change from the date of first delivery to the conception date of subsequent pregnancy. We categorized BMI change as: < - 1, -1 to 0, 0 to <1 (reference), 1 to 2, 2 to 4, ≥4 kg/m2. Our primary outcome was all-cause age-specific mortality during four time periods: neonatal (≤28 days), infant (29 days to <1 year old), childhood ((≥1 to <5 years old), and late childhood (5 to <18 years old). We also examined mortality specifically attributed to congenital anomalies. Analyses used Cox proportional hazard models stratified by full term (≥37 weeks) and preterm (<37 weeks) deliveries. All models were adjusted for relevant confounders.

RESULTS

Of 266,752 women, among full-term deliveries, women with a BMI increase of 4 kg/m2 or more had an increased risk of neonatal mortality in their subsequent pregnancy (hazard ratio or HR = 1.72, 95% confidence interval or CI: 1.23-2.41) Women who lost 1 kg/m2 or more between deliveries also had increased neonatal mortality (HR = 1.46, 95% CI: 1.04-2.05). There were no differences in infant, early, or late childhood mortality by interpregnancy BMI change. Maternal interpregnancy interval weight loss of 1 kg/m2 or more and weight gain of ≥4 kg/m2 also had increased risk of mortality associated with congenital anomalies or conditions arising during the neonatal period following their subsequent delivery.

CONCLUSION

Women with significant interpregnancy weight gain and modest weight loss have a significant increased risk of neonatal mortality following their subsequent pregnancy.

KEY POINTS

· Significant weight gain between deliveries increases the risk of neonatal death.. · Modest weight loss between deliveries increases the risk of neonatal death.. · This risk may be partially explained by increased risk of congenital malformations..

Comparison between the Brazilian and 3 international gestational weight gain charts

BACKGROUND

Little is known about the ability of the recently released Brazilian gestational weight gain (GWG) charts to predict the occurrence of adverse birth outcomes.

OBJECTIVES

We compared the new Brazilian weight gain charts with 3 international charts and determined their ability to predict the occurrence of small-for-gestational-age (SGA) and large-for-gestational-age (LGA) births in Brazilian women.

METHODS

A subsample of 6888 adult women (43,931 weight measurements) with singleton pregnancies from a nationwide, hospital-based cohort study conducted in 2011-2012 was analyzed. Selected percentiles from Brazilian GWG charts were compared with those from American, International Fetal and Newborn Growth Consortium for the 21st Century study, and Lifecycle consortium charts. Sensitivity, specificity, and AUROC values for SGA and LGA births were estimated with 95% CIs using the classification of GWG below or above selected percentiles of each chart.

RESULTS

The weight gain corresponding to a given percentile varied among the charts, especially for women with pre-pregnancy overweight and obesity. The proportions of women with GWG classified below or above selected percentiles were closest to the expected values for all pre-pregnancy BMI categories in the Brazilian and Lifecycle charts. At the 10th percentile, the highest sensitivity for SGA births was observed for the American charts at midpregnancy (36.8%) and the highest specificity was observed using the Brazilian charts in the first trimester (93.4%). At the 90th percentile, the highest sensitivity for LGA births occurred in midpregnancy for the Lifecycle charts (26.8%) and the highest specificity occurred in the American charts using total GWG (97.1%). All the AUROCs were under 0.5 for SGA births and ranged from 0.55 (first trimester) to 0.62 (total GWG) for LGA births.

CONCLUSIONS

The charts differ in GWG trajectories, especially for women with overweight and obesity. The 4 charts had low predictive ability of SGA and LGA births and should not be considered as isolated screening tools for those outcomes.

Influence of prenatal perceived stress on postpartum weight retention is mediated by high gestational weight gain in women with overweight

Women with excessive gestational weight gain (GWG) are at risk for poor psychosocial well-being and postpartum weight retention (PPWR). Scant research has examined longitudinal interrelations of GWG, psychosocial factors, and PPWR. This study examined: (a) pre-pregnancy weight status (ie, normal, overweight, obesity) differences in PPWR and its psychosocial determinants (perceived social support, perceived stress, depression) in women with excessive GWG (ie, above 2009 Institute of Medicine guidelines); and (b) whether GWG mediated associations between psychosocial determinants and PPWR. Women (N = 1352) reported third trimester perceived social support, perceived stress, and depressive symptoms, GWG, and 6- and 12-month PPWR via telephone interviews. Multivariate ANOVA analyses showed women with normal weight had higher 6-month PPWR than women with obesity; univariate ANOVA showed no group differences in psychosocial factors. Hayes mediation analyses indicated that GWG mediated the association between perceived stress and PPWR in women with overweight but not women with normal weight or obesity; perceived stress predicted GWG, and in turn, PPWR. Prenatal perceived stress may be a modifiable target of GWG and PPWR. Future research is needed to examine the utility of tailoring perinatal weight regulation interventions to reduce perceived stress in pregnant women with overweight.

Different methods for assessing gestational weight gain and its association with birth weight

OBJECTIVE

To analyze association of different methods of gestational weight gain assessment with live births small for gestational age (SGA) and large for gestational age (LGA).

METHODS

This was a cross-sectional study with adult women, normal prepregnancy BMI, single pregnancy and gestational age at delivery ≥28 weeks, from the "Birth in Brazil" study, between 2011 and 2012.

RESULTS

Among the 11,000 women participating in the study, prevalence of excessive weight gain was 33.1% according to the Brandão et al. and Institute of Medicine (IOM) methods, and 37.9% according to the Intergrowth method. The chance of being born SGA in the case of insufficient weight gain was OR=1.52 (95%CI 1.06;2.19), OR=1.52 (95%CI 1.05;2.20) and OR=1.56 (95%CI 1.06;2.30) for the Brandão et al., IOM and Intergrowth methods, respectively. Likelihood of excessive weight gain using the same methods was OR=1.53 (95%CI 1.28;1.82), OR=1.57 (95%CI 1.31;1.87) and OR=1.65 (95%CI 1.40;1.96), for LGA respectively.

CONCLUSION

Compared to the IOM recommendations, the Intergrowth and Brandão et al. methods show themselves to be alternatives for identifying SGA and LGA.

Excessive gestational weight gain and the risk of gestational diabetes: Comparison of Intergrowth-21st standards, IOM recommendations and a local reference

AIMS

To compare the abilities of Intergrowth-21st standards, Institute of Medicine (IOM) recommendations and a Chinese reference on gestational weight gain (GWG) to identify women at risk of gestational diabetes (GDM) and GDM-related adverse outcomes.

METHODS

A retrospective cohort study was conducted on 13,366 women delivering live singleton infants between 2013 and 2017 in Tongzhou district of Beijing, China. Poisson regression with robust error estimates was used to estimate risk ratios (RRs) of GDM in different GWG groups according to three standards.

RESULTS

There were 39.97%, 46.31% and 30.03% of women gaining weight above Intergrowth-21st standards, IOM recommendations and the Chinese reference respectively. Women with GWG above Intergrowth-21st standards and the Chinese reference had 27% (aRR, 1.27 95% CI, 1.18-1.37) and 30% (aRR, 1.30; 95% CI, 1.21-1.40) increased risks of GDM respectively, as compared to 22% (aRR, 1.22; 95% CI, 1.13-1.32) for IOM recommendations. GWG above either of these three standards was associated with macrosomia and cesarean delivery (P < 0.05).

CONCLUSION

Compared with IOM recommendations, GWG above Intergrowth-21st standards or the Chinese reference was associated with higher risks of GDM and GDM-related adverse outcomes. Furthermore, these two prospective standards could additionally assess the severity of abnormal GWG and are feasible for dynamic monitoring.

The influence of energy metabolism on postpartum weight retention

BACKGROUND

Profiling postpartum energy metabolism may assist in optimizing weight management following childbirth.

OBJECTIVES

The aims of this study were to profile total energy expenditure (TEE), resting energy expenditure (REE), exercise energy expenditure, sleep energy expenditure, and respiratory quotient in women at 3 and 9 mo postpartum (3M-PP, 9M-PP, respectively), and to examine the association between energy metabolism and postpartum weight retention (PPWR).

METHODS

In this cohort study, 1-h REE (measured in a whole body calorimetry unit, WBCU) and body composition (BC, measured by dual-energy X-ray absorptiometry) were measured at 3M-PP and 9M-PP (n = 49). Cardiorespiratory fitness [measured by the predicted maximal volume of oxygen consumption (p$\dot{V}$O2 max), n = 47] and 24-h TEE (WBCU, n = 43) were assessed only at 9M-PP. Women were stratified as high (>4.8 kg) or low (≤ 4.8 kg) weight retainers. Two-way mixed repeated-measures ANOVA and longitudinal regression models were applied. Linear regression was used to generate an equation at 3M-PP from the BC data, to predict the REE at 9M-PP.

RESULTS

The fat mass at 3M-PP was positively associated with PPWR at 3M-PP (mean ± SE β: 0.09 ± 0.03; P = 0.005) and 9M-PP (β: 0.11 ± 0.04; P = 0.008), and negatively associated with REE at 3M-PP (β: -0.16 ± 0.02; P < 0.001) and TEE at 9M-PP (β: -0.15 ± 0.03; P < 0.001). REE was negatively associated with PPWR (β: -0.74; 95% CI: -1.29, -0.19; P = 0.0087). REE was 2 kcal/kg higher in low- vs. high-retainers at 3M-PP, and REE and TEE were both 4 kcal/kg higher in low- vs. high-retainers at 9M-PP. Low-retainers demonstrated an increase in REE greater than expected for changes in BC. PPWR was negatively associated with TEE (β: -0.08 ± 0.02; P = 0.0009) and p$\dot{V}$O2 max (β: -0.02 ± 0.01; P = 0.047); p$\dot{V}$O2 max was 7 mL · kg-1 · min-1 higher in low- vs. high-retainers (P = 0.047).

CONCLUSIONS

Energy metabolism, BC, and cardiorespiratory fitness may be associated with weight regulation and its trajectory during the postpartum period. This provides the foundation for future strategies to promote appropriate postpartum weight management.

Interpregnancy weight change and perinatal outcomes: A protocol for a systematic review and meta-analysis

BACKGROUND

Growing evidence suggests that interpregnancy weight change (IPWC) is a risk factor for perinatal outcomes, since it may increase the probability of gestational complications including gestational diabetes or cesarean delivery. Additionally, IPWC may affect neonatal outcomes increasing the prevalence of newborns small for gestational age or preterm birth. However, the association between IPWC and perinatal outcomes has not systematically synthesized thus far. This study protocol aims to provide a clear, transparent and standardized procedure for systematically reviewing the association between IPWC and perinatal outcomes.

METHODS AND ANALYSIS

This systematic review and meta-analyses protocol is based on the preferred reporting items for systematic review and meta-analysis protocols and the Cochrane Collaboration Handbook. MEDLINE, EMBASE, the Cochrane Library, and Web of Science will be systematically searched from their inception. No limits will be defined by study design, as such different tools to assess risk of bias will be used:Odd ratios and their corresponding 95% confidence intervals will be reported to evaluate associations between IPWC and perinatal outcomes.

RESULTS

The results of this study will be published in a peer-reviewed journal.

CONCLUSION

This systematic review and meta-analysis will systematically synthesize the evidence regarding the association between IPWC and perinatal outcomes. Data will be extracted from published articles and findings will be published in peer-reviewed journals. Ethical approval and informed consent will not be required due to the nature of the study.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018100449.

The use of whole body calorimetry to compare measured versus predicted energy expenditure in postpartum women

BACKGROUND

Accurate assessment of energy expenditure may support weight-management recommendations. Measuring energy expenditure for each postpartum woman is unfeasible; therefore, accurate predictive equations are needed.

OBJECTIVES

This study compared measured with predicted resting energy expenditure (REE) and total energy expenditure (TEE) in postpartum women.

METHODS

This was a longitudinal observational study. REE was measured at 3 mo postpartum (n = 52) and 9 mo postpartum (n = 49), whereas TEE was measured once at 9 mo postpartum (n = 43) by whole body calorimetry (WBC). Measured REE (REEWBC) was compared with 17 predictive equations; measured TEE plus breast milk energy output (ERWBC) was compared with the estimated energy requirements/Dietary Reference Intakes equation (EERDRI). Fat and fat-free mass were measured by dual-energy X-ray absorptiometry. Group-level agreement was assessed by the Pearson correlation, paired t test, and Bland-Altman (bias) analyses. Individual-level accuracy was assessed with the use of Bland-Altman limits of agreement, and by the percentage of women with predicted energy expenditure within 10% of measured values ("accuracy").

RESULTS

The cohort was primarily Caucasian (90%). At a group level, the best equation predicting REEWBC was the DRI at 3 mo postpartum (-7 kcal, -0.1%; absolute and percentage bias, respectively), and the Harris-Benedict at 9 mo postpartum (-17 kcal, -0.5%). At an individual level, the Food and Agriculture Organization/World Health Organization/United Nations University (FAO/WHO/UNU) height and weight equation was the most accurate at 3 mo postpartum (100% accuracy) and 9 mo postpartum (98% accuracy), with the smallest limits of agreement. Equations including body composition variables were not more accurate. Compared with ERWBC, EERDRI bias was -36 kcal, with inaccurate predictions in 33% of women.

CONCLUSIONS

Many REE predictive equations were accurate for group assessment, with the FAO/WHO/UNU height and weight equation having the highest accuracy for individuals. EERDRI performed well at a group level, but inaccurately for 33% of women. A greater understanding of the physiology driving energy expenditure in the postpartum period is needed to better predict TEE and ultimately guide effective weight-management recommendations.

Early life environment influences the trajectory of post-partum weight loss in adult female rats

RESEARCH QUESTION

The physiological processes of pregnancy and lactation require profound changes in maternal metabolism and energy balance. The timescale of metabolic reversion after pregnancy, in particular post-partum weight loss, is highly variable between individuals. Currently, mechanisms influencing post-partum metabolic recovery are not well understood. The hypothesis tested here is that, in common with other metabolic and obesity-related outcomes, capacity for post-partum weight loss is influenced by developmental programming.

DESIGN

Adult female Wistar rats exposed to a maternal low-protein diet in utero then weaned onto a control diet post-natally (recuperated group) were compared with controls. Adult females from both groups underwent pregnancy at 3 months of age. Weight changes and metabolic parameters during pregnancy and lactation were compared between control and recuperated groups, and also with non-pregnant littermates.

RESULTS

Pregnancy weight gain was not different between the control and recuperated groups, but post-partum recuperated animals remained significantly heavier than both post-partum control animals (P<0.05) and their non-pregnant recuperated littermates (P<0.05) at the end of lactation. Post-partum recuperated animals had more intra-abdominal fat mass (P<0.05) and higher serum triglyceride concentrations (P<0.01) than controls. Post-partum recuperated animals also had increased expression of IL6, NRF2 and ALOX12 (key regulators of inflammation and lipoxygenase activity) in the intra-abdominal adipose tissue compared with control groups.

CONCLUSIONS

Mothers who themselves have been exposed to adverse early life environments are likely to have slower metabolic recovery from pregnancy than controls. Failure to return to pre-pregnancy weight after delivery predisposes to persisting sequential inter-pregnancy weight gain, which can represent a significant metabolic burden across a life course involving several pregnancies.

Gestational weight gain charts for different body mass index groups for women in Europe, North America, and Oceania

BACKGROUND

Gestational weight gain differs according to pre-pregnancy body mass index and is related to the risks of adverse maternal and child health outcomes. Gestational weight gain charts for women in different pre-pregnancy body mass index groups enable identification of women and offspring at risk for adverse health outcomes. We aimed to construct gestational weight gain reference charts for underweight, normal weight, overweight, and grades 1, 2 and 3 obese women and to compare these charts with those obtained in women with uncomplicated term pregnancies.

METHODS

We used individual participant data from 218,216 pregnant women participating in 33 cohorts from Europe, North America, and Oceania. Of these women, 9065 (4.2%), 148,697 (68.1%), 42,678 (19.6%), 13,084 (6.0%), 3597 (1.6%), and 1095 (0.5%) were underweight, normal weight, overweight, and grades 1, 2, and 3 obese women, respectively. A total of 138, 517 women from 26 cohorts had pregnancies with no hypertensive or diabetic disorders and with term deliveries of appropriate for gestational age at birth infants. Gestational weight gain charts for underweight, normal weight, overweight, and grade 1, 2, and 3 obese women were derived by the Box-Cox t method using the generalized additive model for location, scale, and shape.

RESULTS

We observed that gestational weight gain strongly differed per maternal pre-pregnancy body mass index group. The median (interquartile range) gestational weight gain at 40 weeks was 14.2 kg (11.4-17.4) for underweight women, 14.5 kg (11.5-17.7) for normal weight women, 13.9 kg (10.1-17.9) for overweight women, and 11.2 kg (7.0-15.7), 8.7 kg (4.3-13.4) and 6.3 kg (1.9-11.1) for grades 1, 2, and 3 obese women, respectively. The rate of weight gain was lower in the first half than in the second half of pregnancy. No differences in the patterns of weight gain were observed between cohorts or countries. Similar weight gain patterns were observed in mothers without pregnancy complications.

CONCLUSIONS

Gestational weight gain patterns are strongly related to pre-pregnancy body mass index. The derived charts can be used to assess gestational weight gain in etiological research and as a monitoring tool for weight gain during pregnancy in clinical practice.

Healthcare providers' gestational weight gain counselling practises and the influence of knowledge and attitudes: a cross-sectional mixed methods study

OBJECTIVE

To understand current gestational weight gain (GWG) counselling practices of healthcare providers, and the relationships between practices, knowledge and attitudes.

DESIGN

Concurrent mixed methods with data integration: cross-sectional survey and semistructured interviews.

PARTICIPANTS

Prenatal healthcare providers in Canada: general practitioners, obstetricians, midwives, nurse practitioners and registered nurses in primary care settings.

RESULTS

Typically, GWG information was provided early in pregnancy, but not discussed again unless there was a concern. Few routinely provided women with individualised GWG advice (21%), rate of GWG (16%) or discussed the risks of inappropriate GWG to mother and baby (20% and 19%). More routinely discussed physical activity (46%) and food requirements (28%); midwives did these two activities more frequently than all other disciplines (P<0.001). Midwives interviewed noted a focus on overall wellness instead of weight, and had longer appointment times which allowed them to provide more in-depth counselling. Regression results identified that the higher priority level that healthcare providers place on GWG, the more likely they were to report providing GWG advice and discussing risks of GWG outside recommendations (β=0.71, P<0.001) and discussing physical activity and food requirements (β=0.341, P<0.001). Interview data linked the priority level of GWG to length of appointments, financial compensation methods for healthcare providers and the midwifery versus medical model of care.

CONCLUSIONS

Interventions for healthcare providers to enhance GWG counselling practices should consider the range of factors that influence the priority level healthcare providers place on GWG counselling.