Maternal body mass index and the risk of fetal death, stillbirth, and infant death: a systematic review and meta-analysis

Metformin use in obese mothers is associated with improved cardiovascular profile in the offspring

BACKGROUND

Maternal obesity increases the risk for pregnancy complications and adverse neonatal outcome and has been associated with long-lasting adverse effects in the offspring, including increased body fat mass, insulin resistance, and increased risk for premature cardiovascular disease. Lifestyle interventions in pregnancy have produced no or modest effects in the reduction of adverse pregnancy outcomes in obese mothers. The Metformin in Obese Pregnant Women trial was associated with reduced adverse pregnancy outcomes and had no effect on birthweight. However, the long-term implications of metformin on the health of offspring remain unknown.

OBJECTIVE

The purpose of this study was to assess whether prenatal exposure to metformin can improve the cardiovascular profile and body composition in the offspring of obese mothers.

STUDY DESIGN

In 151 children from the Metformin in Obese Pregnant Women trial, body composition, peripheral blood pressure, and arterial pulse wave velocity were measured. Central hemodynamics (central blood pressure and augmentation index) were estimated with the use of an oscillometric device. Left ventricular cardiac function and structure were assessed by echocardiography.

RESULTS

Children were 3.9±1.0 years old, and 77 of them had been exposed to metformin prenatally. There was no significant difference in peripheral blood pressure, arterial stiffness, and body composition apart from gluteal and tricep circumferences, which were lower in the metformin group (P<.05). The metformin group, compared with the placebo group, had lower central hemodynamics (mean adjusted decrease, -0.707 mm Hg for aortic systolic blood pressure, -1.65 mm Hg for aortic pulse pressure, and -2.68% for augmentation index; P<.05 for all) and lower left ventricular diastolic function (adjusted difference in left atrial area, -0.525 cm², in isovolumic relaxation time, -0.324 msec, and in pulmonary venous systolic wave, 2.97 cm/s; P<.05 for all). There were no significant differences in metabolic profile between the groups.

CONCLUSION

Children of obese mothers who were exposed prenatally to metformin, compared with those who were exposed to placebo, had lower central hemodynamic and cardiac diastolic indices. These results suggest that the administration of metformin in obese pregnant women potentially may have a beneficial cardiovascular effect for their offspring.

Is obesity in pregnancy associated with signs of chronic fetal hypoxia?

INTRODUCTION

The prevalence of obesity in pregnancy is increasing worldwide. Maternal obesity increases risks of severe fetal and neonatal complications. The underlying pathophysiological mechanisms are unclear. One possible contributing factor could be chronic fetal hypoxia. The aim of this study was to compare placentas from women with and without obesity with respect to placental lesions, which could reflect compensatory mechanisms in response to chronic fetal hypoxia as well as lesions possibly leading to chronic fetal hypoxia. In addition, levels of erythropoietin in cord blood were compared between offspring of lean and obese women.

MATERIAL AND METHODS

This cohort study included 180 women with uneventful, full-term, singleton pregnancies, out of which 91 lean women had a body mass index (BMI) of 18.5-24.9 kg/m² and 89 women had obesity (BMI ≥30 kg/m² ). Women were recruited at Södersjukhuset between 16 October 2018 and 2 December 2019. Placentas were investigated by two senior perinatal pathologists, who were blinded for maternal BMI. Cord blood was analyzed for levels of erythropoietin.

RESULTS

Levels of erythropoietin in cord blood increased with maternal BMI (P = .01, β = 0.97, 95% CI 0.27-1.68). There was no difference between placentas of obese and lean women in number of placental lesions reflecting chronic fetal hypoxia or in lesions that could possibly lead to chronic fetal hypoxia.

CONCLUSIONS

This study of term and uneventful pregnancies demonstrated a positive association between maternal obesity and concentrations of erythropoietin in cord blood at birth. This finding supports the hypothesis of chronic fetal hypoxia as a risk factor for complications in the pregnancies of obese women. There were no differences in lesions associated with hypoxia between placentas of obese and lean women.

Body mass index increases the lymph node metastasis risk of breast cancer: a dose-response meta-analysis with 52904 subjects from 20 cohort studies

Background

Since body mass index (BMI) is a convincing risk factor for breast cancer, it is speculated to be associated with lymph node metastasis. However, epidemiological studies are inconclusive. Therefore, this study was conducted to investigate the effect of BMI on the lymph node metastasis risk of breast cancer.

Methods

Cohort studies that evaluating BMI and lymph node metastasis in breast cancer were selected through various databases including PubMed, PubMed Central (PMC), Web of science, the China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals (VIP) and Wanfang Data Knowledge Service Platform (WanFang) until November 30, 2019. The two-stage, random effect meta-analysis was performed to assess the dose-response relationship between BMI and lymph node metastasis risk. Between-study heterogeneity was assessed using I². Subgroup analysis was done to find possible sources of heterogeneity.

Results

We included a total of 20 studies enrolling 52,904 participants. The summary relative risk (RR) (1.10, 95%CI: 1.06–1.15) suggested a significant effect of BMI on the lymph node metastasis risk of breast cancer. The dose-response meta-analysis (RR = 1.01, 95%CI: 1.00–1.01) indicated a positive linear association between BMI and lymph node metastasis risk. For every 1 kg/m² increment of BMI, the risk of lymph node metastasis increased by 0.89%. In subgroup analyses, positive linear dose-response relationships between BMI and lymph node metastasis risk were observed among Asian, European, American, premenopausal, postmenopausal, study period less than 5 years, and more than 5 years groups. For every 1 kg/m² increment of BMI, the risk of lymph node metastasis increased by 0.99, 0.85, 0.61, 1.44, 1.45, 2.22, and 0.61%, respectively.

Conclusion

BMI significantly increases the lymph node metastasis risk of breast cancer as linear dose-response reaction. Further studies are needed to identify this association.

Reaching women with obesity to support weight loss before pregnancy: feasibility and qualitative assessment

Background:

We sought to assess attitudes toward weight and barriers to recruitment of women with obesity for a potential preconception weight-loss/lifestyle modification intervention.

Methods:

We performed a qualitative study involving women of reproductive age (18–45) with obesity (body mass index ⩾30 kg/m²) who were considering a pregnancy in the next 2 years. We evaluated four methods of recruitment. We used previously validated survey questions to evaluate risk perceptions. In a subset, we used semistructured interviews for topics that required more in-depth information: domains included attitudes toward weight-related issues, intentions, and barriers to engagement in a structured weight-loss program. We performed qualitative analyses of interview transcripts using immersion crystallization.

Results:

We recruited the majority (80/82, 98%) of women using e-recruitment strategies. Eighty-one women filled out the survey and 39 completed an interview. Three-quarters of the women surveyed (60 of 81) reported attempts to lose weight in the past year and 77% (68/81) of survey respondents cited jobs and work schedules as a barrier to adopting healthy habits. More than 87% (34 of 39) of women interviewed reported willingness to participate in a structured weight-loss program prior to getting pregnant. Of these, 74% (25 of 34) stated they would consider delaying their attempts at a future pregnancy in order to participate in such a program.

Conclusions:

E-recruitment is a promising strategy for recruitment for preconception weight-loss and lifestyle modification program. Most women state a willingness to delay pregnancy attempts to participate in a weight-loss program.

Pre-pregnancy maternal obesity, macrosomia, and risk of stillbirth: A population-based study

OBJECTIVE

An examination of the synergistic effects of maternal obesity and macrosomia on the risk of stillbirth is lacking. The purpose of this study was to determine the association between fetal macrosomia, maternal obesity, and the risk of stillbirth.

METHODS

This retrospective cross-sectional study used the CDC's Birth Data and Fetal Death Data files for 2014-2017 [n = 10,043,398‬ total births; including 48,799 stillbirths]. The exposure was fetal macrosomia stratified by obesity subtypes (I-III). The outcome was the risk of stillbirth. We also controlled for potential and known confounding factors in adjusted models. Adjusted Relative Risks (ARR) were estimated with log-binomial regression models.

RESULTS

The rate of stillbirth was higher among macrosomic infants born to mothers with obesity compared to those without (6.55 vs. 0.54 per 1000 total births). After controlling for confounding, women with obesity types II and III were at increased risk for stillbirth [Obesity II ARR = 2.37 (2.07-2.72); Obesity III ARR = 9.06 (7.61-10.78)].

CONCLUSIONS FOR PRACTICE

Obesity-related fetal overgrowth is a significant risk factor for stillbirth, especially among women with type II and type III obesity. This finding highlights the need for more effective clinical and public health strategies to address pre-pregnancy obesity and to optimize gestational weight gain.

Outcomes of Elective Induction of Labor versus Expectant Management among Obese Women at ≥39 Weeks

OBJECTIVE

Maternal obesity is associated with many adverse obstetric outcomes including cesarean delivery. It is unclear whether induction of labor can reduce these risks. Previous studies report conflicting results on the outcomes of elective induction of labor among obese women. This study aimed to compare maternal and neonatal outcomes between obese women undergoing elective induction of labor and those undergoing expectant management at ≥39 weeks.

STUDY DESIGN

This was a retrospective cohort study from the Consortium on Safe Labor of obese women (defined by prepregnancy body mass index≥ 30kg/m²) with singleton gestations at ≥39 weeks without medical comorbidities from 2002 through 2008. Women scheduled for medically indicated induction of labor were excluded. The primary outcome of cesarean delivery was compared between obese women undergoing elective induction of labor and expectant management during 39th, 40th, and 41st weeks using univariable and multivariable analyses, stratifying by parity.

RESULTS

In all, 7,298 nulliparous and 9,789 parous women were eligible for analysis. After controlling for potential confounders, elective induction of labor during 39th week in nulliparous and parous women was associated with lower odds of cesarean delivery (39.1 vs. 41.6%, adjusted odds ratio [OR]: 0.47, 95% confidence interval [CI]: 0.30-0.74 for nulliparous and 5.5 vs. 10.1%, adjusted OR: 0.34, 95% CI: 0.20-0.61 for parous women) compared with expectant management. Elective induction of labor during 40th and 41st weeks was not associated with lower odds of cesarean delivery. In addition, macrosomia was reduced in nulliparous women undergoing elective induction of labor during the 40th week (12.1 vs. 18.5%, adjusted OR: 0.56, 95% CI: 0.35-0.87) and in parous women undergoing elective induction of labor during 39th (11.6 vs. 17.6%, adjusted OR: 0.50, 95% CI: 0.38-0.66) and 40th weeks (16.4 vs. 22.2%, adjusted OR: 0.53, 95% CI: 0.36-0.78).

CONCLUSION

Elective induction of labor at 39 weeks, when compared with expectant management, was associated with lower cesarean deliveries in obese nulliparous and parous women.

Association Between Maternal Prepregnancy Body Mass Index and Anthropometric Parameters, Blood Pressure, and Retinal Microvasculature in Children Age 4 to 6 Years

IMPORTANCE

Maternal prepregnancy body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) has previously been associated with offspring cardiometabolic risk factors, such as fat mass, glucose and insulin levels, and blood pressure, but these associations appear to be largely mediated by offspring BMI. To our knowledge, no studies have assessed alterations in the retinal microvasculature in association with maternal prepregnancy BMI.

OBJECTIVE

To investigate the association between maternal prepregnancy BMI and anthropometric parameters, blood pressure, and retinal vessel parameters in children age 4 to 6 years.

DESIGN, SETTING, AND PARTICIPANTS

Participants included mother-child pairs of the population-based Environmental Influence on Early Aging (ENVIRONAGE) birth cohort study (Flanders, Belgium) who were recruited at birth from February 2010 to June 2014 and followed-up at age 4 to 6 years between October 2014 and July 2018. Data were analyzed from February 2019 to April 2019.

EXPOSURES

Maternal prepregnancy BMI based on height and weight measurements at the first antenatal visit (weeks 7-9 of gestation).

MAIN OUTCOMES AND MEASURES

Children's anthropometric, blood pressure, and retinal microcirculation measurements at age 4 to 6 years. Retinal vessel diameters and the tortuosity index, a measure for the curvature of the retinal vasculature, were obtained by fundus image analysis.

RESULTS

This study included 240 mothers and children with a mean (SD) age of 29. 9 (4.2) years and 54.8 (4.7) months, respectively. Of these, 114 children (47.5%) were boys. Maternal prepregnancy BMI was positively associated with the child's birth weight, BMI, waist circumference, blood pressure, and retinal vessel tortuosity. A 1-point increase in maternal prepregnancy BMI was associated with a 0.26-mm Hg (95% CI, 0.08-0.44) higher mean arterial pressure for their children, with similar estimates for systolic and diastolic blood pressure. Independent from the association with blood pressure, a 1-point increase in maternal prepregnancy BMI was associated with a 0.40 (95% CI, 0.01-0.80) higher retinal tortuosity index (× 103). The hypothesis that these associations reflect direct intrauterine mechanisms is supported by the following observations: associations were independent of the current child's BMI and the estimates for paternal BMI at the follow-up visit did not reach significance.

CONCLUSIONS AND RELEVANCE

Considering that blood pressure tracks from childhood into adulthood and microvascular changes may be early markers of cardiometabolic disease development, our results suggest that maternal prepregnancy BMI is an important modifiable risk factor for later-life cardiovascular health of the offspring.

Surrogacy and Pregnancy

Importance

Surrogacy allows for parenthood when it is otherwise impossible or exceedingly difficult; however, the risks of surrogate pregnancy for the gestational surrogate and the fetus are not well defined.

Objective

The aim of this study was to review the literature to examine the prevalence and requirements of surrogate pregnancy and maternal and perinatal outcomes.

Evidence Acquisition

A CINAHL and 2 PubMed searches were undertaken using the terms "surrogate mothers" OR "(surrogate or surrogacy)" AND "(mothers OR pregnancy OR pregnant)." The second search used these terms and pregnancy outcomes. The search was limited to the English language, but the years searched were unlimited.

Results

The search identified 153 articles, 36 of which are the basis for this review. The number of surrogate pregnancies is increasing in the United States. Fetal risks associated with surrogacy include low birth weight, increased risk of multiple gestation, and preterm birth. Maternal complications associated with surrogate pregnancy include hypertensive disorders of pregnancy, postpartum hemorrhage, and gestational diabetes.

Conclusions and Relevance

Surrogacy is a route to parenting that is not without risk to the surrogate or the fetus, and surrogate pregnancy is increasing in frequency in the United States.

Maternal Obesity and Diabetes Mellitus as Risk Factors for Congenital Heart Disease in the Offspring

Congenital heart disease (CHD) is the most common anatomical malformation occurring live‐born infants and an increasing cause of morbidity and mortality across the lifespan and throughout the world. Population‐based observations have long described associations between maternal cardiometabolic disorders and the risk of CHD in the offspring. Here we review the epidemiological evidence and clinical observations relating maternal obesity and diabetes mellitus to the risk of CHD offspring with particular attention to mechanistic models of maternal‐fetal risk transmission and first trimester disturbances of fetal cardiac development. A deeper understanding of maternal risk factors holds the potential to improve both prenatal detection of CHD by identifying at‐risk pregnancies, along with primary prevention of disease by improving preconception and prenatal treatment of at‐risk mothers.

Changes in Maternal Body Mass Index, Weight Gain and Outcome of Singleton Pregnancies from 2000 to 2015: A Population-based Retrospective Cohort Study in Hesse/Germany

Introduction Maternal obesity and excessive gestational weight gain (GWG) affect the outcomes of women and their offspring. Our aim was to evaluate population-based data from Germany.

Material and Methods Data from 583 633/791 514 mother-child pairs obtained from the perinatal database in Hesse for the period from 2000 to 2015 were used after excluding incomplete or non-plausible datasets. Early-stage pregnancy maternal body mass index (BMI) and GWG were evaluated. Significant outcome changes were calculated using linear or logistic regression models.

Results The mean maternal age increased from 29.9 to 31.28 years; GWG increased from 445.1 to 457.2 g/week (p < 0.01). Similarly, rates for both overweight and obesity rose from 31.5 to 37.5% (p < 0.001). Cesarean section rates rose from 22.8 to 33.2% (p < 0.001) and rates of postpartum hemorrhage increased from 0.6 to 1% (p < 0.001). There was no significant change in the rates for stillbirth or perinatal mortality (p = 0.92 and p = 0.53 respectively), but there was an increase in the rates of admissions to neonatal intensive care units from 7.8 to 9.5% (p < 0.0001). The percentage of newborns with an Apgar score of < 7 at 5 minutes increased from 1 to 1.1% (p < 0.01) and the rate of neonates with an umbilical artery pH of < 7.1 rose from 1.7 to 2.4% (p < 0.01).

Conclusions In just 15 years, pre-pregnancy BMI and GWG rates of women with singleton pregnancies have increased, and this increase has been accompanied by a significant rise in the rate of cesarean sections and a significant worsening of short-term maternal and neonatal outcomes. It is time to discuss the risks and the short-term and more worrying long-term consequences for mothers and their offspring and the future impact on our healthcare system.

Understanding high rates of stillbirth and neonatal death in a disadvantaged, high-migrant district in France: A perinatal audit

INTRODUCTION

The objective of this study is to investigate factors associated with risks of perinatal death in a disadvantaged, high-migrant French district with mortality rates above the national average.

MATERIAL AND METHODS

The study design is a perinatal audit in 2014 in all 11 maternity units in the Seine-Saint-Denis district (25 037 births). The data come from medical chart abstraction, maternal interviews and peer assessor confidential review of deaths. A representative sample of live births in the same district, from the 2010 French Perinatal Survey, was used for comparisons (n = 429). The main outcome measures were stillbirth and neonatal death (0-27 days) at ≥22 weeks of gestation.

RESULTS

The audit included 218 women and 227 deaths (156 stillbirths, 71 neonatal deaths); 75 women were interviewed. In addition to primiparity and multiple pregnancy, overweight and obesity increased mortality risks (50% of cases, adjusted odds ratios [aOR] 1.7, 95% confidence interval [CI] 1.1-2.8, and aOR 1.9 [95% CI 1.1-3.2], respectively) as did the presence of preexisting medical/obstetric conditions (28.6% of cases, aOR 3.2, 95% CI 2.0-5.3). Problems accessing or complying with care were noted in 25% of medical records and recounted in 50% of interviews. Assessors identified suboptimal factors in 73.2% of deaths and judged 33.9% to be possibly or probably preventable. Care not adapted to risk factors and poor healthcare coordination were frequent suboptimal factors. Possibly preventable deaths were higher (P < .05) for women with gestational diabetes or hypertension (44.6%) than women without (29.0%).

CONCLUSIONS

Preventive actions to improve healthcare referral and coordination, especially for overweight and obese women and women with medical and obstetrical risk factors, could reduce perinatal mortality in disadvantaged areas.

Kidney function, blood pressure and proteinuria were associated with pregnancy outcomes of pregnant women with chronic kidney disease: a single-center, retrospective study in the Asian population

BACKGROUND

Studies among pregnant Asian women with chronic kidney disease (CKD) have not been widely performed; therefore, clinical criteria for these patients have not been well established.

METHODS

We conducted a retrospective study among pregnant women with CKD who received prenatal care at our institution for 8 consecutive years. Primary outcome was the development of severe adverse events (SAEs). We analyzed correlations between primary outcome and CKD parameters [age, body mass index (BMI), estimated glomerular filtration rate (eGFR), urinary protein-creatinine ratio (UP), systolic blood pressure (SBP), diastolic blood pressure (DBP), and not normal blood pressure (non-NBP)] at the time of referral. Secondary outcomes were low birth weight (LBW), preterm delivery (PreD), and small for gestational age (SGA). We divided into two categories, CKD stage G1, and G2 or higher according to eGFR, and proteinuria negative and proteinuria positive according to UP, respectively.

RESULTS

We observed 89 pregnancies. SAE was observed in 28 pregnancies. In live birth cases, there were 28 PreD, 28 LBW and 13 SGA. Major SAEs included preeclampsia, superimposed preeclampsia, unscheduled cesarean section, neonatal intensive care unit admission, and fetal death. Stepwise logistic regression analysis selected eGFR (OR = 0.847, p = 0.026), SBP (OR = 1.897, p = 0.006) and proteinuria positive (OR = 2.96, p = 0.046) as the significant predictors of SAEs. There were no significant differences among the baseline characteristics stratified by SGA.

CONCLUSIONS

This is the first study to report pregnancy outcomes among Japanese non-disease-oriented patients with CKD. In Asians, especially in the Japanese population, kidney function, blood pressure and proteinuria might affect pregnancy outcomes.

Text messaging to help women with overweight or obesity lose weight after childbirth: the intervention adaptation and SMS feasibility RCT

Background

There is a need to develop weight management interventions that fit seamlessly into the busy lives of women during the postpartum period.

Objective

The objective was to develop and pilot-test an evidence- and theory-based intervention, delivered by short message service, which supported weight loss and weight loss maintenance in the postpartum period.

Design

Stage 1 involved the development of a library of short message service messages to support weight loss and weight loss maintenance, with personal and public involvement, focusing on diet and physical activity with embedded behaviour change techniques, and the programming of a short message service platform to allow fully automated intervention delivery. Stage 2 comprised a 12-month, single-centre, two-arm, pilot, randomised controlled trial with an active control.

Setting

This study was set in Northern Ireland; women were recruited via community-based approaches.

Participants

A total of 100 women with overweight or obesity who had given birth in the previous 24 months were recruited.

Interventions

The intervention group received an automated short message service intervention about weight loss and weight loss maintenance for 12 months. The active control group received automated short message service messages about child health and development for 12 months.

Main outcome measures

The main outcomes measured were the feasibility of recruitment and retention, acceptability of the intervention and trial procedures, and evidence of positive indicative effects on weight. Weight, waist circumference and blood pressure were measured by the researchers; participants completed a questionnaire booklet and wore a sealed pedometer for 7 days at baseline, 3, 6, 9 and 12 months. Outcome assessments were collected during home visits and women received a voucher on completion of each of the assessments. Qualitative interviews were conducted with women at 3 and 12 months, to gather feedback on the intervention and active control and the study procedures. Quantitative and qualitative data were used to inform the process evaluation and to assess fidelity, acceptability, dose, reach, recruitment, retention, contamination and context.

Results

The recruitment target of 100 participants was achieved (intervention, n = 51; control, n = 49); the mean age was 32.5 years (standard deviation 4.3 years); 28 (28%) participants had a household income of < £29,999 per annum. Fifteen women became pregnant during the follow-up (intervention, n = 9; control, n = 6) and withdrew from the study for this reason. At the end of the 12-month study, the majority of women remained in the study [85.7% (36/42) in the intervention group and 90.7% (39/43) in the active control group]. The research procedures were well accepted by women. Both groups indicated a high level of satisfaction with the short message service intervention that they were receiving. There was evidence to suggest that the intervention may have a positive effect on weight loss and prevention of weight gain during the postpartum period.

Limitations

The interviews at 3 and 12 months were conducted by the same researchers who collected other outcome data.

Conclusions

An evidence- and theory-based intervention delivered by short message service was successfully developed in conjunction with postpartum women with overweight and obesity. The intervention was acceptable to women and was feasible to implement in the 12-month pilot randomised controlled trial. The progression criteria for a full randomised controlled trial to examine effectiveness and cost-effectiveness were met.

Future work

Some minor refinements need to be made to the intervention and trial procedures based on the findings of the pilot trial in preparation for conducting a full randomised controlled trial.

Trial registration

Current Controlled Trial ISRCTN90393571.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 8, No. 4. See the NIHR Journals Library website for further project information. The intervention costs were provided by the Public Health Agency, Northern Ireland.

Obstetric Care Consensus #10: Management of Stillbirth: (Replaces Practice Bulletin Number 102, March 2009)

Stillbirth is one of the most common adverse pregnancy outcomes, occurring in 1 in 160 deliveries in the United States. In developed countries, the most prevalent risk factors associated with stillbirth are non-Hispanic black race, nulliparity, advanced maternal age, obesity, preexisting diabetes, chronic hypertension, smoking, alcohol use, having a pregnancy using assisted reproductive technology, multiple gestation, male fetal sex, unmarried status, and past obstetric history. Although some of these factors may be modifiable (such as smoking), many are not. The study of specific causes of stillbirth has been hampered by the lack of uniform protocols to evaluate and classify stillbirths and by decreasing autopsy rates. In any specific case, it may be difficult to assign a definite cause to a stillbirth. A significant proportion of stillbirths remains unexplained, even after a thorough evaluation. Evaluation of a stillbirth should include fetal autopsy; gross and histologic examination of the placenta, umbilical cord, and membranes; and genetic evaluation. The method and timing of delivery after a stillbirth depend on the gestational age at which the death occurred, maternal obstetric history (eg, previous hysterotomy), and maternal preference. Health care providers should weigh the risks and benefits of each strategy in a given clinical scenario and consider available institutional expertise. Patient support should include emotional support and clear communication of test results. Referral to a bereavement counselor, peer support group, or mental health professional may be advisable for management of grief and depression.

Management of Stillbirth: Obstetric Care Consensus No, 10

Stillbirth is one of the most common adverse pregnancy outcomes, occurring in 1 in 160 deliveries in the United States. In developed countries, the most prevalent risk factors associated with stillbirth are non-Hispanic black race, nulliparity, advanced maternal age, obesity, preexisting diabetes, chronic hypertension, smoking, alcohol use, having a pregnancy using assisted reproductive technology, multiple gestation, male fetal sex, unmarried status, and past obstetric history. Although some of these factors may be modifiable (such as smoking), many are not. The study of specific causes of stillbirth has been hampered by the lack of uniform protocols to evaluate and classify stillbirths and by decreasing autopsy rates. In any specific case, it may be difficult to assign a definite cause to a stillbirth. A significant proportion of stillbirths remains unexplained even after a thorough evaluation. Evaluation of a stillbirth should include fetal autopsy; gross and histologic examination of the placenta, umbilical cord, and membranes; and genetic evaluation. The method and timing of delivery after a stillbirth depend on the gestational age at which the death occurred, maternal obstetric history (eg, previous hysterotomy), and maternal preference. Health care providers should weigh the risks and benefits of each strategy in a given clinical scenario and consider available institutional expertise. Patient support should include emotional support and clear communication of test results. Referral to a bereavement counselor, peer support group, or mental health professional may be advisable for management of grief and depression.

Multilevel analyses of related public health indicators: The European Surveillance of Congenital Anomalies (EUROCAT) Public Health Indicators

BACKGROUND

Public health organisations use public health indicators to guide health policy. Joint analysis of multiple public health indicators can provide a more comprehensive understanding of what they are intended to evaluate.

OBJECTIVE

To analyse variaitons in the prevalence of congenital anomaly-related perinatal mortality attributable to termination of pregnancy for foetal anomaly (TOPFA) and prenatal diagnosis of congenital anomaly prevalence.

METHODS

We included 55 363 cases of congenital anomalies notified to 18 EUROCAT registers in 10 countries during 2008-12. Incidence rate ratios (IRR) representing the risk of congenital anomaly-related perinatal mortality according to TOPFA and prenatal diagnosis prevalence were estimated using multilevel Poisson regression with country as a random effect. Between-country variation in congenital anomaly-related perinatal mortality was measured using random effects and compared between the null and adjusted models to estimate the percentage of variation in congenital anomaly-related perinatal mortality accounted for by TOPFA and prenatal diagnosis.

RESULTS

The risk of congenital anomaly-related perinatal mortality decreased as TOPFA and prenatal diagnosis prevalence increased (IRR 0.79, 95% confidence interval [CI] 0.72, 0.86; and IRR 0.88, 95% CI 0.79, 0.97). Modelling TOPFA and prenatal diagnosis together, the association between congenital anomaly-related perinatal mortality and TOPFA prevalence became stronger (RR 0.70, 95% CI 0.61, 0.81). The prevalence of TOPFA and prenatal diagnosis accounted for 75.5% and 37.7% of the between-country variation in perinatal mortality, respectively.

CONCLUSION

We demonstrated an approach for analysing inter-linked public health indicators. In this example, as TOPFA and prenatal diagnosis of congenital anomaly prevalence decreased, the risk of congenital anomaly-related perinatal mortality increased. Much of the between-country variation in congenital anomaly-related perinatal mortality was accounted for by TOPFA, with a smaller proportion accounted for by prenatal diagnosis.

Association of Overweight and Obesity Development Between Pregnancies With Stillbirth and Infant Mortality in a Cohort of Multiparous Women

OBJECTIVE

To identify the association of newly developed prepregnancy overweight and obesity with stillbirth and infant mortality.

METHODS

We studied subsequent pregnancies of mothers who were normal weight at fertilization of their first identified pregnancy, from a population-based cohort that linked birth registry with death records in Pennsylvania, 2003-2013. Women with newly developed prepregnancy overweight and obesity were defined as those whose body mass index (BMI) before second pregnancy was between 25 and 29.9 or 30 or higher, respectively. Our main outcomes of interest were stillbirth (intrauterine death at 20 weeks of gestation or greater), infant mortality (less than 365 days after birth), neonatal death (less than 28 days after birth) and postneonatal death (29-365 days after birth). Associations of both prepregnancy BMI categories and continuous BMI with each outcome were estimated by nonparametric targeted minimum loss-based estimation and inverse-probability weighted dose-response curves, respectively, adjusting for race-ethnicity, smoking, and other confounders (eg, age, education).

RESULTS

A cohort of 212,889 women were included for infant mortality analysis (192,941 women for stillbirth analysis). The crude rate of stillbirth and infant mortality in these final analytic cohorts were 3.3 per 1,000 pregnancies and 2.9 per 1,000 live births, respectively. Compared with women who stayed at a normal weight in their second pregnancies, those becoming overweight had 1.4 (95% CI 0.6-2.1) excess stillbirths per 1,000 pregnancies. Those becoming obese had 3.6 (95% CI 1.3-5.9) excess stillbirths per 1,000 pregnancies and 2.4 (95% CI 0.4-4.4) excess neonatal deaths per 1,000 live births. There was a dose-response relationship between prepregnancy BMI increases of more than 2 units and increased risk of stillbirth and infant mortality. In addition, BMI increases were associated with higher risks of infant mortality among women with shorter interpregnancy intervals (less than 18 months) compared with longer intervals.

CONCLUSION

Transitioning from normal weight to overweight or obese between pregnancies was associated with an increased risk of stillbirth and neonatal mortality.

Timing of Gestational Weight Gain and Adverse Perinatal Outcomes in Overweight and Obese Women

OBJECTIVE

To evaluate whether inadequate or excessive gestational weight gain before the third trimester is associated with adverse pregnancy outcomes, and to evaluate the association of weight gain in the third trimester with fetal growth.

METHODS

This was a retrospective cohort study of all eligible overweight and obese women with singleton pregnancies delivered at an academic institution between 2012 and 2014. Our primary exposure was inadequate or excess gestational weight gain during the first and second trimesters. Outcomes included small- (SGA) or large- (LGA) for-gestational-age birth weight as well adverse maternal outcomes and composite neonatal morbidity. Multivariable logistic regression was used to assess the relationship between weight gain and perinatal outcomes, and stratified analyses evaluated the relationship between third trimester weight gain and birth weight category.

RESULTS

Of the 5,814 women, 1,280 (22%) had adequate, 1,428 (24.6%) had inadequate, and 3,106 (53.4%) had excessive weight gain in the first and second trimesters. Women with inadequate early gestational weight gain were more likely to deliver an SGA neonate (adjusted odds ratio [aOR] 1.59, 95% CI 1.23-2.06) and less likely to deliver an LGA neonate (aOR 0.73, 95% CI 0.54-0.98), whereas those with excessive early gestational weight gain were less likely to deliver an SGA neonate (aOR 0.66, 95% CI 0.52-0.85) and more likely to deliver an LGA neonate (aOR 1.66, 95% CI 1.32-2.1). Higher weight gain in the third trimester was associated with increased risk for LGA birth weight, but third trimester weight gain was not related to SGA birth weight.

CONCLUSION

Early gestational weight gain is associated with birth weight category. Modifying weight gain in the third trimester may limit the risk for LGA birth weight, but higher weight gain in late gestation does not alter the association between inadequate early weight gain and the risk for SGA.

Effect of pregravid obesity on perinatal outcomes in singleton pregnancies following in vitro fertilization and the weight-loss goals to reduce the risks of poor pregnancy outcomes: A retrospective cohort study

OBJECTIVE

In the present study, we aimed to determine whether pregravid obesity independently predicts increased risks of perinatal complications following in vitro fertilization (IVF) and the weight loss goals to reduce the risk of poor pregnancy outcomes.

DESIGN

Retrospective cohort study.

POPULATION

All pregnancies after first the fresh IVF cycle from January 2014 to December 2016 in the Reproductive Center affiliated to Shandong University were reviewed. A total of 3,962 eligible singleton births were stratified into cohorts based on the body mass index (BMI) definitions of the Working Group on Obesity in China (WGOC).

MAIN OUTCOME MEASURES

Adverse perinatal outcomes.

RESULTS

Pregravid overweight and obesity were associated with increased risks of gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (HDP), including gestational hypertension (GH) and pre-eclampsia (PE), polyhydramnios, preterm premature rupture of the membranes (PPROM), placental abruption, preterm birth (PTB) <37 weeks, caesarean section (CS), fetal macrosomia, large for gestational age (LGA) >90th percentile, neonatal respiratory distress syndrome (NRDS), neonatal intensive care unit (NICU) admission and congenital anomalies as compared with the normal-weight group after adjustment of differences in age, parity, polycystic ovary syndrome (PCOS) and type of controlled ovarian hyperstimulation (COH). The increased risks of PPROM, NRDS and congenital anomalies were eliminated after adjustment of GDM development, whereas the increased risk of NRDS disappeared after adjustment of HDP. Placenta previa was not significantly different between the obese group and reference group (REF). Moreover, the rates of postpartum hemorrhage (PPH), PTB<32 weeks, small for gestational age (SGA) >90th percentile and perinatal mortality were also not significantly different between above-mentioned two groups. For obese women, a 10%-15% reduction in prepregnancy BMI was associated with significantly decreased risks of GH, CS and fetal macrosomia. For overweight women, just a 5% reduction in BMI could significantly reduce the risks of GDM, CS and fetal macrosomia.

CONCLUSIONS

Pregravid obesity could independently predict a higher risk of adverse pregnancy outcomes after adjustment of differences in maternal age, parity, PCOS, and type of COH in IVF pregnancies. The potential mechanism that obesity potentiated the risks of some poor perinantal outcomes might occur through the development of GDM and HDP. A 10%-15% reduction in pregravid BMI for obese women and a 5% reduction for overweight women were associated with a significant reduction of poor perinatal complications.

Role of neurotrophins in pregnancy, delivery and postpartum

Neurotrophins (NTs) are a family of polypeptides whose functions have been extensively studied in the past two decades. In particular, Nerve Growth Factor (NGF) and Brain-Derived Neurotrophic Factor (BDNF) play a major role in the development, nutrition and growth of the central and peripheral nervous system and in the pathogenesis of neurodegenerative, cardiometabolic and (auto)immune diseases. However, NGF and BDNF have subtle functions for follicular development, implantation, and placentation. This short narrative review summarizes the existing evidence, published between 2000 and 2019, about the role of NTs in many different conditions that might affect women during and after pregnancy such as preeclampsia, gestational diabetes, obesity, depression, anxiety, smoking and alcohol abuse. Literature suggests that the dysregulation of synthesis and release of NTs may lead to decisive effects on both maternal and fetal health. Some piece of evidences was found about a possible association between NGF/BDNF and breastfeeding. Additional studies on human models are necessary to further characterize the role of NTs in life-changing experiences like labor and delivery.

The Edmonton Obesity Staging System Predicts Mode of Delivery After Labour Induction

OBJECTIVE

This study sought to evaluate the use of the Edmonton Obesity Staging System (EOSS) in predicting cesarean delivery among term, nulliparous, singleton pregnancies in women with overweight or obesity who are undergoing an induction of labour.

METHODS

A prospective cohort study was performed in Edmonton, Alberta. Women undergoing an induction of labour at term were recruited to either a sample cohort, including women with a body mass index of ≥25 kg/m² at first antenatal visit, or a control cohort with a body mass index of 18.5 to 24.9 kg/m². Participating women provided a self-reported health history and consented to review of their medical records allowing allocation into EOSS categories. The primary outcome was the rate of cesarean delivery based on EOSS category. Secondary outcomes consisted of a summary score of adverse maternal, delivery, and neonatal events (Canadian Task Force Classification II-2).

RESULTS

Overall, 345 women were recruited, with a participation rate of 93.7%. The sample cohort consisted of 276 women with overweight or obesity, whereas the control cohort included 69 normal-weight women. The overall rate of cesarean delivery was 30.4% for the control cohort and 35.8%, 29.9%, 43.2%, and 90.5% for women assigned an EOSS category 0, 1, 2, and 3, respectively (P < 0.001). A summary score was not indicative of overall rate of adverse maternal, delivery, and neonatal events (P = 0.22).

CONCLUSION

The EOSS may help predict the chance of cesarean delivery in a high-risk group of nulliparous women with overweight or obesity who are undergoing an induction of labour at term.

Delivery room handling of the newborn

For newly born babies, especially those in need of intervention at birth, actions taken during the first minute after birth, the so-called "Golden Minute", can have important implications for long-term outcomes. Both delivery room handling, including identification of maternal and infant risk factors and provision of effective resuscitation interventions, and antenatal care decisions regarding antenatal steroid administration and mode of delivery, are important and can affect outcomes. Anticipating risk factors for neonates at high risk of requiring resuscitation can decrease time to resuscitation and improve the prognosis. Following a review of maternal and fetal risk factors affecting newborn resuscitation, we summarize the current recommendations for delivery room handling of the newborn. This includes recommendations and rationale for the use of delayed cord clamping and cord milking, heart rate assessment [including the use of electrocardiogram (ECG) electrodes in the delivery room], role of suctioning in newborn resuscitation, and the impact of various ventilatory modes. Oxygenation should be monitored by pulse oximetry. Effects of oxygen and surfactant on subsequent pulmonary outcomes, and recommendations for provisions of appropriate thermoregulatory support are discussed. Regular teaching of delivery room handling should be mandatory.

Country-Level Analysis of the Association between Maternal Obesity and Neonatal Mortality in 34 Sub-Saharan African Countries

Background

Prior work examining the association of maternal obesity and neonatal mortality indicate the presence of a positive relationship. However, regional evidence to provide insight on country-level heterogeneities within sub-Saharan Africa (SSA) with nationally representative datasets are non-existent.

Objective

We aimed to determine the relationship between maternal obesity and neonatal mortality at the country level in SSA countries. Moreover, we also estimate regional measures of association to complement previous findings.

Methods

Demographic and Health Survey (DHS) data from 34 SSA countries conducted from 2006-2016 were used for this study. After missing data (36.9% of cases) were addressed with multiple imputations, we identified a total of 175,860 women for the analysis. Complete case and multiply imputed datasets were analyzed individually with multilevel logistic regression models. Potential confounders adjusted for in the regression model included maternal age, level of educational attainment, area of residence, access to prenatal care, birth order and multiple birth (singleton vs twin birth). Regional and country-specific associations were computed, and unadjusted and adjusted odds ratios (ORs), along with the confidence intervals (CIs) were reported.

Findings

Of the total study population, 8,451 (7.6%) were obese. In the regional level analyses, maternal obesity was associated with 40% increased odds of neonatal deaths. This finding was consistent in subgroup analyses by urban and rural residence, and geographic region of residence in SSA. Additionally, obese women were more likely to report neonatal death in the first week of life (OR, days 0-1: 1.39, 95% CI 1.15-1.69; OR, days 2-6: 1.35, 95% CI 1.02-1.79). In the individual country analyses, majority of the countries studied had central estimates supporting elevated odds of neonatal mortality, but the confidence intervals were imprecise.

Conclusion

This study highlights the potential burden of neonatal mortality borne by obese women in SSA. There is, however, a need for longitudinal studies to confirm the results.

Neonatal and neurodevelopmental outcomes in preterm infants according to maternal body mass index: A prospective cohort study

OBJECTIVE

Maternal obesity is associated with an increase in maternal, foetal and neonatal morbidity and mortality. The aim of our study was to evaluate the relationships between maternal pre-pregnancy body mass index and (1) neonatal outcome in preterm infants, and (2) neurodevelopmental outcome at 2 years of corrected age.

METHOD

We conducted a single-centre cohort study. Infants born between 24+0 and 33+6 weeks of gestation between January 2009 and December 2013, hospitalised in the neonatal intensive care unit of Angers University Hospital, and with available data regarding maternal pre-pregnancy body mass index were eligible. Three groups were defined according to maternal body mass index: normal (n = 418), overweight (n = 136) and obese (n = 89). The primary outcome was neurodevelopment at 2 years of corrected age. Children with a non-optimal neuromotor and/or psychomotor assessment and/or a sensory disability were regarded as having a "non-optimal neurodevelopmental outcome". Neuromotor function was regarded as non-optimal when cerebral palsy was present or when the clinical examination revealed neurological signs of abnormal muscular tone. Psychomotor assessment was regarded as non-optimal if the revised Brunet-Lézine test was < 85 or when the overall score in the parental Ages and Stages Questionnaire (ASQ) was < 185. Finally, sensory disabilities such as blindness and children who required a hearing aid were taken into account. The secondary outcome was the composite criteria of neonatal complications. Multivariable analysis included the following variables: mother's age, gestational age, smoking during pregnancy, magnesium sulphate and steroid treatment during pregnancy, twin status, gender, socioeconomic status and social security benefits for those with low incomes.

RESULTS

The study population was composed of 643 preterm infants. Among them, 520 were assessed at 2 years. There was no difference in the proportion of infants with non-optimal neurodevelopmental outcomes between the three groups (16.6% for obese, 13.5% for overweight, 16.9% for normal body mass index mothers; p = 0.73). According to multivariable analysis, being born from an overweight or obese mother was not associated with an increased risk of non-optimal neuro-development at 2 years (adjusted OR = 0.84 [0.40-1.76] for obese, adjusted OR = 0.83 [0.43-1.59] for overweight mothers). There was no difference in the proportion of preterm infants with a non-optimal composite criterion of neonatal complications between the three groups. In the multivariable analysis, being born from an overweight or obese mother was not associated with an increased risk of non-optimal neonatal outcomes (adjusted OR = 0.95 [0.49-1.83] for obese, adjusted OR = 1.18 [0.69-2.01] for overweight mothers).

CONCLUSION

In this large prospective cohort of preterm infants born before 34 weeks of gestation, we found no relationship between maternal body mass index and neurodevelopmental outcomes at 2 years of corrected age and no relationship between maternal body mass index and neonatal outcomes. Other prematurity-related factors may be more relevant for neurodevelopmental outcome than the mother's pre-pregnancy BMI.

Potentially modifiable predictors of adverse neonatal and maternal outcomes in pregnancies with gestational diabetes mellitus: can they help for future risk stratification and risk-adapted patient care?

BACKGROUND

Gestational diabetes mellitus (GDM) exposes mothers and their offspring to short and long-term complications. The objective of this study was to identify the importance of potentially modifiable predictors of adverse outcomes in pregnancies with GDM. We also aimed to assess the relationship between maternal predictors and pregnancy outcomes depending on HbA1c values and to provide a risk stratification for adverse pregnancy outcomes according to the prepregnancy BMI (Body mass index) and HbA1c at the 1st booking.

METHODS

This prospective study included 576 patients with GDM. Predictors were prepregnancy BMI, gestational weight gain (GWG), excessive weight gain, fasting, 1 and 2-h glucose values after the 75 g oral glucose challenge test (oGTT), HbA1c at the 1st GDM booking and at the end of pregnancy and maternal treatment requirement. Maternal and neonatal outcomes such as cesarean section, macrosomia, large and small for gestational age (LGA, SGA), neonatal hypoglycemia, prematurity, hospitalization in the neonatal unit and Apgar score at 5 min < 7 were evaluated. Univariate and multivariate regression analyses and probability analyses were performed.

RESULTS

One-hour glucose after oGTT and prepregnancy BMI were correlated with cesarean section. GWG and HbA1c at the end pregnancy were associated with macrosomia and LGA, while prepregnancy BMI was inversely associated with SGA. The requirement for maternal treatment was correlated with neonatal hypoglycemia, and HbA1c at the end of pregnancy with prematurity (all p < 0.05). The correlations between predictors and pregnancy complications were exclusively observed when HbA1c was ≥5.5% (37 mmol/mol). In women with prepregnancy BMI ≥ 25 kg/m2 and HbA1c ≥ 5.5% (37 mmol/mol) at the 1st booking, the risk for cesarean section and LGA was nearly doubled compared to women with BMI with < 25 kg/m2 and HbA1c <  5.5% (37 mmol/mol).

CONCLUSIONS

Prepregnancy BMI, GWG, maternal treatment requirement and HbA1c at the end of pregnancy can predict adverse pregnancy outcomes in women with GDM, particularly when HbA1c is ≥5.5% (37 mmol/mol). Stratification based on prepregnancy BMI and HbA1c at the 1st booking may allow for future risk-adapted care in these patients.

Association between gestational weight gain and severe adverse birth outcomes in Washington State, US: A population-based retrospective cohort study, 2004-2013

BACKGROUND

Suboptimal weight gain during pregnancy is a potentially modifiable risk factor. We aimed to investigate the association between suboptimal gestational weight gain and severe adverse birth outcomes by pre-pregnancy body mass index (BMI) categories, including obesity class I to III.

METHODS AND FINDINGS

We conducted a population-based study of pregnant women with singleton hospital births in Washington State, US, between 2004 and 2013. Optimal, low, and excess weight gain in each BMI category was calculated based on weight gain by gestational age as recommended by the American College of Obstetricians and Gynecologists and the Institute of Medicine. Primary composite outcomes were (1) maternal death and/or severe maternal morbidity (SMM) and (2) perinatal death and/or severe neonatal morbidity. Logistic regression was used to obtain adjusted odds ratios (AORs) and 95% confidence intervals. Overall, 722,839 women with information on pre-pregnancy BMI were included. Of these, 3.1% of women were underweight, 48.1% had normal pre-pregnancy BMI, 25.8% were overweight, and 23.0% were obese. Only 31.5% of women achieved optimal gestational weight gain. Women who had low weight gain were more likely to be African American and have Medicaid health insurance, while women with excess weight gain were more likely to be non-Hispanic white and younger than women with optimal weight gain in each pre-pregnancy BMI category. Compared with women who had optimal weight gain, those with low gestational weight gain had a higher rate of maternal death, 7.97 versus 2.63 per 100,000 (p = 0.027). In addition, low weight gain was associated with the composite adverse maternal outcome (death/SMM) in women with normal pre-pregnancy BMI and in overweight women (AOR 1.12, 95% CI 1.04-1.21, p = 0.004, and AOR 1.17, 95% CI 1.04-1.32, p = 0.009, respectively) compared to women in the same pre-pregnancy BMI category who had optimal weight gain. Similarly, excess gestational weight gain was associated with increased rates of death/SMM among women with normal pre-pregnancy BMI (AOR 1.20, 95% CI 1.12-1.28, p < 0.001) and obese women (AOR 1.12, 95% CI 1.01-1.23, p = 0.019). Low gestational weight gain was associated with perinatal death and severe neonatal morbidity regardless of pre-pregnancy BMI, including obesity classes I, II, and III, while excess weight gain was associated with severe neonatal morbidity only in women who were underweight or had normal BMI prior to pregnancy. Study limitations include the ascertainment of pre-pregnancy BMI using self-report, and lack of data availability for the most recent years.

CONCLUSIONS

In this study, we found that most women do not achieve optimal weight gain during pregnancy. Low weight gain was associated with increased risk of severe adverse birth outcomes, and in particular with maternal death and perinatal death. Excess gestational weight gain was associated with severe adverse birth outcomes, except for women who were overweight prior to pregnancy. Weight gain recommendations for this group may need to be reassessed. It is important to counsel women during pregnancy about specific risks associated with both low and excess weight gain.

Maternal Overweight, Inflammation and Neurological Consequences for the Preterm Child: Results of the ELGAN Study

Maternal overweight and obesity are prenatal risk factors for obstetrical complications, preterm birth, neonatal morbidity as well as cognitive and behavioural developmental disorders in children. Paediatric morbidity and mortality as well as child development disorders are significantly associated with maternal obesity. Particularly in the neurodevelopmental and psychiatric area, it is becoming increasingly clear that, in children of mothers with an increased body mass index (BMI), there is a high correlation with childhood cognitive disabilities, attention disorders, and diseases on the autistic spectrum. The ELGAN (Extremely Low Gestational Age Newborn) study is a multicentre study which has been supported since 2000 by the National Institutes of Health (NIH) and whose objective is to research predictors for neonatal brain damage and neurological-cognitive sequelae in premature infants. The areas of focus are the connection between maternal overweight and obesity and pregnancy complications, APGAR scores and systemic inflammatory markers. In this overview, our aim is to summarise the work in this area and discuss it critically on the basis of current literature. We will examine the hypothesis whether maternal overweight and obesity in terms of a chronic inflammatory state is associated with neonatal inflammation which in turn is associated with an unfavourable development prognosis.

A new customised placental weight standard redefines the relationship between maternal obesity and extremes of placental size and is more closely associated with pregnancy complications than an existing population standard

Placental weight is a valuable indicator of its function, predicting both pregnancy outcome and lifelong health. Population-based centile charts of weight-for-gestational-age and parity are useful for identifying extremes of placental weight but fail to consider maternal size. To address this deficit, a multiple regression model was fitted to derive coefficients for predicting normal placental weight using records from healthy pregnancies of nulliparous/multiparous women of differing height and weight (n = 107,170 deliveries, 37-43 weeks gestation). The difference between actual and predicted placental weight generated a z-score/individual centile for the entire cohort including women with pregnancy complications (n = 121,591). The association between maternal BMI and placental weight extremes defined by the new customised versus population-based standard was investigated by logistic regression, as was the association between low placental weight and pregnancy complications. Underweight women had a greater risk of low placental weight [<10thcentile, OR 1.84 (95% CI 1.66, 2.05)] and obese women had a greater risk of high placental weight [>90th centile, OR 1.98 (95% CI 1.88, 2.10)] using a population standard. After customisation, the risk of high placental weight in obese/morbidly obese women was attenuated [OR 1.17 (95% CI 1.09, 1.25)]/no longer significant, while their risk of low placental weight was 59%-129% higher (P < 0.001). The customised placental weight standard was more closely associated with stillbirth, hypertensive disease, placental abruption and neonatal death than the population standard. Our customised placental weight standard reveals higher risk of relative placental growth restriction leading to lower than expected birthweights in obese women, and a stronger association between low placental weight and pregnancy complications generally. Further, it provides an alternative tool for defining placental weight extremes with implications for the placental programming of chronic disease.

Factors associated with stillbirth in women with diabetes

AIMS/HYPOTHESIS

Stillbirth risk is increased in pregnancy complicated by diabetes. Fear of stillbirth has major influence on obstetric management, particularly timing of delivery. We analysed population-level data from Scotland to describe timing of stillbirths in women with diabetes and associated risk factors.

METHODS

A retrospective cohort of singleton deliveries to mothers with type 1 (n = 3778) and type 2 diabetes (n = 1614) from 1 April 1998 to 30 June 2016 was analysed using linked routine care datasets. Maternal and fetal characteristics, HbA_1c data and delivery timing were compared between stillborn and liveborn groups.

RESULTS

Stillbirth rates were 16.1 (95% CI 12.4, 20.8) and 22.9 (95% CI 16.4, 31.8) per 1000 births in women with type 1 (n = 61) and type 2 diabetes (n = 37), respectively. In women with type 1 diabetes, higher HbA_1c before pregnancy (OR 1.03 [95% CI 1.01, 1.04]; p = 0.0003) and in later pregnancy (OR 1.06 [95% CI 1.04, 1.08]; p < 0.0001) were associated with stillbirth, while in women with type 2 diabetes, higher maternal BMI (OR 1.07 [95% CI 1.01, 1.14]; p = 0.02) and pre-pregnancy HbA_1c (OR 1.02 [95% CI 1.00, 1.04]; p = 0.016) were associated with stillbirth. Risk was highest in infants with birthweights <10th centile (sixfold higher born to women with type 1 diabetes [n = 5 stillbirths, 67 livebirths]; threefold higher for women with type 2 diabetes [n = 4 stillbirths, 78 livebirths]) compared with those in the 10th-90th centile (n = 20 stillbirths, 1685 livebirths). Risk was twofold higher in infants with birthweights >95th centile born to women with type 2 diabetes (n = 15 stillbirths, 402 livebirths). A high proportion of stillborn infants were male among mothers with type 2 diabetes (81.1% vs 50.5% livebirths, p = 0.0002). A third of stillbirths occurred at term, with highest rates in the 38th week (7.0 [95% CI 3.7, 12.9] per 1000 ongoing pregnancies) among mothers with type 1 diabetes and in the 39th week (9.3 [95% CI 2.4, 29.2]) for type 2 diabetes.

CONCLUSIONS/INTERPRETATION

Maternal blood glucose levels and BMI are important modifiable risk factors for stillbirth in diabetes. Babies at extremes of weight centiles are at most risk. Many stillbirths occur at term and could potentially be prevented by change in routine care and delivery policies.

The Risks Associated With Obesity in Pregnancy

BACKGROUND

Approximately one-third of all women of childbearing age are overweight or obese. For these women, pregnancy is associated with increased risks for both mother and child.

METHODS

This review is based on pertinent publications retrieved by a selective search of PubMed, with special attention to current population-based cohort studies, systematic reviews, meta-analyses, and controlled trials.

RESULTS

Obesity in pregnancy is associated with unfavorable clinical outcomes for both mother and child. Many of the risks have been found to depend linearly on the body-mass index (BMI). The probability of conception declines linearly, starting from a BMI of 29 kg/m2, by 4% for each additional 1 kg/m2 of BMI (hazard ratio 0.96, 95% confidence interval: [0.91; 0.99]). A 10% increase of pregravid BMI increases the relative risk of gestational diabetes and that of preeclampsia by approximately 10% each. A 5 kg/m2 increase of BMI elevates the relative risk of intrauterine death to 1.24 [1.18; 1.30]. An estimated 11% of all neonatal deaths can be attributed to the consequences of maternal overweight and obesity. Nonetheless, in most randomized controlled trials, nutritional and lifestyle interventions did not bring about any clinically relevant reduction in the incidence of gestational diabetes and fetal macrosomia.

CONCLUSION

The risks associated with obesity in pregnancy cannot necessarily be influenced by intervention. Preventive measures aimed at normalizing body weight before a woman becomes pregnant are, therefore, all the more important.

Maternal Obesity and Offspring Long-Term Infectious Morbidity

Obesity is a leading cause of morbidity world-wide. Maternal obesity is associated with adverse perinatal outcomes. Furthermore, Obesity has been associated with increased susceptibility to infections. The purpose of this study was to evaluate long-term pediatric infectious morbidity of children born to obese mothers. This population-based cohort analysis compared deliveries of obese (maternal pre-pregnancy BMI ≥ 30 kg/m²) and non-obese patients at a single tertiary medical center. Hospitalizations of the offspring up to the age of 18 years involving infectious morbidities were evaluated according to a predefined set of ICD-9 codes. A Kaplan–Meier survival curve was used to compare cumulative hospitalization incidence between the groups and Cox proportional hazards model was used to control for possible confounders. 249,840 deliveries were included. Of them, 3399 were children of obese mothers. Hospitalizations involving infectious morbidity were significantly more common in children born to obese mothers compared with non-obese patients (12.5% vs. 11.0%, p < 0.01). The Kaplan–Meier survival curve demonstrated a significantly higher cumulative incidence of infectious-related hospitalizations in the obese group (log rank p = 0.03). Using the Cox regression model, maternal obesity was found to be an independent risk factor for long-term infectious morbidity of the offspring (adjusted HR = 1.125, 95% CI 1.021–1.238, p = 0.017).

Impact of pregravid obesity on maternal and fetal immunity: Fertile grounds for reprogramming

Maternal pregravid obesity results in several adverse health outcomes during pregnancy, including increased risk of gestational diabetes, preeclampsia, placental abruption, and complications at delivery. Additionally, pregravid obesity and in utero exposure to high fat diet have been shown to have detrimental effects on fetal programming, predisposing the offspring to adverse cardiometabolic, endocrine, and neurodevelopmental outcomes. More recently, a deeper appreciation for the modulation of offspring immunity and infectious disease-related outcomes by maternal pregravid obesity has emerged. This review will describe currently available animal models for studying the impact of maternal pregravid obesity on fetal immunity and review the data from clinical and animal model studies. We also examine the burden of pregravid obesity on the maternal-fetal interface and the link between placental and systemic inflammation. Finally, we discuss future studies needed to identify key mechanistic underpinnings that link maternal inflammatory changes and fetal cellular reprogramming events.

Effect of maternal obesity on pregnancy outcomes in women delivering singleton babies: a historical cohort study

Background Obesity in pregnancy is increasing worldwide, reaching epidemic proportions in many countries and frequently creating challenges for obstetricians. We conducted this study to assess the effects of maternal obesity on maternal and perinatal outcomes. Methods A historical cohort study was performed on 16,609 women who delivered singleton babies in a 5-year period (2013-2017). Data were retrieved from the Cruces Perinatal Database (CPD) and only women whose prepregnancy body mass index (BMI) was known were included. Women were categorized according to the World Health Organization (WHO) classification: normal weight (BMI 20-24.9 kg/m2) and obesity (BMI ≥ 30 kg/m2). Obstetric, perinatal and neonatal outcomes were compared, and adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were calculated using the normal-weight group as the reference. Results Compared to women of normal weight (n = 9778), obese women (n = 2207) had a higher risk of preeclampsia (aOR 2.199, 95% CI: 1.46-3.29), rectovaginal group B streptococcus colonization (aOR 1.299, 95% CI: 1.14-1.47), induction of labor (aOR 1.593, 95% CI: 1.44-1.75), cesarean section (aOR 2.755, 95% CI: 2.46-3.08), cesarean section in women with a history of cesarean delivery (aOR 1.409, 95% CI: 1.03-1.92), fetal weight ≥4000 g (aOR 2.090, 95% CI: 1.803-2.422) and admission to the neonatal intensive care unit (NICU) (aOR 1.341, 95% CI: 1.12-1.59). No association was found with preterm birth (aOR 0.936, 95% CI: 0.77-1.13), stillbirth (aOR 0.921, 95% CI: 0.41-2.02) or neonatal mortality (aOR 2.205, 95% CI: 0.86-5.62). Conclusion Maternal obesity is associated with a higher risk of adverse pregnancy and perinatal outcomes. Pregnancy in this population of women should be considered and managed as high risk.

Health outcomes for Massachusetts infants after fresh versus frozen embryo transfer

OBJECTIVE

To compare neonatal health outcomes after fresh versus frozen ET (FET).

DESIGN

Retrospective analysis of a population-based database of linked clinically assisted reproductive technology (ART) data with state vital records. Multivariable logistic regression was used to model the association between deliveries from fresh versus FET and adverse health outcomes, controlling for maternal characteristics.

SETTING

Not applicable.

PATIENT(S)

Live-born singleton infants born to Massachusetts women who conceived by fresh or FET after ART using autologous oocytes between July 1, 2004, and December 31, 2013.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Preterm birth, low birth weight, neonatal mortality, birth defects, organ system conditions.

RESULT(S)

Compared with infants conceived from fresh embryos, those born to mothers who underwent FET were less likely to be small for gestational age (adjusted odds ratio [AOR] = 0.56; 95% confidence interval [CI], 0.44-0.70) and low birth weight (AOR = 0.72; 95% CI, 0.59-0.88) but more likely to be large for gestational age (AOR = 1.47; 95% CI, 1.26-1.70) and to experience greater odds of infectious disease (AOR = 1.46; 95% CI, 1.03-2.06), respiratory (AOR = 1.23; 95% CI, 1.07-1.41), and neurologic (AOR = 1.32; 95% CI, 1.04-1.68) conditions. There were no statistically significant differences in preterm birth, neonatal mortality, birth defects, cardiovascular, hematologic, and gastrointestinal/feeding conditions, and for infants ≥ 35 weeks, no statistically significant differences in prolonged hospital stay (>3 days for vaginal delivery, >5 days for cesarean).

CONCLUSION(S)

Compared with infants conceived from fresh ET, those born by FET have higher birth weight but increased odds of infectious disease, hematologic, respiratory, and neurologic abnormalities. These risks should be considered when making decisions on fresh versus FET.

The Effects of Overweight and Obesity on Assisted Reproduction Technology Outcomes

The aim of the present study was to assess the impact of professional nutrition assistance on assisted reproduction technology (ART) outcomes in overweight or obese patients with polycystic ovarian syndrome (PCOS). The study represents a retrospective analysis of fertilization rates, embryo quality and gestations after ART in seven PCOS patients, five obese and two overweight. The women attended a private Fertility Center in Brazil between the years 2010 and 2016. Out of the seven patients, the three that reached a successful gestation were the ones that underwent comprehensive lifestyle changes, taking care of their diet for a more prolonged period of time and reached an ideal weight loss during the nutrition counseling period.

Intergenerational Effects of Health Issues Among Women of Childbearing Age: a Review of the Recent Literature

PURPOSE OF REVIEW

This review summarizes the latest scientific evidence, primarily from systematic reviews/meta-analyses and large cohort studies, on the impact of health issues among women of childbearing age and their effect on their offspring during pregnancy and from birth to adulthood.

RECENT FINDINGS

Women of childbearing age with overweight/obesity, diabetes, and hypertension prior to pregnancy are at increased risk for adverse outcomes during pregnancy, such as excessive gestational weight gain, gestational diabetes mellitus, and hypertensive disorders of pregnancy. These adverse outcomes could complicate delivery and put their offspring at risk of developing overweight/obesity, diabetes, and hypertension (i.e., intergenerational transmission of health issues). Interventions should target women of childbearing age, especially those who wish to conceive, in order to possibly stop the transmission of women's health issues to the offspring and favor a healthy pregnancy from the start. This could be one of the best strategies to promote both maternal and child health.

Influence of metabolic syndrome on female fertility and in vitro fertilization outcomes in PCOS women

OBJECTIVE

With a high incidence of insulin resistance, central obesity and dyslipidemia, women with polycystic ovary syndrome are susceptible to metabolic syndrome (MetS). Our objective was to explore whether metabolic syndrome had an effect on overall female fertility and in vitro fertilization outcomes in infertile women with polycystic ovary syndrome.

STUDY DESIGN

This was a secondary analysis of a multicenter randomized trial in 1508 women with polycystic ovary syndrome, which was originally designed to compare the live birth rate after fresh-embryo transfer vs frozen embryo transfer (Frefro-PCOS). At baseline, metabolic parameters, including body mass index, waist and hip circumference, blood pressure, lipid profile, fasting, and 2 hour glucose and insulin levels after a 75 g oral glucose tolerance test were measured. All subjects were divided into a metabolic syndrome group (metabolic syndrome) and absence of metabolic syndrome group (nonmetabolic syndrome) according to diagnostic criteria. Descriptive statistics and logistic regression models tested the association between metabolic syndrome and overall fertility and in vitro fertilization cycle stimulation characteristics and clinical outcomes.

RESULTS

Metabolic syndrome was identified in 410 of 1508 infertile women with polycystic ovary syndrome (27.2%). Patients with metabolic syndrome had longer infertility duration (4.0 ± 2.2 vs 3.7 ± 2.2, P = .004) compared with those without metabolic syndrome. During ovarian stimulation, those with metabolic syndrome required significantly higher and longer doses of gonadotropin and had lower peak estradiol level, fewer retrieved oocytes, available embryos, a lower oocyte utilization rate, and ovarian hyperstimulation syndrome than those with nonmetabolic syndrome. The cumulative live birth rate did not show a significant between-group difference (57.8% vs 62.2%, P = .119). Multivariate logistic regression analysis adjusted for age, duration of infertility, body mass index, thyroid-stimulating hormone, metabolic syndrome group, homeostatic model assessment of insulin resistance, metformin utilization, number of available embryos, and embryos transferred showed that the number of embryos transferred and the number of available embryos were positively but metabolic syndrome negatively associated with the cumulative live birth rate (odds ratio, 2.18, 1.10, and 0.70, respectively, P < .05).

CONCLUSION

Women with polycystic ovary syndrome with metabolic syndrome have a negative impact from female fecundity, and this suggests an adverse effect on in vitro fertilization cycle stimulation characteristics and clinical outcomes.

The double burden of under- and overnutrition among Bangladeshi women: Socioeconomic and community-level inequalities

BACKGROUND

The prevalence of overweightness in Bangladesh is increasing, while underweightness also continues to persist. A better understanding of the patterns and socioeconomic risk factors of both conditions, particularly among women, is critical in order to promote the development of interventions to improve maternal health in Bangladesh. This study therefore sought to assess the patterns of under- and overweightness between 2004 and 2014 and to examine the predictors of individual and community-level inequalities of under- and overnutrition in Bangladesh.

METHODS

Cross-sectional data of 10, 431, and 16,478 ever-married nonpregnant women aged between 15 and 49 years who did not give birth in the two months preceding the survey were extracted from the 2004 and 2014 Bangladesh Demographic and Health Surveys, respectively. Body mass index was used to measure weight status, and underweightness, at-risk for overweightness, overweightness, and obesity were the main outcome variables. Patterns of nutritional change over time was examined by considering the annual average rate of change. Multilevel multinomial logistic regression and quantile regression were used to identify the inequalities.

RESULTS

In 2014, the age-adjusted prevalence values of underweightness, at-risk for overweightness, overweightness, and obesity were 19.7%, 14.9%, 18.1% and 4.0%, respectively. A higher average annual rate of reduction of underweightness was found among wealthier, highly educated, and wealthier community-living women, while a rate of increase of overweightness was found among poorer, uneducated, and poor community-living women. Individual and community-level inequalities of malnutrition were observed among these populations. In comparison with women living in low wealth communities, women from wealthier communities were at an increased risk of being at-risk for overweightness [adjusted odds ratio (AOR): 1.53, 95% confidence interval (CI): 1.23-1.91], overweight (AOR: 1.60, 95% CI: 1.27-2.00), and obese (AOR: 2.12, 95% CI: 1.42-3.18).

CONCLUSIONS

This study suggests the coexistence of a double burden of under- and overnutrition in Bangladesh and that the prevalence of overweightness surpasses that of underweightness. The burdens of under- and overnutrition are strongly associated with women's individual socioeconomic positions and the nature of the community in which they live.

Association between parental body mass index and autism spectrum disorder: a systematic review and meta-analysis

Studies have examined the association between parental body mass index (BMI) and autism spectrum disorder (ASD) in offspring, with inconsistent results, especially regarding maternal obesity, overweight and underweight. Cochrane Library, EMBASE, PubMed and PsycINFO databases were searched up to March 2018 for relevant observational studies with no language restriction. Our literature search identified 13 eligible studies for meta-analysis (involving 943,293 children and 30,337 cases). For maternal BMI (13 studies), both maternal obesity [OR 1.41 (95% CI 1.19-1.67)] and maternal overweight [OR 1.16 (95% CI 1.05-1.27)] were significantly associated with ASD, while maternal underweight was not associated with ASD [OR 1.08 (95% CI 0.98-1.20)]. For paternal BMI (three studies), no association was found (paternal obesity: OR 1.28, 95% CI 0.94-1.74; overweight: OR 1.07, 95% CI 0.99-1.15; underweight: OR 1.12, 95% CI 0.87-1.44). Pooled estimates were robust in sensitivity analysis and subgroup analyses. Publication bias may exist for studies assessing maternal BMI and ASD risk, but the filled estimates were not altered. Relative to normal weight, maternal obesity and overweight were significantly associated with increased ASD risk, while maternal underweight was not associated with ASD. Although no association between paternal BMI and ASD was found, current evidence is limited (three studies). Future studies are warranted to address more confounding factors and to identify potential mediators of the association, but pre-pregnancy weight control is suggested.

Comparison of Parametric and Nonparametric Estimators for the Association Between Incident Prepregnancy Obesity and Stillbirth in a Population-Based Cohort Study

While prepregnancy obesity increases risk of stillbirth, few studies have evaluated the role of newly developed obesity independent of long-standing obesity. Additionally, researchers have relied almost exclusively on parametric models, which require correct specification of an unknown function for consistent estimation. We estimated the association between incident obesity and stillbirth in a cohort constructed from linked birth and death records in Pennsylvania (2003-2013). Incident obesity was defined as body mass index (weight (kg)/height (m)2) greater than or equal to 30. We used parametric G-computation, semiparametric inverse-probability weighting, and parametric/nonparametric targeted minimum loss-based estimation (TMLE) to estimate the association between incident prepregnancy obesity and stillbirth. Compared with pregnancies from women who stayed nonobese, women who became obese prior to their next pregnancy were estimated to have 2.0 (95% confidence interval (CI): 0.5, 3.5) more stillbirths per 1,000 pregnancies using parametric G-computation. However, despite well-behaved stabilized inverse probability weights, risk differences estimated from inverse-probability weighting, nonparametric TMLE, and parametric TMLE represented 6.9 (95% CI: 3.7, 10.0), 0.4 (95% CI: 0.1, 0.7), and 2.9 (95% CI: 1.5, 4.2) excess stillbirths per 1,000 pregnancies, respectively. These results, particularly those derived from nonparametric TMLE, were highly sensitive to covariates included in the propensity score models. Our results suggest that caution is warranted when using nonparametric estimators to quantify exposure effects.

Adverse Maternal Metabolic Intrauterine Environment and Placental Epigenetics: Implications for Fetal Metabolic Programming

PURPOSE OF REVIEW

Herein, we summarize existent epidemiological studies relating adverse maternal metabolic environments of maternal obesity and gestational diabetes and placental DNA methylation.

RECENT FINDINGS

Multiple studies have evaluated associations between intrauterine exposure to gestational diabetes and/or maternal glucose levels and DNA methylation at candidate metabolic genes as well as in epigenome-wide studies. Some of the genomic regions more consistently associated include lipid-related genes (LPL and PPARGC1A), the major histocompatibility complex (MHC), and imprinted genes. Studies solely focused on maternal obesity influences on the placental epigenome are scarce. Understanding the placental mechanisms involved in fetal metabolic programming could lead to discovery of placental biomarkers at birth that predict later-life metabolic risk. Moving forward is important to standardize methods utilized in epigenetics research; consistent methodology can help interpret disparate findings. Larger studies with longitudinal follow-up are needed to address future challenges in fetal programming research.

Association of Maternal Obesity in Early Pregnancy with Adverse Pregnancy Outcomes: A Chinese Prospective Cohort Analysis

OBJECTIVE

This study aimed to examine the associations of maternal obesity in early pregnancy with adverse pregnancy outcomes.

METHODS

A prospective cohort analysis was performed among 18,481 Chinese nulliparous women, using data from a 2006 to 2009 trial of prenatal micronutrient supplementation. Obesity was defined as BMI ≥ 27.5 kg/m² . Interested outcomes included fetal loss (spontaneous abortion plus stillbirth), infant death, total mortality, and preterm and birth weight outcomes.

RESULTS

Compared with normal weight, obesity was associated with total mortality (adjusted relative risks [ARR] 1.34; 95% CI: 1.03-1.74) and fetal loss (ARR 1.51; 95% CI: 1.15-1.99) but not with infant death (ARR 0.53; 95% CI: 0.20-1.46). Further analyses showed that obesity was particularly associated with spontaneous abortion (ARR 1.51; 95% CI: 1.13-2.02) rather than stillbirth (ARR 1.52; 95% CI: 0.65-3.57). Moreover, obesity was associated with preterm birth (ARR 1.59; 95% CI: 1.25-2.02), macrosomia (ARR 3.71, 95% CI: 3.01-4.59), and large for gestational age (ARR 2.93; 95% CI: 2.49-3.47).

CONCLUSIONS

Maternal obesity in early pregnancy is associated with various adverse pregnancy outcomes in Chinese nulliparous women, suggesting the importance of an appropriate weight before and during pregnancy.

Association of Gestational Weight Gain With Adverse Maternal and Infant Outcomes

Importance

Both low and high gestational weight gain have been associated with adverse maternal and infant outcomes, but optimal gestational weight gain remains uncertain and not well defined for all prepregnancy weight ranges.

Objectives

To examine the association of ranges of gestational weight gain with risk of adverse maternal and infant outcomes and estimate optimal gestational weight gain ranges across prepregnancy body mass index categories.

Design, Setting, and Participants

Individual participant-level meta-analysis using data from 196 670 participants within 25 cohort studies from Europe and North America (main study sample). Optimal gestational weight gain ranges were estimated for each prepregnancy body mass index (BMI) category by selecting the range of gestational weight gain that was associated with lower risk for any adverse outcome. Individual participant-level data from 3505 participants within 4 separate hospital-based cohorts were used as a validation sample. Data were collected between 1989 and 2015. The final date of follow-up was December 2015.

Exposures

Gestational weight gain.

Main Outcomes and Measures

The main outcome termed any adverse outcome was defined as the presence of 1 or more of the following outcomes: preeclampsia, gestational hypertension, gestational diabetes, cesarean delivery, preterm birth, and small or large size for gestational age at birth.

Results

Of the 196 670 women (median age, 30.0 years [quartile 1 and 3, 27.0 and 33.0 years] and 40 937 were white) included in the main sample, 7809 (4.0%) were categorized at baseline as underweight (BMI <18.5); 133 788 (68.0%), normal weight (BMI, 18.5-24.9); 38 828 (19.7%), overweight (BMI, 25.0-29.9); 11 992 (6.1%), obesity grade 1 (BMI, 30.0-34.9); 3284 (1.7%), obesity grade 2 (BMI, 35.0-39.9); and 969 (0.5%), obesity grade 3 (BMI, ≥40.0). Overall, any adverse outcome occurred in 37.2% (n = 73 161) of women, ranging from 34.7% (2706 of 7809) among women categorized as underweight to 61.1% (592 of 969) among women categorized as obesity grade 3. Optimal gestational weight gain ranges were 14.0 kg to less than 16.0 kg for women categorized as underweight; 10.0 kg to less than 18.0 kg for normal weight; 2.0 kg to less than 16.0 kg for overweight; 2.0 kg to less than 6.0 kg for obesity grade 1; weight loss or gain of 0 kg to less than 4.0 kg for obesity grade 2; and weight gain of 0 kg to less than 6.0 kg for obesity grade 3. These gestational weight gain ranges were associated with low to moderate discrimination between those with and those without adverse outcomes (range for area under the receiver operating characteristic curve, 0.55-0.76). Results for discriminative performance in the validation sample were similar to the corresponding results in the main study sample (range for area under the receiver operating characteristic curve, 0.51-0.79).

Conclusions and Relevance

In this meta-analysis of pooled individual participant data from 25 cohort studies, the risk for adverse maternal and infant outcomes varied by gestational weight gain and across the range of prepregnancy weights. The estimates of optimal gestational weight gain may inform prenatal counseling; however, the optimal gestational weight gain ranges had limited predictive value for the outcomes assessed.

Maternal obesity in pregnancy impacts offspring cardiometabolic health: Systematic review and meta-analysis of animal studies

Obesity before and during pregnancy leads to reduced offspring cardiometabolic health. Here, we systematically reviewed animal experimental evidence of maternal obesity before and during pregnancy and offspring anthropometry and cardiometabolic health. We systematically searched Embase and Medline from inception until January 2018. Eligible publications compared offspring of mothers with obesity to mothers with a normal weight. We performed meta-analyses and subgroup analyses. We also examined methodological quality and publication bias. We screened 2543 publications and included 145 publications (N = 21 048 animals, five species). Essential methodological details were not reported in the majority of studies. We found evidence of publication bias for birth weight. Offspring of mothers with obesity had higher body weight (standardized mean difference (SMD) 0.76 [95% CI 0.60;0.93]), fat percentage (0.99 [0.64;1.35]), systolic blood pressure (1.33 [0.75;1.91]), triglycerides (0.64 [0.42;0.86], total cholesterol (0.46 [0.18;0.73]), glucose level (0.43 [0.24;0.63]), and insulin level (0.81 [0.61;1.02]) than offspring of control mothers, but similar birth weight. Sex, age, or species did not influence the effect of maternal obesity on offspring's cardiometabolic health. Obesity before and during pregnancy reduces offspring cardiometabolic health in animals. Future intervention studies should investigate whether reducing obesity prior to conception could prevent these detrimental programming effects and improve cardiometabolic health of future generations.

A Co-expression Analysis of the Placental Transcriptome in Association With Maternal Pre-pregnancy BMI and Newborn Birth Weight

Maternal body mass index (BMI) before pregnancy is known to affect both fetal growth and later-life health of the newborn, yet the implicated molecular mechanisms remain largely unknown. As the master regulator of the fetal environment, the placenta is a valuable resource for the investigation of processes involved in the developmental programming of metabolic health. We conducted a genome-wide placental transcriptome study aiming at the identification of functional pathways representing the molecular link between maternal BMI and fetal growth. We used RNA microarray (Agilent 8 × 60 K), medical records, and questionnaire data from 183 mother-newborn pairs from the ENVIRONAGE birth cohort study (Flanders, Belgium). Using a weighted gene co-expression network analysis, we identified 17 correlated gene modules. Three of these modules were associated with both maternal pre-pregnancy BMI and newborn birth weight. A gene cluster enriched for genes involved in immune response and myeloid cell differentiation was positively associated with maternal BMI and negatively with low birth weight. Two other gene modules, upregulated in association with maternal BMI as well as birth weight, were involved in processes related to organ and tissue development, with blood vessel morphogenesis and extracellular matrix structure as top Gene Ontology terms. In line with this, erythrocyte-, angiogenesis-, and extracellular matrix-related genes were among the identified hub genes. The association between maternal BMI and newborn weight was significantly mediated by gene expression for 5 of the hub genes (FZD4, COL15A1, GPR124, COL6A1, and COL1A1). As some of the identified hub genes have been linked to obesity in adults, our observation in placental tissue suggests that biological processes may be affected from prenatal life onwards, thereby identifying new molecular processes linking maternal BMI and fetal metabolic programming.