Gestational weight gain and preterm birth in obese women: a systematic review and meta-analysis

Safety of low weight gain or weight loss in pregnancies with class 1, 2, and 3 obesity: a population-based cohort study

BACKGROUND

There are concerns that current gestational weight gain recommendations for women with obesity are too high and that guidelines should differ on the basis of severity of obesity. In this study we investigated the safety of gestational weight gain below current recommendations or weight loss in pregnancies with obesity, and evaluated whether separate guidelines are needed for different obesity classes.

METHODS

In this population-based cohort study, we used electronic medical records from the Stockholm-Gotland Perinatal Cohort study to identify pregnancies with obesity (early pregnancy BMI before 14 weeks' gestation ≥30 kg/m2) among singleton pregnancies that delivered between Jan 1, 2008, and Dec 31, 2015. The pregnancy records were linked with Swedish national health-care register data up to Dec 31, 2019. Gestational weight gain was calculated as the last measured weight before or at delivery minus early pregnancy weight (at <14 weeks' gestation), and standardised for gestational age into z-scores. We used Poisson regression to assess the association of gestational weight gain z-score with a composite outcome of: stillbirth, infant death, large for gestational age and small for gestational age at birth, preterm birth, unplanned caesarean delivery, gestational diabetes, pre-eclampsia, excess postpartum weight retention, and new-onset longer-term maternal cardiometabolic disease after pregnancy, weighted to account for event severity. We calculated rate ratios (RRs) for our composite adverse outcome along the weight gain z-score continuum, compared with a reference of the current lower limit for gestational weight gain recommended by the US Institute of Medicine (IOM; 5 kg at term). RRs were adjusted for confounding factors (maternal age, height, parity, early pregnancy BMI, early pregnancy smoking status, prepregnancy cardiovascular disease or diabetes, education, cohabitation status, and Nordic country of birth).

FINDINGS

Our cohort comprised 15 760 pregnancies with obesity, followed up for a median of 7·9 years (IQR 5·8-9·4). 11 667 (74·0%) pregnancies had class 1 obesity, 3160 (20·1%) had class 2 obesity, and 933 (5·9%) had class 3 obesity. Among these pregnancies, 1623 (13·9%), 786 (24·9%), and 310 (33·2%), respectively, had weight gain during pregnancy below the lower limit of the IOM recommendation (5 kg). In pregnancies with class 1 or 2 obesity, gestational weight gain values below the lower limit of the IOM recommendation or weight loss did not increase risk of the adverse composite outcome (eg, at weight gain z-score -2·4, corresponding to 0 kg at 40 weeks: adjusted RR 0·97 [95% CI 0·89-1·06] in obesity class 1 and 0·96 [0·86-1·08] in obesity class 2). In pregnancies with class 3 obesity, weight gain values below the IOM limit or weight loss were associated with reduced risk of the adverse composite outcome (eg, adjusted RR 0·81 [0·71-0·89] at weight gain z-score -2·4, or 0 kg).

INTERPRETATION

Our findings support calls to lower or remove the lower limit of current IOM recommendations for pregnant women with obesity, and suggest that separate guidelines for class 3 obesity might be warranted.

FUNDING

Karolinska Institutet and the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

Association of prepregnancy body mass index and gestational weight gain trajectory with adverse pregnancy outcomes-a prospective cohort study in Shanghai

OBJECTIVES

The objective was to investigate the associations of maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) trajectories with adverse pregnancy outcomes (APOs).

DESIGN

This was a prospective cohort study.

SETTING

This study was conducted in Shanghai Pudong New Area Health Care Hospital for Women and Children, Shanghai, China.

PRIMARY AND SECONDARY OUTCOME MEASURES

A cohort study involving a total of 2174 pregnant women was conducted. Each participant was followed to record weekly weight gain and pregnancy outcomes. The Institute of Medicine classification was used to categorise prepregnancy BMI, and four GWG trajectories were identified using a latent class growth model.

RESULTS

The adjusted ORs for the risks of large for gestational age (LGA), macrosomia, gestational diabetes mellitus (GDM) and hypertensive disorders of pregnancy (HDP) were significantly greater for women with prepregnancy overweight/obesity (OR=1.77, 2.13, 1.95 and 4.24; 95% CI 1.3 to 2.42, 1.32 to 3.46, 1.43 to 2.66 and 2.01 to 8.93, respectively) and lower for those who were underweight than for those with normal weight (excluding HDP) (OR=0.35, 0.27 and 0.59; 95% CI 0.22 to 0.53, 0.11 to 0.66 and 0.36 to 0.89, respectively). The risk of small for gestational age (SGA) and low birth weight (LBW) was significantly increased in the underweight group (OR=3.11, 2.20; 95% CI 1.63 to 5.92, 1.10 to 4.41; respectively) compared with the normal-weight group; however, the risk did not decrease in the overweight/obese group (p=0.942, 0.697, respectively). GWG was divided into four trajectories, accounting for 16.6%, 41.4%, 31.7% and 10.3% of the participants, respectively. After adjustment for confounding factors, the risk of LGA was 1.54 times greater for women in the slow GWG trajectory group than for those in the extremely slow GWG trajectory group (95% CI 1.07 to 2.21); the risk of SGA and LBW was 0.37 times and 0.46 times lower for women in the moderate GWG trajectory group and 0.14 times and 0.15 times lower for women in the rapid GWG trajectory group, respectively; the risk of macrosomia and LGA was 2.65 times and 2.70 times greater for women in the moderate GWG trajectory group and 3.53 times and 4.36 times greater for women in the rapid GWG trajectory group, respectively; and the women in the other three trajectory groups had a lower risk of GDM than did those in the extremely slow GWG trajectory group, but there was not much variation in the ORs. Notably, different GWG trajectories did not affect the risk of HDP.

CONCLUSIONS

As independent risk factors, excessively high and low prepregnancy BMI and GWG can increase the risk of APOs.

The Impact of Higher Than Recommended Gestational Weight Gain on Fetal Growth and Perinatal Risk Factors-The IOM Criteria Reconsidered

A too-high gestational weight gain, in combination with steadily increasing obesity rates among women of reproductive age, represents an enormous obstetrical problem, as obesity and high gestational weight gain are associated with enhanced fetal growth, low vital parameters, and increased cesarean section rates. This medical record-based study investigates the association patterns between too-low as well as too-high gestational weight gain, according to the 2009 Institute of Medicine (IOM) guidelines, and fetal growth, as well as birth mode and pregnancy outcome. The data of 11,755 singleton births that had taken place between 2010 and 2020 at the Public Clinic Donaustadt in Vienna, Austria, were analyzed. Birth weight, birth length, head circumference, APGAR scores, and pH values of the arterial umbilical cord blood described fetal growth as well as the vital parameters after birth. Gestational weight gain was classified as too low, recommended, or too high according to the different weight status categories of the IOM guidelines. Birth weight, birth length, and head circumference of the newborn were significantly increased (p < 0.001) among underweight, normal-weight, and overweight women who gained more weight than recommended. Among obese women, only birthweight was significantly (p < 0.001) higher among women who gained more weight than recommended. Furthermore, a too-high gestational weight gain was significantly associated with an increased risk of macrosomia and emergency cesarean sections among underweight, normal-weight, and overweight women, but not among obese ones. Obese and morbidly obese women experiencing excessive gestational weight gain showed no significantly increased risk of macrosomia or emergency cesarean section. However, among obese mothers, a too-low gestational weight gain reduced the risk of emergency cesarean sections significantly (p = 0.010). Consequently, the IOM recommendations for gestational weight gain fit only partly for pregnant women in Austria. In the case of obese and morbidly obese women, new guidelines for optimal pregnancy weight gain should be considered.

Suboptimal gestational weight gain and neonatal outcomes in low and middle income countries: individual participant data meta-analysis

OBJECTIVE

To estimate the associations between gestational weight gain (GWG) during pregnancy and neonatal outcomes in low and middle income countries.

DESIGN

Individual participant data meta-analysis.

SETTING

Prospective pregnancy studies from 24 low and middle income countries.

MAIN OUTCOME MEASURES

Nine neonatal outcomes related to timing (preterm birth) and anthropometry (weight, length, and head circumference) at birth, stillbirths, and neonatal death.

ANALYSIS METHODS

A systematic search was conducted in PubMed, Embase, and Web of Science which identified 53 prospective pregnancy studies published after the year 2000 with data on GWG, timing and anthropometry at birth, and neonatal mortality. GWG adequacy was defined as the ratio of the observed maternal weight gain over the recommended weight gain based on the Institute of Medicine body mass index specific guidelines, which are derived from data in high income settings, and the INTERGROWTH-21st GWG standards. Study specific estimates, adjusted for confounders, were generated and then pooled using random effects meta-analysis models. Maternal age and body mass index before pregnancy were examined as potential modifiers of the associations between GWG adequacy and neonatal outcomes.

RESULTS

Overall, 55% of participants had severely inadequate (<70%) or moderately inadequate (70% to <90%) GWG, 22% had adequate GWG (90-125%), and 23% had excessive GWG (≥125%). Severely inadequate GWG was associated with a higher risk of low birthweight (adjusted relative risk 1.62, 95% confidence interval 1.51 to 1.72; 48 studies, 93 337 participants; τ2=0.006), small for gestational age (1.44, 1.36 to 1.54; 51 studies, 93 191 participants; τ2=0.016), short for gestational age (1.47, 1.29 to 1.69; 40 studies, 83 827 participants; τ2=0.074), and microcephaly (1.57, 1.31 to 1.88; 31 studies, 80 046 participants; τ2=0.145) compared with adequate GWG. Excessive GWG was associated with a higher risk of preterm birth (1.22, 1.13 to 1.31; 48 studies, 103 762 participants; τ2=0.008), large for gestational age (1.44, 1.33 to 1.57; 47 studies, 90 044 participants; τ2=0.009), and macrosomia (1.52, 1.33 to 1.73; 29 studies, 68 138 participants; τ2=0) compared with adequate GWG. The direction and magnitude of the associations between GWG adequacy and several neonatal outcomes were modified by maternal age and body mass index before pregnancy.

CONCLUSIONS

Inadequate and excessive GWG are associated with a higher risk of adverse neonatal outcomes across settings. Interventions to promote optimal GWG during pregnancy are likely to reduce the burden of adverse neonatal outcomes, however further research is needed to assess optimal ranges of GWG based on data from low and middle income countries.

Vaginal microbiome in obesity and its impact on reproduction

A number of reproductive outcomes have been increasingly found to be affected by the vaginal microbiota. Obesity has become a global epidemic, affecting increasing numbers of reproductive-age women, and has been shown to be a risk factor for a number of adverse female health outcomes. A healthy vaginal microbiome is characterized by Lactobacillus-dominance, in particular Lactobacillus crispatus; obesity has been found to be associated with higher diversity and a lower likelihood of Lactobacillus-dominance. In this review, we summarize the evidence on the vaginal microbiome in obese women and the impact on reproductive outcomes such as conception rates, early pregnancy, and preterm birth. We further explore the mechanisms by which obesity may result in an altered microbial composition and highlight future avenues for therapeutic targeting of the vaginal microbiota.

The heterogeneous associations between gestational weight gain and adverse pregnancy outcomes in gestational diabetes mellitus according to abnormal glucose metabolism

OBJECTIVES

The gestational weight gain (GWG) and hyperglycemia are two key factors affecting adverse pregnancy outcomes among women with gestational diabetes mellitus (GDM). We aimed to investigate the combinatorial effect of abnormal glucose metabolism and GWG on adverse outcomes in GDM.

METHODS

This retrospective cohort study included 2611 pregnant women with GDM in Women's Hospital School of Medicine Zhejiang University. Bases on the OGTT glucose levels, we categorized the GDM cohort into three subgroups: impaired fasting glucose (IFG) group, impaired glucose tolerance (IGT) group, and combined impaired glucose (IFG&IGT) group.

RESULTS

Among pregnant women with IGT, insufficient GWG (IGWG) was an independent protective factor for pregnancy-induced hypertension syndrome (PIH) (aOR 0.55, 95% CI 0.32-0.95), macrosomia (0.38, 0.19-0.74) and large for gestational age (0.45, 0.32-0.62), as well as an independent risk factor for low birth weight infants (2.29, 1.24-4.22) and small for gestational age (1.94, 1.17-3.19); and excessive GWG (EGWG) was related to increased risks of PIH (1.68, 1.12-2.52), preterm delivery (1.82, 1.28-2.58), postpartum hemorrhage (1.85, 1.05-3.28), cesarean delivery (1.84, 1.38-2.46) and low body weight infants (2.36, 1.33-4.20). Moreover, EGWG was positively associated with PIH (3.27, 1.09-9.80) in the IFG group. But there were no significant associations between either IGWG or EGWG and any pregnancy outcomes in women with combined IFG&IGT.

CONCLUSIONS

The relationships between GWG and adverse outcomes were modified by abnormal glucose metabolism in women with GDM. Our results suggest that more specific GWG recommendations according to their metabolic state are needed for GDM.

Novel approaches to examining weight changes in pregnancies affected by obesity

BACKGROUND

Current gestational weight change (GWC) recommendations for obese individuals were established with limited evidence of the pattern and timing of weight change across pregnancy. Similarly, the recommendation of 5-9 kg does not differentiate by the severity of obesity.

OBJECTIVES

We sought to describe GWC trajectory classes by obesity grade and associated infant outcomes among a large, diverse cohort.

METHODS

The study population included 22,355 individuals with singleton pregnancies, obesity (BMI ≥30.0 kg/m2), and normal glucose tolerance who delivered at Kaiser Permanente Northern California between 2008 and 2013. Obesity grade-specific GWC trajectories were modeled at 38 wk using flexible latent class mixed modeling (package lcmm) in R. Multivariable Poisson or linear regression models estimated the associations between the GWC trajectory class and infant outcomes (size-for-gestational age and preterm birth) by obesity grade.

RESULTS

Five GWC trajectory classes were identified for each obesity grade, each with a distinct pattern of weight change before 15 wk (including loss, stability, and gain) followed by weight gain thereafter (low, moderate, and high). Two classes with high overall gain were associated with an increased risk for large for gestational age (LGA) in obesity grade 1 (IRR = 1.27; 95% CI: 1.10, 1.46; IRR = 1.47; 95% CI: 1.24, 1.74). Both high (IRR = 2.02; 95% CI: 1.61, 2.52; IRR = 1.98; 95% CI: 1.52, 2.58) and 2 moderate-gain classes (IRR = 1.40; 95% CI 1.14, 1.71; IRR = 1.51; 95% CI: 1.20, 1.90) were associated with LGA in grade 2, and only early loss/late moderate-gain class 3 (IRR = 1.30; 95% CI: 1.04, 1.62) was associated in grade 3. This class was also associated with preterm birth in grade 2. No associations were detected between GWC and small for gestational age (SGA).

CONCLUSIONS

Among the pregnancies affected by obesity, GWC was not linear or uniform. Different patterns of high gain were associated with an increased risk for LGA with the greatest magnitude in obesity grade 2, whereas GWC patterns were not associated with SGA.

A prospective registry analysis of psychosocial and metabolic health between women with and without metabolic syndrome after a complicated pregnancy

PURPOSE

Pregnancy complications affect over one quarter of Australian pregnancies, and this group of mothers is vulnerable and more likely to experience adverse cardiometabolic health outcomes in the postpartum period. Metabolic syndrome is common in this population and may be associated with postpartum mental health issues. However, this relationship remains poorly understood. To compare the differences in psychosocial parameters and mental health outcomes between women with metabolic syndrome and women without metabolic syndrome 6 months after a complicated pregnancy.

METHODS

This study is prospective registry analysis of women attending a postpartum healthy lifestyle clinic 6 months following a complicated pregnancy. Mental health measures included 9-item Patient Health Questionnaire (PHQ-9), 7-item Generalised Anxiety Disorder questionnaire (GAD-7), self-reported diagnosed history of depression, anxiety and/or other psychiatric condition, and current psychotropic medication use.

RESULTS

Women with metabolic syndrome reported significantly more subjective mental health concerns, were more likely to have a history of depression and other psychiatric diagnoses and were more likely prescribed psychotropic medications. However, there were no significant differences in PHQ-9 and GAD-7 scores.

CONCLUSION

Amongst new mothers who experienced complications of pregnancy, those with metabolic syndrome represent a particularly vulnerable group with regards to psychosocial disadvantage and mental health outcomes. These vulnerabilities may not be apparent when using common standardised cross-sectional mental health screening tools such as PHQ-9 and GAD-7.

Risk factors for preterm birth in pregnancies following bariatric surgery: an analysis of the Longitudinal Assessment of Bariatric Surgery-2

BACKGROUND

Bariatric surgery has been shown to increase the risk for preterm birth in a subsequent pregnancy. Determining factors that contribute to this heightened risk will inform the development of targeted interventions to improve birth outcomes postbariatric surgery.

OBJECTIVES

This study aimed to identify risk factors of preterm birth in pregnancies following bariatric surgery. Factors being considered were preoperative medical conditions and behaviors (e.g., obesity-associated co-morbidities, gastrointestinal symptoms, substance use), antenatal factors (e.g., prepregnancy body mass index, gestational weight gain), and surgery-specific factors (e.g., surgery type, surgery-to-conception interval).

SETTING

Bariatric surgery centers in the United States.

METHODS

This is a retrospective analysis of the Longitudinal Assessment of Bariatric Surgery-2. Participants were women who reported at least 1 singleton live birth during the 7-year postoperative period. Logistic regressions were used to identify risk factors of preterm birth, adjusting for covariates such as maternal age, race, and ethnicity.

RESULTS

Participants (n = 97) were mostly White (84.5%) and non-Hispanic (88.7%). At the time of surgery, the mean age was 29.4 ± 4.6 years, and the mean body mass index was 47.6 ± 6.3 kg/m2. The prevalence of preterm birth was 13.4%. Preoperative gastrointestinal symptoms significantly increased (odds ratio: 1.12; 95% confidence interval: 1.00-1.26), while unexpectedly, excessive versus adequate gestational weight gain (odds ratio: .12; 95% confidence interval: .02-1.00) decreased the odds of preterm birth following bariatric surgery.

CONCLUSIONS

This analysis identified potential risk and protective factors of preterm birth among pregnancies postbariatric surgery. However, given the small sample size, findings should be regarded as hypothesis-generating and merit further study.

Weight gain during pregnancy: A narrative review on the recent evidences

Gestational weight gain is necessary for the normal fetus development, in fact a series of studies have evidenced that both low and excessive gestational weight gain is associated with negative fetal-neonatal outcomes. So, evidences on the optimal gestational weight gain across the ranges of the pre-pregnancy maternal body mass index are necessary. In this context, while for normal weight and underweight the recommendations of IOM are clearly stated and supported by well designed and conducted clinical studies, those for the obese pregnant women are even today debated. Pre-pregnancy obesity is associated with high risk to develop hypertension, gestational diabetes, cesarean section and high birth weight. The Institute of Medicine guidelines, in 2009, recommended that women with obesity gain 11-20 lb at a rate of 0.5 lb/week during the second and third trimesters of pregnancy. Successively, taking into account a series of meta-analysis, the American College of Obstetricians and Gynecologists emphasized that the IOM weight gain targets for obese pregnant women are too high. However the high risk to have babies small for gestational age, related to a low weight gain or a losing of weight during pregnancy, has also been demonstrated. More recent studies have taken into consideration the maternal and fetal outcomes of obese pregnant women with different obesity class (I,II,III) and different weight gain during pregnancy. The analysis of these studies, discussed in this narrative review, show that the appropriate gestational weight gain should be personalized considering the three obesity class; furthermore both an upper and lower limit of gestational weight gain should be reconsidered in order to prevent the negative maternal and fetal outcomes in these women.

Association Between Household and Maternal Socioeconomic Factors with Birth Outcomes in the Democratic Republic of Congo and South Africa: A Comparative Study

OBJECTIVE

To assess and compare the associations between household socioeconomic (SES) factors with birth outcomes (low birth weight (LBW), small-for-gestational age (SGA) and preterm birth (PTB)) in the Democratic Republic of Congo (DRC) and South Africa (SA).

METHODS

Cross-sectional data of mother-newborn pairs collected in 2017 in the DRC were compared with mother-newborn pairs data from the SA Soweto first 1000-days pregnancy cohort study (2013-2016). Country-specific and pooled multivariable logistic regressions analyses assessed the associations between maternal education, marital status, and housing with LBW, SGA, and PTB adjusted for maternal anthropometry and obstetric factors.

RESULTS

1084 mother-newborn pairs were recruited (DRC: 256; SA: 828). The rates of LBW, PTB and SGA were, 11.5%, 17.1% and 32.8% in the DRC and 15.9%, 10.5% and 20.1% in SA. SES factors differed between countries and sex. In the DRC, being married decreased the odds of having LBW and PTB children by 86% and 80%, respectively. In SA, being a mother with secondary level of education and above was associated with 86% reduced odds of SGA. In the pooled analyses, women with secondary level of education and above had a 2.2-fold increase in odds of giving birth to a PTB newborn. Country of residence and maternal nutritional status were stronger predictors of birth outcomes than SES factors.

CONCLUSION FOR PRACTICE

In sub-Saharan Africa, policies aiming to alleviate women's education combined with improved social support and household SES prior to and during pregnancy are critical to optimal neonatal outcomes and strategic to achieve the Sustainable Development Goals.

Sample Preparation Methods for Lipidomics Approaches Used in Studies of Obesity

Obesity is associated with alterations in the composition and amounts of lipids. Lipids have over 1.7 million representatives. Most lipid groups differ in composition, properties and chemical structure. These small molecules control various metabolic pathways, determine the metabolism of other compounds and are substrates for the syntheses of different derivatives. Recently, lipidomics has become an important branch of medical/clinical sciences similar to proteomics and genomics. Due to the much higher lipid accumulation in obese patients and many alterations in the compositions of various groups of lipids, the methods used for sample preparations for lipidomic studies of samples from obese subjects sometimes have to be modified. Appropriate sample preparation methods allow for the identification of a wide range of analytes by advanced analytical methods, including mass spectrometry. This is especially the case in studies with obese subjects, as the amounts of some lipids are much higher, others are present in trace amounts, and obese subjects have some specific alterations of the lipid profile. As a result, it is best to use a method previously tested on samples from obese subjects. However, most of these methods can be also used in healthy, nonobese subjects or patients with other dyslipidemias. This review is an overview of sample preparation methods for analysis as one of the major critical steps in the overall analytical procedure.

Shotgun sequencing of the vaginal microbiome reveals both a species and functional potential signature of preterm birth

An association between the vaginal microbiota and preterm birth (PTB) has been reported in several research studies. Population shifts from high proportions of lactobacilli to mixed species communities, as seen with bacterial vaginosis, have been linked to a twofold increased risk of PTB. Despite the increasing number of studies using next-generation sequencing technologies, primarily involving 16S rRNA-based approaches, to investigate the vaginal microbiota during pregnancy, no distinct microbial signature has been associated with PTB. Shotgun metagenomic sequencing offers a powerful tool to reveal community structures and their gene functions at a far greater resolution than amplicon sequencing. In this study, we employ shotgun metagenomic sequencing to compare the vaginal microbiota of women at high risk of preterm birth (n = 35) vs. a low-risk control group (n = 14). Although microbial diversity and richness did not differ between groups, there were significant differences in terms of individual species. In particular, Lactobacillus crispatus was associated with samples from a full-term pregnancy, whereas one community state-type was associated with samples from preterm pregnancies. Furthermore, by predicting gene functions, the functional potential of the preterm microbiota was different from that of full-term equivalent. Taken together, we observed a discrete structural and functional difference in the microbial composition of the vagina in women who deliver preterm. Importance: with an estimated 15 million cases annually, spontaneous preterm birth (PTB) is the leading cause of death in infants under the age of five years. The ability to accurately identify pregnancies at risk of spontaneous PTB is therefore of utmost importance. However, no single cause is attributable. Microbial infection is a known risk factor, yet the role of vaginal microbes is poorly understood. Using high-resolution DNA-sequencing techniques, we investigate the microbial communities present in the vaginal tracts of women deemed high risk for PTB. We confirm that Lactobacillus crispatus is strongly linked to full-term pregnancies, whereas other microbial communities associate with PTB. Importantly, we show that the specific functions of the microbes present in PTB samples differs from FTB samples, highlighting the power of our sequencing approach. This information enables us to begin understanding the specific microbial traits that may be influencing PTB, beyond the presence or absence of microbial taxa.

Associations between gestational weight gain and preterm birth in Puerto Rico

BACKGROUND

Preterm birth (PTB; gestational age < 37 weeks) is the leading cause of infant morbidity and mortality worldwide. Low and excessive gestational weight gain (GWG) have been previously cited as risk factors for PTB, however the magnitude of association varies across populations. No studies have examined low and excessive GWG as modifiable risk factors for PTB in Puerto Rico, an area with inexplicably high PTB rates.

METHODS

To examine the relationship between GWG and PTB, we conducted a retrospective analysis using birth certificate data files from the Puerto Rico Department of Health from 2005 to 2012. GWG was standardized to a 40-week gestational duration and was categorized into low, adequate, or excessive for each category of pre-pregnancy body mass index using American College of Obstetricians and Gynecologists guidelines. Logistic regression was used to determine the crude and adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between GWG and PTB.

RESULTS

There were 320,695 births included in this analysis; 40.6% with high GWG and 27.3% with low GWG. A greater percentage of women with low GWG were less than 20 years of age, had less than a high school education, and were underweight compared to women with adequate and excessive GWG. Women with low compared to adequate GWG had increased odds of PTB (OR = 1.34, 95% CI = 1.30-1.37). However, excessive compared to adequate GWG was not associated with PTB (OR = 0.99, 95% CI = 0.97-1.02).

CONCLUSIONS

Among women in Puerto Rico, low GWG was associated with increased odds of PTB. With the exception of obesity, these associations persisted within all strata of pre-pregnancy body mass index, highlighting the importance of maintaining a healthy weight during pregnancy. Future research should examine other factors that may contribute to GWG, such as dietary nutrients, and explore pathways through which GWG may be contributing to PTB.

Early life risk and resiliency factors and their influences on developmental outcomes and disease pathways: a rapid evidence review of systematic reviews and meta-analyses

The Developmental Origins of Health and Disease (DOHaD) framework aims to understand how environmental exposures in early life shape lifecycle health. Our understanding and the ability to prevent poor health outcomes and enrich for resiliency remain limited, in part, because exposure-outcome relationships are complex and poorly defined. We, therefore, aimed to determine the major DOHaD risk and resilience factors. A systematic approach with a 3-level screening process was used to conduct our Rapid Evidence Review following the established guidelines. Scientific databases using DOHaD-related keywords were searched to capture articles between January 1, 2009 and April 19, 2019. A final total of 56 systematic reviews/meta-analyses were obtained. Studies were categorized into domains based on primary exposures and outcomes investigated. Primary summary statistics and extracted data from the studies are presented in Graphical Overview for Evidence Reviews diagrams. There was substantial heterogeneity within and between studies. While global trends showed an increase in DOHaD publications over the last decade, the majority of data reported were from high-income countries. Articles were categorized under six exposure domains: Early Life Nutrition, Maternal/Paternal Health, Maternal/Paternal Psychological Exposure, Toxicants/Environment, Social Determinants, and Others. Studies examining social determinants of health and paternal influences were underrepresented. Only 23% of the articles explored resiliency factors. We synthesized major evidence on relationships between early life exposures and developmental and health outcomes, identifying risk and resiliency factors that influence later life health. Our findings provide insight into important trends and gaps in knowledge within many exposures and outcome domains.

The impact of excessive gestational weight gain timing on neonatal outcomes in women with class III obesity

OBJECTIVE

This study evaluated the influence of early gestational weight gain (GWG) on neonatal outcomes among women with class III obesity.

STUDY DESIGN

Retrospective cohort of women with class III obesity who gained more than the Institute of Medicine (IOM) guidelines (>20lbs). Women gaining ≥75% of total gestational weight prior to 28 weeks (EWG) were compared to women gaining <75% of their total weight prior to 28 weeks (SWG). The primary outcome was a neonatal composite morbidity and mortality. Secondary outcomes included individual components of composite and LGA.

RESULTS

Of 144 women identified, 42 (29.2%) had EWG and 102 (70.8%) had SWG. Though 11% of the total population had composite neonatal morbidity, this did not differ between groups (p = .4). LGA was nearly twice as common in the SWG group (41% vs 26%, p = .13). EWG was associated with decreased risk of LGA (AOR 0.25 95% CI 0.08, 0.78) and lower median birth weight (AOR -312 g 95% CI -534.7, -90.2).

CONCLUSION

Though adverse neonatal outcomes were common in this population, timing of gestational weight gain was not correlated. Increased rates of LGA and higher median birth weight in the SWG group suggests excessive GWG continuing in the third trimester of pregnancy may be of import for neonatal size.

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.

Role of Body Mass Index and gestational weight gain on preterm birth and adverse perinatal outcomes

The association of body mass index (BMI) and gestational weight gain (GWG) with preterm birth (PTB) remains controversial in the literature. To evaluate different maternal BMI and GWG categories, according to the initial BMI, in relation to different PTB subtypes and perinatal outcomes, we conducted a secondary analysis of a multicentre cross-sectional study, along with a nested case-control study including PTB from 20 centers in Brazil. Pre-pregnancy underweight was associated with a lower risk of provider-initiated PTB, while overweight and obesity were associated with a higher risk of provider-initiated PTB and a lower risk of spontaneous preterm birth. Insufficient gestational weight gain was associated with a higher prevalence of spontaneous PTB and preterm premature rupture of membranes. Excessive GWG correlated with a higher prevalence of provider-initiated PTB or preterm premature rupture of membranes. Irrespective of the initial BMI, the greater the rate of GWG, the higher the predicted probability of all PTB subtypes, except for spontaneous PTB in underweight women and those with normal BMI. On multivariate analysis, the initial BMI was shown to be the only factor associated with pi-PTB. Briefly, further studies evaluating the risk for PTB should consider that GWG may have a different role depending on the initial BMI and PTB subtype.

Gestational weight gain outside the Institute of Medicine recommendations and adverse pregnancy outcomes: analysis using individual participant data from randomised trials

BACKGROUND

High Body Mass Index (BMI) and gestational weight gain (GWG) affect an increasing number of pregnancies. The Institute of Medicine (IOM) has issued recommendations on the optimal GWG for women according to their pre-pregnancy BMI (healthy, overweight or obese). It has been shown that pregnant women rarely met the recommendations; however, it is unclear by how much. Previous studies also adjusted the analyses for various women's characteristics making their comparison challenging.

METHODS

We analysed individual participant data (IPD) of healthy women with a singleton pregnancy and a BMI of 18.5 kg/m2 or more from the control arms of 36 randomised trials (16 countries). Adjusted odds ratios (aOR) and 95% confidence intervals (CI) were used to describe the association between GWG outside (above or below) the IOM recommendations (2009) and risks of caesarean section, preterm birth, and large or small for gestational age (LGA or SGA) infants. The association was examined overall, within the BMI categories and by quartile of GWG departure from the IOM recommendations. We obtained aOR using mixed-effects logistic regression, accounting for the within-study clustering and a priori identified characteristics.

RESULTS

Out of 4429 women (from 33 trials) meeting the inclusion criteria, two thirds gained weight outside the IOM recommendations (1646 above; 1291 below). The median GWG outside the IOM recommendations was 3.1 kg above and 2.7 kg below. In comparison to GWG within the IOM recommendations, GWG above was associated with increased odds of caesarean section (aOR 1.50; 95%CI 1.25, 1.80), LGA (2.00; 1.58, 2.54), and reduced odds of SGA (0.66; 0.50, 0.87); no significant effect on preterm birth was detected. The relationship between GWG below the IOM recommendation and caesarean section or LGA was inconclusive; however, the odds of preterm birth (1.94; 1.31, 2.28) and SGA (1.52; 1.18, 1.96) were increased.

CONCLUSIONS

Consistently with previous findings, adherence to the IOM recommendations seem to help achieve better pregnancy outcomes. Nevertheless, even in the context of clinical trials, women find it difficult to adhere to them. Further research should focus on identifying ways of achieving a healthier GWG as defined by the IOM recommendations.

Impact of prenatal exercise on neonatal and childhood outcomes: a systematic review and meta-analysis

Objective

We aimed to identify the relationship between maternal prenatal exercise and birth complications, and neonatal and childhood morphometric, metabolic and developmental outcomes.

Design

Systematic review with random-effects meta-analysis and meta-regression.

Data sources

Online databases were searched up to 6 January 2017.

Study eligibility criteria

Studies of all designs were eligible (except case studies and reviews) if published in English, Spanish or French, and contained information on the relevant population (pregnant women without contraindication to exercise), intervention (subjective/objective measures of frequency, intensity, duration, volume or type of exercise, alone (‘exercise-only’) or in combination with other intervention components (eg, dietary; ‘exercise+cointervention’)), comparator (no exercise or different frequency, intensity, duration, volume, type or trimester of exercise) and outcomes (preterm birth, gestational age at delivery, birth weight, low birth weight (<2500 g), high birth weight (>4000 g), small for gestational age, large for gestational age, intrauterine growth restriction, neonatal hypoglycaemia, metabolic acidosis (cord blood pH, base excess), hyperbilirubinaemia, Apgar scores, neonatal intensive care unit admittance, shoulder dystocia, brachial plexus injury, neonatal body composition (per cent body fat, body weight, body mass index (BMI), ponderal index), childhood obesity (per cent body fat, body weight, BMI) and developmental milestones (including cognitive, psychosocial, motor skills)).

Results

A total of 135 studies (n=166 094) were included. There was ‘high’ quality evidence from exercise-only randomised controlled trials (RCTs) showing a 39% reduction in the odds of having a baby >4000 g (macrosomia: 15 RCTs, n=3670; OR 0.61, 95% CI 0.41 to 0.92) in women who exercised compared with women who did not exercise, without affecting the odds of growth-restricted, preterm or low birth weight babies. Prenatal exercise was not associated with the other neonatal or infant outcomes that were examined.

Conclusions

Prenatal exercise is safe and beneficial for the fetus. Maternal exercise was associated with reduced odds of macrosomia (abnormally large babies) and was not associated with neonatal complications or adverse childhood outcomes.

Review shows that maternal obesity induces serious adverse neonatal effects and is associated with childhood obesity in their offspring

AIM

Obesity at the start of pregnancy has been rising worldwide, increasing the risk of maternal complications. We reviewed the independent effects of maternal obesity during pregnancy on neonatal adverse outcomes and the risk of childhood obesity and adverse cardio-metabolic profiles.

METHODS

We searched MEDLINE for papers published in English between December 2007 and November 2017, focusing primarily on human studies published in the last five years. However, we also chose to highlight examples derived from model animals that could bring mechanistic insight and preventive and therapeutic avenues.

RESULTS

Our review showed that maternal obesity had independent effects on neonatal adverse outcomes such as macrosomia, perinatal mortality and birth defects. Maternal obesity alone increased the risks for adverse neonatal outcomes, including macrosomia, perinatal mortality, induced preterm birth and birth defects. In association with excess gestational weight gain, mainly early in pregnancy, increased the risks of childhood obesity, higher fat mass and, to a smaller extent, adverse cardio-metabolic profiles. Animal models highlighted sexually dimorphic responses to maternal obesity.

CONCLUSION

Maternal obesity induced serious adverse neonatal effects and was associated with childhood obesity in their offspring. The peri-conceptional period is critical for metabolic programming, and obese women need close monitoring from conception.

Prevention of Excessive Gestational Weight Gain and Postpartum Weight Retention

PURPOSE OF REVIEW

The purpose of this review is to summarize the current evidence on the prevention of excessive gestational weight gain (GWG) and reduction of postpartum weight retention (PPWR) by lifestyle intervention and pharmacotherapy.

RECENT FINDINGS

Recent findings demonstrate that tailored nutrition counseling and adapting certain eating patterns, supervised exercise programs aiming at achieving at least moderate level of physical activity, and interactive and monitored behavior change interventions are effective in reducing excessive GWG and PPWR. Among the pharmacologic agents, Metformin has been shown to reduce GWG. Excessive GWG and PPWR are associated with adverse maternal and neonatal outcomes. Recent evidence shows that weight during gestation and the postpartum period can be significantly reduced by more frequent nutrition counseling sessions on balanced diet focusing on healthier food choices and eating patterns, supervised moderate-intensity exercise for at least 30 min three times a week, and interactive behavior change interventions with regular feedback and follow-up. The benefits on weight are seen when these interventions are utilized together in a multimodality approach. Metformin is effective in preventing excessive GWG but has no impact on neonatal outcomes.

Avoiding excessive pregnancy weight gain to obtain better pregnancy outcomes in Taiwan

Pregnancy weight gain may be associated with adverse pregnancy outcomes. The article aims to explore the relationship between weight change and pregnancy outcome in the Taiwanese pregnant women.The retrospective cohort study enrolled women with vertex singleton pregnancy at University-associated Hospital between 2011 and 2014. Pregnancy weight change was separated into 3 groups, based on the Institute of Medicine (IOM) guidelines: below (n = 221); within (n = 544); and above (n = 382). Analysis of variance, χ tests, generalized linear models, and logistic regression models were used for statistical comparisons.Pregnant women with weight change above IOM guidelines had a significant increase in both maternal and perinatal complications compared with normal controls (odds ratio [OR] 1.65, 95% confidence interval [CI] 1.03-1.98; P = .043; OR 1.45, 95% CI 1.01-1.87; P = .049, respectively). This finding was not found in pregnant women with weight gain below IOM guidelines. Moreover, age (OR 1.08, 95% CI 1.02-1.15; P = .0011), pre-pregnancy weight (OR 1.04, 95% CI 1.01-1.09; P = .0008), pre-pregnancy body mass index (BMI; OR 1.15, 95% CI 1.06-1.30; P < .0001), weight at the time of delivery (OR 1.05, 95% CI 1.02-1.13; P < .0001) and BMI at the time of delivery (OR 1.15, 95% CI 1.06-1.39; P < .0001), all contributed to increased maternal complications but not perinatal complications, whereas parity (OR 0.23, 95% CI 0.12-0.41; P < .0001) and gestational age (OR 0.50, 95% CI 0.35-0.62; P < .001) were associated with fewer maternal complications.Our study reconfirmed that for Taiwanese pregnant women, the approximate pregnancy weight gain recommended by IOM in 2009 was associated with the fewest maternal and perinatal complications. If approximate pregnancy weight gain cannot be attained, even less weight gain during pregnancy is still reasonable without significantly and adversely affecting maternal and perinatal outcomes in Taiwan.

Obstetric and perinatal outcomes in subfertile patients who conceived following low technology interventions for fertility enhancement: a comprehensive review

PURPOSE

Low technology interventions for fertility enhancement (LTIFE) are strategies that avoid retrieval, handling, and manipulation of female gametes. The definition of LTIFE is yet to be widely accepted and clarified, but they are commonly used in milder cases of infertility and subfertility. Based on these considerations, the aim of the present study was comprehensively to review and investigate the obstetric and perinatal outcomes in subfertile patients who underwent LTIFE.

METHODS

A literature search up to May 2017 was performed in IBSS, SocINDEX, Institute for Scientific Information, PubMed, Web of Science, and Google Scholar. An evidence-based hierarchy was used according to The Oxford Centre for Evidence-Based Medicine to determine which articles to include and analyze, and to provide a level of evidence of each association between intervention and outcome.

RESULTS

This analysis identified preliminary and low-grade evidence on the influence of LTIFE on obstetric and perinatal outcomes in subfertile women.

CONCLUSIONS

LTIFE women should deserve major consideration from Clinicians/Researchers of Reproductive Medicine, because these treatments could be potentially responsible for mothers' and babies' complications. So far, the lack of well-designed and unbiased studies makes further conclusions difficult to be drawn.

Association of Gestational Weight Gain With Maternal and Infant Outcomes: A Systematic Review and Meta-analysis

IMPORTANCE

Body mass index (BMI) and gestational weight gain are increasing globally. In 2009, the Institute of Medicine (IOM) provided specific recommendations regarding the ideal gestational weight gain. However, the association between gestational weight gain consistent with theIOM guidelines and pregnancy outcomes is unclear.

OBJECTIVE

To perform a systematic review, meta-analysis, and metaregression to evaluate associations between gestational weight gain above or below the IOM guidelines (gain of 12.5-18 kg for underweight women [BMI <18.5]; 11.5-16 kg for normal-weight women [BMI 18.5-24.9]; 7-11 kg for overweight women [BMI 25-29.9]; and 5-9 kg for obese women [BMI ≥30]) and maternal and infant outcomes.

DATA SOURCES AND STUDY SELECTION

Search of EMBASE, Evidence-Based Medicine Reviews, MEDLINE, and MEDLINE In-Process between January 1, 1999, and February 7, 2017, for observational studies stratified by prepregnancy BMI category and total gestational weight gain.

DATA EXTRACTION AND SYNTHESIS

Data were extracted by 2 independent reviewers. Odds ratios (ORs) and absolute risk differences (ARDs) per live birth were calculated using a random-effects model based on a subset of studies with available data.

MAIN OUTCOMES AND MEASURES

Primary outcomes were small for gestational age (SGA), preterm birth, and large for gestational age (LGA). Secondary outcomes were macrosomia, cesarean delivery, and gestational diabetes mellitus.

RESULTS

Of 5354 identified studies, 23 (n = 1 309 136 women) met inclusion criteria. Gestational weight gain was below or above guidelines in 23% and 47% of pregnancies, respectively. Gestational weight gain below the recommendations was associated with higher risk of SGA (OR, 1.53 [95% CI, 1.44-1.64]; ARD, 5% [95% CI, 4%-6%]) and preterm birth (OR, 1.70 [1.32-2.20]; ARD, 5% [3%-8%]) and lower risk of LGA (OR, 0.59 [0.55-0.64]; ARD, -2% [-10% to -6%]) and macrosomia (OR, 0.60 [0.52-0.68]; ARD, -2% [-3% to -1%]); cesarean delivery showed no significant difference (OR, 0.98 [0.96-1.02]; ARD, 0% [-2% to 1%]). Gestational weight gain above the recommendations was associated with lower risk of SGA (OR, 0.66 [0.63-0.69]; ARD, -3%; [-4% to -2%]) and preterm birth (OR, 0.77 [0.69-0.86]; ARD, -2% [-2% to -1%]) and higher risk of LGA (OR, 1.85 [1.76-1.95]; ARD, 4% [2%-5%]), macrosomia (OR, 1.95 [1.79-2.11]; ARD, 6% [4%-9%]), and cesarean delivery (OR, 1.30 [1.25-1.35]; ARD, 4% [3%-6%]). Gestational diabetes mellitus could not be evaluated because of the nature of available data.

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis of more than 1 million pregnant women, 47% had gestational weight gain greater than IOM recommendations and 23% had gestational weight gain less than IOM recommendations. Gestational weight gain greater than or less than guideline recommendations, compared with weight gain within recommended levels, was associated with higher risk of adverse maternal and infant outcomes.

Physical Exercise During Pregnancy - How Active Are Pregnant Women in Germany and How Well Informed?

INTRODUCTION

There is sufficient evidence showing the positive effects of physical exercise on various aspects of pregnancy. This study evaluates knowledge and status of physical exercise among pregnant women.

METHODS

The standardised paper-pencil questionnaire "Pregnancy Physical Activity Questionnaire" (PPAQ) as well as general demographic questions were used to assess the exercise behaviour of study participants. 83 questionnaires completed by women presenting to the Kiel University Hospital for antenatal assessment were included in the analysis.

RESULTS

At the time of questionnaire completion 10 women were in the first trimester of pregnancy, 64 in the second, and 9 in the third. Just less than 90% of participants felt they had been informed "sufficiently" on the topic physical exercise during pregnancy, over 50% felt they were "well" or "very well" informed. Just less than half of participants received their information from a doctor (either their gynaecologist or general practitioner) and none of these felt "insufficiently" informed. Almost 80% of participants reported still doing no sport or less exercise than before falling pregnant. The maximum proportional energy expenditure for recreational activity - just under 20% - was in the third trimester. Women who felt they had been well counselled tended to have higher activity levels.

CONCLUSION

Study participants demonstrated a clear decline in physical exercise during pregnancy despite clear evidence of the benefits of regular exercise for pregnant women, and despite participants feeling they were well informed. Detailed information on the recommendations for physical exertion in pregnancy should form an integral part of antenatal counselling.

Perspectives in obesity and pregnancy

Obesity is currently recognized as a health epidemic worldwide. Its prevalence has doubled in the last three decades. Obesity is a complex clinical picture associated with physical, physiologic, hormonal, genetic, cultural, socioeconomic and environmental factors. The rate of obesity is also increasing in the pregnant women population. Maternal obesity is associated with less than optimal obstetrical, fetal and neonatal outcomes. It is also associated with significant adverse long-term effects on both obese parturients and the infants born from obese women. A number of guidelines have been published to educate health care workers and the general population in an attempt to develop effective interventions on a large scale to prevent obesity. These guidelines are multiple, confusing and inconsistent. There are no standard recommendations regarding gestational weight gaining goals, nutrients and additional elements necessary for certain obese women who have been treated with bariatric surgical procedures, screening for metabolic diseases such as diabetes, additional preventive health care services indicated for obese women in the pregnancy planning stages, during prenatal care, in the immediate post-partum period and as a long-term approach for health preservation. In 2013, the American Medical Association supported by several US national medical specialty organizations published Resolution 420 (A-13) recognizing obesity as a disease state with multiple pathophysiological aspects requiring a range of interventions to improve its prevention and treatment. The goal of this decision was to encourage a broader spectrum of health care benefits insurance coverage for the prevention and treatment of obesity. There are a number of myths and misconceptions associated with obesity. These perspectives present our views and clinical experience with a partial review of recent bibliography addressing the associations between obese reproductive age women and their risks during pregnancy.

Pregnancy complications in spontaneous and assisted conceptions of women with infertility and subfertility factors. A comprehensive review

In the literature, there is growing evidence that assisted reproductive techniques increase the risk of pregnancy complications in subfertile couples. Moreover, many concomitant preconception risk factors for subfertility are frequently present in the same subject and increase the risk of pregnancy complications. This review aimed to summarize in a systematic fashion the best current evidence regarding the effects of preconception maternal factors on maternal and neonatal outcomes. A literature search up to March 2016 was performed in IBSS, SocINDEX, Institute for Scientific Information, PubMed, Web of Science and Google Scholar. An evidence-based hierarchy was used to determine which articles to include and analyse. Available data show that the risk of pregnancy complications in spontaneous and assisted conceptions is likely multifactorial, and the magnitude of this risk is probably very different according specific subgroups of patients. Notwithstanding the only moderate level and quality of the available evidence, available data suggest that the presence and the treatment of specific preconception cofactors of subfertility should be always taken into account both in clinical practice and for scientific purposes.