Maternal Body Mass Index Category Research Articles

Maternal early pregnancy body mass index and risk of sleep apnea in the offspring.

To investigate the association between maternal early pregnancy body mass index (BMI) and offspring sleep apnea diagnosis. We conducted a nationwide cohort study among 3,281,803 singleton live births in Sweden born 1983-2015. Using national registers with prospectively recorded information, we followed participants for a sleep apnea diagnosis from 2 to up to 35 years of age. We compared sleep apnea risks by early pregnancy BMI categories using hazard ratios (HR) with 95% confidence intervals (CI) from adjusted Cox models. To address confounding by factors shared within families, we conducted sibling-controlled analyses and studied the relation of siblings' maternal BMI with index offspring's sleep apnea risk. There were 17,830 sleep apnea diagnoses. Maternal early pregnancy BMI was positively associated with offspring sleep apnea risk; compared with women with normal BMI (18.5-24.9), adjusted HR (95% CI) of offspring sleep apnea for maternal BMI categories 25.0-29.9 (overweight), 30.0-34.9 (obesity class I), and ≥35.0 (obesity class II or III) were, respectively, 1.14 (1.09, 1.19), 1.28 (1.20, 1.36), and 1.40 (1.27, 1.54). Corresponding HR from sibling-controlled analyses representing risk change for maternal BMI differences between pregnancies were, respectively, 1.13 (1.01, 1.26), 1.17 (0.97, 1.42), and 1.32 (0.97, 1.80). HR by siblings' maternal BMI were attenuated, suggesting a weak role for shared familial factors. Other pregnancy, birth, and neonatal complications were associated with offspring sleep apnea risk, but did not substantially mediate the association with maternal obesity. Maternal overweight and obesity are associated with offspring sleep apnea risk in a dose-response manner.

The impact of prepregnancy body mass index on pregnancy and neonatal outcomes.

The obesity epidemic in the United States is continuing to worsen. Obesity is a known risk factor for pregnancy morbidity. However, many studies use the patient's body mass index (BMI) at the time of delivery, do not stratify by class of obesity, or utilize billing codes as the basis of their study, which are noted to be inaccurate. This study aims to investigate the prepregnancy BMI class specific risks for pregnancy and neonatal complications based on a prepregnancy BMI class. We conducted a retrospective cohort study of40,256 pregnant women with 55,202 singleton births between October 16, 2007 and December 3, 2023. We assessed the risk of pregnancy and neonatal morbidity based on the maternal prepregnancy BMI category. The primary outcome was composite maternal morbidity, including hypertensive disorders of pregnancy (i.e.,gestational hypertension [GHTN] and preeclampsia), and gestational diabetes mellitus (GDM), adjusted for pregestational diabetes mellitus and chronic hypertension (cHTN). Secondary maternal outcomes included preterm premature rupture of membranes (PPROM), preterm delivery (PTD<37 and <32weeks), induction of labor (IOL), cesarean delivery (CD), and postpartum hemorrhage (PPH). Neonatal outcomes included a composite adverse outcome (including stillbirth, intraventricular hemorrhage (IVH), hypoglycemia, respiratory distress syndrome [RDS], APGAR [Appearance, Pulse, Grimace, Activity, and Respiration] <7 at 5 min, and neonatal intensive care unit [NICU] admission), birthweight, fetal growth restriction (FGR), and macrosomia. Composite maternal morbidity (odds ratio [OR] 4.40,confidence interval [CI] 3.70-5.22 for class III obesity [BMI≥40.0 kg/m2] compared with normal BMI), hypertensive disorders of pregnancy (HDP), GDM, PTD, IOL, CD, PPH, neonatal composite morbidity, hypoglycemia, RDS, APGAR<7 at 5 min, NICU admission, and macrosomia showed a significant increasing test of trend among BMI classes. Increased BMI was protective for FGR. Our data provides BMI-class specific odds ratios (ORs) for adverse pregnancy outcomes. Increased BMI class significantly increases the risk of HDP, GDM, IOL, CD, composite adverse neonatal outcomes, and macrosomia, and decreases the risk of FGR. Attaining a healthier BMI category prior to conception may lower pregnancy morbidity.

Insights into non-informative results from non-invasive prenatal screening through gestational age, maternal BMI, and age analyses.

The discovery of cell-free fetal DNA fragments in the maternal plasma initiated a novel testing method in prenatal care, called non-invasive prenatal screening (NIPS). One of the limitations of NIPS is the necessity for a sufficient proportion of fetal fragments in the analyzed circulating DNA mixture (fetal fraction), otherwise, the sample is uninterpretable. We present the effect of gestational age, maternal body mass index (BMI), and maternal age on the fetal fraction (FF) of the sample. We retrospectively analyzed data from 5543 pregnant women with a single male fetus who underwent NIPS from which 189 samples received a repeat testing due to an insufficient FF. We showed the relationship between the failure rate of the samples after the repeated analysis, the FF, and the gestational age at the first sampling. Next, we found that different maternal BMI categories affect the FF and thus the chance of an informative redraw. A better understanding of the factors affecting the FF will reduce the number of non-informative calls from repeated analyzes. In this study, we provide helpful information to clinicians on how to approach non-informative analyses.

Grandmaternal body mass index in early pregnancy and risk of grandoffspring stillbirth: a nationwide, 3-generation cohort study.

We investigated the association between maternal grandmaternal early pregnancy body mass index (BMI) and grandoffspring stillbirth risk in a Swedish population-based 3-generation cohort of 176 908 grandmothers (F0), 197 579 mothers (F1), and 316 459 grandoffspring (F2) born 1997-2016. There were 998 stillbirths (risk, 3.2 per 1000 births). Compared with grandmaternal BMI 18.5-24.9, adjusted relative risks (RRs) of grandoffspring stillbirth for BMIs of 25.0-29.9 and ≥30.0 were, respectively, 1.41 (95% CI, 1.15-1.72) and 1.62 (95% CI, 1.14-2.30). RRs for corresponding maternal (F1) BMI categories were, respectively, 1.32 (95% CI, 1.06-1.65) and 1.77 (95% CI, 1.39-2.25). Maternal BMI mediated only 19% of this relationship. Grandmaternal preeclampsia and maternal small-for-gestational age (SGA) birth were related to increased F2 stillbirth risk but did not mediate the association between grandmaternal BMI and grandoffspring stillbirth risk. To explore whether this association was explained by factors shared within families, we studied the relationship of maternal full sisters' BMI and stillbirth risk in 101 368 pregnancies. Stillbirth RRs for full sisters' BMI 25.0-29.9 and ≥30.0 compared with 18.5-24.9 were, respectively, 0.76 (95% CI, 0.51-1.13) and 0.88 (95% CI, 0.55-1.40). In conclusion, grandmaternal overweight and obesity were associated with grandoffspring stillbirth. This association is not fully explained by shared familial factors.

Association of overweight and obesity with cumulative live birth rates according to women's age: A cohort study of 26 567 treatment cycles.

To evaluate the effect of age on the association between maternal body mass index (BMI) and cumulative live birth rates (CLBRs) following in vitro fertilization treatment. We retrospectively analyzed the data of 26 567 women undergoing in vitro fertilization/intracytoplasmic sperm injection from 2016 to 2019. We conducted multivariate regression analysis of the association between CLBRs and maternal BMI and age category. A total of 16 626 (62.58%) patients achieved a live birth. Women with obesity had significantly decreased CLBRs compared with women who had normal weight (odds ratio [OR] 0.73 [95% confidence interval (CI), 0.66-0.80]). The significant interaction between age and BMI suggested that the impact of BMI on CLBRs was moderated by women's age (P interaction <0.001). The association between obesity and CLBRs was inverse among women aged <30 years (OR, 0.63 [95% CI, 0.54-0.73]), 30 to 34 years (OR, 0.79 [95% CI, 0.67-0.93]), and 35 to 37 years (OR, 0.71 [95% CI, 0.52-0.98]); however, decreases in CLBRs with obesity were not observed in women aged 38 to 40 years (OR, 1.17 [95% CI, 0.70-1.94]) and ≥ 41 years (OR, 1.25 [95% CI, 0.53-2.96]). Maternal obesity was significantly associated with a lower likelihood of having a live birth, but the risk differed according to women's age. A higher BMI might have a less-pronounced detrimental effect with increasing age.

Maternal overweight and obesity and its associated factors and outcomes in human immunodeficiency virus (HIV)-infected and HIV-uninfected black South African pregnant women.

This study aimed to investigate various variables between maternal overweight and/or obesity versus normal-weight pregnant black South African women living with and without human immunodeficiency virus (HIV). A cross-sectional study design was employed. A total of 200 pregnant women were enrolled in the study, categorized according to body mass index (BMI) (kg/m2 ) into two groups: (1) overweight/obese (≥25 kg/m2 ) (n=97); and (2) nonoverweight/nonobese (<25 kg/m2 ) (n=103), where 90 were HIV-infected and 110 were HIV-uninfected. The differences between the maternal BMI categories were assessed using Fisher's exact t-test and the χ2 test. Simple and multiple logistic regression analyses were used to determine factors associated with maternal overweight and obesity. Multiple logistic regression analysis showed that maternal age (odds ratio [OR]: 1.061; 95% confidence interval [CI] 1.008-1.117; p=0.023) and gestational age (OR: 1.121; 95% CI 1.005-1.251; p=0.041) were significantly associated with maternal overweight/obesity in both HIV-infected and HIV-uninfected. For maternal health outcomes, multiple logistic regression analysis showed that hypertensive disorders (OR: 0.273; 95% CI 0.124-0.601; p=0.001) and anemia (OR: 2.420; 95% CI 1.283-4.563; p=0.006) were significantly associated with maternal overweight/obesity in both HIV-infected and HIV-uninfected. The overweight/obese HIV-infected participants (OR: 0.233; 95% CI 0.075-0.717; p=0.011) had increased odds for developing hypertensive disorders compared to HIV-uninfected overweight/obese participants (OR: 0.471; 95% CI 0.172-1.291; p=0.143). Maternal overweight/obesity in both HIV-infected and HIV-uninfected pregnant black South African women was significantly associated with maternal age, gestational age, HPT disorders, and anemia. Maternal overweight/obesity decreased the odds for anemia, but increased the odds for the development of HPT disorders, especially in the HIV-infected pregnant women.

Maternal Pre-pregnancy Body Mass Index Categories and Infant Birth Outcomes: A Population-Based Study of 9 Million Mother-Infant Pairs.

Background and AimsInfant adverse birth outcomes have been suggested to contribute to neonatal morbidity and mortality and may cause long-term health consequences. Although evidence suggests maternal prepregnancy body mass index (BMI) categories associate with some birth outcomes, there is no consensus on these associations. We aimed to examine the associations of maternal prepregnancy BMI categories with a wide range of adverse birth outcomes.MethodsData were from a population-based retrospective cohort study of 9,282,486 eligible mother–infant pairs in the U.S. between 2016 and 2018. Maternal prepregnancy BMI was classified as: underweight (<18.5 kg/m2); normal weight (18.5–24.9 kg/m2); overweight (25.0–29.9 kg/m2); obesity grade 1 (30–34.9 kg/m2); obesity grade 2 (35.0–39.9 kg/m2); and obesity grade 3 (≥40 kg/m2). A total of six birth outcomes of the newborn included preterm birth, low birthweight, macrosomia, small for gestational age (SGA), large for gestational age (LGA), and low Apgar score (5-min score <7).ResultsMaternal prepregnancy overweight and obesity increased the likelihood of infant preterm birth, with odds ratios (ORs) (95% CIs) of 1.04 (1.04–1.05) for overweight, 1.18 (1.17–1.19) for obesity grade 1, 1.31 (1.29–1.32) for obesity grade 2, and 1.47 (1.45–1.48) for obesity grade 3, and also for prepregnancy underweight (OR = 1.32, 95% CI = 1.30–1.34) after adjusting for all potential covariates. Prepregnancy overweight and obesity were associated with higher odds of macrosomia, with ORs (95% CIs) of 1.53 (1.52–1.54) for overweight, 1.92 (1.90–1.93) for obesity grade 1, 2.33 (2.31–2.35) for obesity grade 2, and 2.87 (2.84–2.90) for obesity grade 3. Prepregnancy overweight and obesity was associated with higher odds of LGA, with ORs (95% CIs) of 1.58 (1.57–1.59) for overweight, 2.05 (2.03–2.06) for obesity grade 1, 2.54 (2.52–2.56) for obesity grade 2, and 3.17 (3.14–3.21) for obesity grade 3. Prepregnancy overweight and obesity were also associated with higher odds of low Apgar score, with ORs (95% CIs) of 1.12 (1.11–1.14) for overweight, 1.21 (1.19–1.23) for obesity grade 1, 1.34 (1.31–1.36) for obesity grade 2, and 1.55 (1.51–1.58) for obesity grade 3.ConclusionOur findings suggest maintaining or obtaining a healthy body weight for prepregnancy women could substantially reduce the likelihood of important infant adverse birth outcomes.

Relationship between pre-pregnancy maternal body mass index and infant weight trajectories in HIV-exposed and HIV-unexposed infants.

Maternal HIV and antiretroviral therapy (ART) exposure in utero may influence infant weight, but the contribution of maternal y body mass index (BMI) to early life overweight and obesity is not clear. To estimate associations between maternal BMI at entry to antenatal care (ANC) and infant weight through approximately 1year of age and to evaluate whether associations were modified by maternal HIV status, maternal HIV and viral load, breastfeeding intensity through 6months or timing of entry into ANC. We followed HIV-uninfected and -infected pregnant women initiating efavirenz-based ART from first antenatal visit through 12months postpartum. Infant weight was assessed via World Health Organization BMI and weight-for-length z-scores (WLZ) at 6weeks, 3, 6, 9 and 12months. We used multivariable linear mixed-effects models to estimate associations between maternal BMI and infant z-scores over time. In 861 HIV-uninfected infants (454 HIV-exposed; 407 HIV-unexposed), nearly 20% of infants were overweight or obese by 12months of age, regardless of HIV exposure status. In multivariable analyses, increasing maternal BMI category was positively associated with higher infant BMIZ and WLZ scores between 6weeks and 12months of age and did not differ by HIV exposure status. However, HIV-exposed infants had slightly lower BMIZ and WLZ trajectories through 12months of age, compared with HIV-unexposed infants across all maternal BMI categories. Differences in BMIZ and WLZ scores by HIV exposure were not explained by timing of entry into ANC or maternal viral load pre-ART initiation, but z-scores were slightly higher for HIV-exposed infants who were predominantly or exclusively versus partially breastfed. These findings suggest maternal BMI influences early infant weight gain, regardless of infant HIV exposure status. Intervention to reduce maternal BMI may help to address growing concerns about obesity among HIV-uninfected children.

Prognostic value of different maternal obesity phenotypes in predicting offspring obesity in a family-based cohort study

BackgroundParental weight is studied as an important determinant of childhood obesity; however, obesity-related metabolic abnormalities have been less considered as determinants of childhood obesity. This study aimed to investigate the association between maternal obesity phenotypes and incidence of obesity in their offspring.MethodsThis longitudinal study was conducted within the framework of the Tehran Lipid and Glucose Study. A total of 2151 non-obese children who had complete parental information were followed for incidence of obesity over a mean of 148.7 ± 34.7 months. Obesity in children was defined using the World Health Organization criteria. Maternal body mass index (BMI) was classified into three categories: normal weight, overweight and obese. Dysmetabolic status was considered as having metabolic syndrome or diabetes. Metabolic syndrome and diabetes were defined according to the Joint Interim Statement and American diabetes association criteria, respectively. Considering maternal BMI categories and metabolic status, six obesity phenotypes were defined as followed: 1) normal weight and normal metabolic status, 2) overweight and normal metabolic status, 3) obese and normal metabolic status, 4) normal weight and dysmetabolic status, 5) overweight and dysmetabolic status, and 6) obese and dysmetabolic status. The association between maternal obesity phenotypes and incidence of obesity in children was studied using Cox proportional regression hazard model.ResultsIn male offspring, the risk of incidence of obesity significantly increased in those with maternal obesity phenotypes including overweight/normal metabolic: 1.75(95% CI: 1.10–2.79), obese/normal metabolic: 2.60(95%CI: 1.51–4.48), overweight/dysmetabolic: 2.34(95%CI: 1.35–4.03) and obese/dysmetabolic: 3.21(95%CI: 1.94–5.03) compared to the normal weight/normal metabolic phenotype. Similarly, in girls, the risk of incidence of obesity significantly increased in offspring with maternal obesity phenotypes including overweight/normal metabolic: 2.39(95%CI: 1.46–3.90), obese/normal metabolic: 3.55(95%CI: 1.94–6.46), overweight/dysmetabolic: 1.92(95%CI: 1.04–3.52) and obese/dysmetabolic: 3.89(95%CI: 2.28–6.64) compared to normal weight/normal metabolic phenotype. However, maternal normal weight/dysmetabolic phenotype did not significantly change the risk of obesity in both male and female offspring.ConclusionExcept for normal weight/dysmetabolic phenotype, all maternal obesity phenotypes had significant prognostic values for incidence of offspring obesity with the highest risk for obese/dysmetabolic phenotype. This study provides valuable findings for identifying the first line target groups for planning interventions to prevent childhood obesity.

The Association between Maternal Body Mass Index and the Risk of Perinatal Depression.

The aim of this study was to evaluate whether the risk of perinatal depression is associated with body mass index (BMI) category. We performed a retrospective cohort study of women who completed an Edinburgh Postnatal Depression Scale (EPDS) questionnaire during the antepartum period at an integrated health system from January 2003 to May 2018. Risk of perinatal depression was defined as a score of ≥10 on the EPDS or an affirmative response to thoughts of self-harm. Risk of perinatal depression was compared by first trimester BMI category, defined as underweight (BMI: <18.5 kg/m2), normal weight (BMI: 18.5-24.9 kg/m2), overweight (BMI: 25.0-29.9 kg/m2), or obese (BMI: ≥30.0 kg/m2). Univariable analyses were performed using χ 2, Fisher's exact test, analysis of variance, Kruskal-Wallis, and Wilcoxon rank-sum tests as appropriate to evaluate the association between maternal BMI category, demographic and clinical characteristics, and risk of perinatal depression. Logistic multivariable regression models were performed to adjust for potential confounders identified as variables with p < 0.10 in univariable analysis. Our analysis included 3,420 obese women, 3,839 overweight women, 5,949 normal weight women, and 1,203 underweight women. The overall median gestational age at EPDS administration was 27 weeks (interquartile range: 23-29). Overweight and obese women were more likely to be non-Hispanic Black, Hispanic, multiparous, to have public insurance, prepregnancy diabetes, and chronic hypertension as compared with normal or underweight women (p < 0.001). In univariable analysis, the risk of perinatal depression was not significantly different among underweight (10.8%, odds ratio [OR]: 0.86, 95% confidence interval [CI]: 0.79-1.18) or overweight women (12%, OR: 0.96, 95% CI: 0.79-1.18); however, the risk was higher among obese women (14.7%, 95% CI: 1.21-1.55) compared with normal weight women (11.2%). In multivariable analysis, obesity remained associated with an increased risk of perinatal depression (adjusted OR: 1.19, 95% CI: 1.04-1.35). Obesity is associated with an increased risk of perinatal depression as compared with women of normal weight. · Maternal obesity is associated with an increased risk of perinatal depression.. · Maternal BMI is associated with increased risk of perinatal depression.. · Maternal obesity is an independent risk factor for perinatal depression..

The Role of Maternal Prepregnancy Body Mass Index in Breastfeeding Outcomes: A Systematic Review.

Background: The benefits of breastfeeding are well established in the literature. Barriers related to breastfeeding, such as maternal obesity, are also cited in the literature. Worldwide obesity rates in women of reproductive age are rising at an alarming pace. Previous research has attempted to study the relationship between maternal body mass index (BMI) and its effect on breastfeeding outcomes, but it is not clear what the role of maternal BMI category has on breastfeeding outcomes. Objectives: The objective of this review is to examine whether and how maternal BMI affects maternal breastfeeding outcomes such as intention, initiation, duration, and exclusivity. Methods: A systemic literature search through PubMed and Cumulative Index to Nursing and Allied Health Literature was conducted between January and May 2020, by using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 23 relevant articles were retrieved. Results: Of the 23 studies that assessed the relationship between maternal BMI and breastfeeding intention and other outcomes, only 4 found no differences in breastfeeding outcomes across BMI categories. Higher than normal maternal prepregnancy BMI has been found to be associated with poorer breastfeeding outcomes. Overweight and obese women are less likely to intend to breastfeed and initiate breastfeeding. They also have shorter breastfeeding durations and are less likely to exclusively breastfeed for any period compared with normal weight women. Conclusions: Breastfeeding rates across all BMI categories do not meet the recommended guidelines established by the World Health Organization and other public health agencies, and overweight and obese women have poorer breastfeeding outcomes. Overweight and obese women need additional support to initiate breastfeeding, and to breastfeed longer and exclusively. Targeted and well-designed interventions should be implemented early in the perinatal period to support this vulnerable population.

Role of maternal glucose metabolism in the association between maternal BMI and neonatal size and adiposity.

One potential mechanism by which maternal obesity impacts fetal growth is through hyperglycemia below the threshold for gestational diabetes. Data regarding which measures of maternal glucose metabolism mediate this association is sparse. The objectives of this study were to (i) quantify the associations of maternal pre-pregnancy body mass index (BMI) with neonatal size and adiposity and (ii) examine the role of markers of maternal glucose metabolism as mediators in these associations. This is a secondary analysis of 6,379 mother-infant dyads from the Hyperglycemia and Adverse Pregnancy Outcome cohort. Markers of glucose metabolism, including plasma glucose and c-peptide values, Stumvoll first-phase estimate, modified Matsuda index, and oral disposition index were measured and calculated from an oral glucose tolerance test (OGTT) between 24- and 32-weeks' gestation. We calculated the direct effect of maternal BMI category, measured at the time of the OGTT and regressed to estimate pre-pregnancy BMI, on neonatal (1) birth weight (BW), (2) fat mass (FM), (3) % body fat (BF%), and (4) sum of skinfold thickness (sSFT). We then calculated the indirect effect of BMI category on these measures through markers of glucose metabolism. Maternal BMI category was positively associated with neonatal BW, FM, BF%, and sSFT. Additionally, mothers who were overweight or obese had higher odds of delivering an infant with BW, FM, BF%, or sSFT >90th percentile. Fasting glucose and c-peptide values were the strongest mediators in the linear associations between maternal BMI category and neonatal size and adiposity. Maternal overweight and obesity were associated with higher odds of neonatal BW and adiposity >90th percentile. Fasting measures of glucose metabolism were the strongest mediators of these associations, suggesting that future studies should investigate whether incorporation of these markers in pregnant women with obesity may improve prediction of neonatal size and adiposity.

Maternal body mass index, smoking status and small for gestational age: an Australian retrospective cohort study

ObjectivesBoth maternal body mass index (BMI) and smoking during pregnancy have been associated with a range of adverse maternal and infant birth outcomes. This study aimed to identify whether these independent variables had an interacting relationship with small for gestational age in an Australian obstetric cohort. Study designA retrospective cohort design used data from the Birthing Outcomes System of a major tertiary hospital in Australia. MethodsA total of 14,487 singleton births between January 2008 and December 2013 were included in the analysis. Chi-squared tests and one-way analysis of variance were used for the comparison of categorical and continuous variables, respectively. Adjusted odds ratios (AORs) were calculated to determine the association of smoking status with the outcome variable of interest, and these are reported for each maternal BMI category. ResultsOf the 14,487 women, 716 (4.9%) were underweight (BMI ≤18 kg/m2), 7268 (50.2%) had healthy weight (BMI = 19–24 kg/m2), 3658 (25.3%) were overweight (BMI = 25–29 kg/m2), 1558 (10.8%) had class I obesity (BMI = 30–34 kg/m2), 711 (4.9%) had class II obesity (BMI = 35–39 kg/m2) and 576 (3.9%) had class III obesity (BMI = 40+ kg/m2). Of all women, 10.8% reported being current smokers, 82.0% reported to have never smoked and 4.0% reported to have stopped smoking during or before pregnancy. Smokers with a BMI ≥40 kg/m2 were 4.5 (AOR = 4.508; 95% confidence interval: 2.068–9.828) times more likely to give birth to a small-for-gestational-age infant than non-smokers within the same BMI category. This increased risk was not observed in women who ceased smoking before or during pregnancy. ConclusionsOur study supports the efficacy of antismoking policies within maternal public health. In addition, greater support with respect to smoking cessation is indicated for women during pregnancy with an elevated BMI.

Associations between maternal body mass index and diet composition with placental DNA methylation at term

IntroductionMaternal obesity and poor quality diets are associated with greater risk of obesity in offspring. Maternal diet and obesity influence placental gene expression and nutrient transport, but the impact of diet and obesity on global epigenetic changes in the placenta are poorly understood. We hypothesized that placental DNA methylation patterns are associated with maternal body mass index (BMI) and/or maternal diet composition. MethodsUsing reduced representation bisulfite sequencing (RRBS), we assessed genome scale DNA methylation of ~300,000 CpGs in 150 term placentas from normal weight mothers (n = 72) and overweight/obese mothers (n = 78). Maternal BMI was assessed before week 10 of gestation and maternal diet composition was assessed using 3-day food records at each trimester. ResultsIn multivariable linear regression models, maternal BMI category (normal weight or overweight/obese), BMI (kg/m2), and maternal saturated fat consumption (g/d) were associated (p < 0.0001) with methylation of 185, 103, and 302 CpGs, respectively. Of the 56 CpGs associated with both maternal BMI category and maternal BMI (p < 0.0001), GO analysis showed biological processes related to SREBP signaling, phospholipid transport, granulocyte differentiation, and RNA pol II transcription to be affected. Maternal saturated fat intake was associated with methylation of 302 CpGs (p < 0.0001). These genes were related to chromatin remodeling, IGF receptor, PI3K, and nitric oxide synthase signaling. DiscussionThese data suggest that placental DNA methylation status is associated with both maternal obesity and maternal saturated fat intake, possibly contributing to maternal obesity-associated changes in placental function.

Maternal urinary bisphenol A concentration and thyroid hormone levels of Chinese mothers and newborns by maternal body mass index.

Animal studies indicated that bisphenol A (BPA) exposure during pregnancy may disrupt thyroid function which is critical for fetal development. However, few epidemiological studies have examined this topic and the results were inconsistent. We aimed to evaluate whether prenatal BPA exposure is associated with thyroid hormone levels in Chinese mothers and newborns with stratification by maternal body mass index (BMI). BPA concentration were measured in urine samples collected from 555 women at late pregnancy. Maternal serum free thyroxin (FT4), thyroid-stimulating hormone (TSH) and thyroid peroxidase antibody (TPO-Ab) concentrations at the third trimester were abstracted from medical records. Cord serum-free triiodothyronine (FT3), FT4, TSH, and TPO-Ab levels were measured in 398 newborns. Prenatal urinary BPA was detected in 98.5% of mothers with a geometric mean of 1.32ng/mL (95% CI 1.17-1.49ng/mL). With each 10-fold increase in BPA concentrations, maternal log10_(TSH) mIU/L was 0.10 lowered (95% CI - 0.20, - 0.005, p < 0.05) among pre-pregnancy BMI>23kg/m2, with adjustment for maternal age, maternal education, gestation diabetes mellitus (GDM), husband smoking during pregnancy, parity, and gestational age at thyroid parameters measured, but no association was observed in pre-pregnancy BMI < 18.5, or 18.5-22.9kg/m2 stratum. No BPA-associated changes were observed in maternal FT4 level or odds of positive TPO-Ab in all BMI stratum. Also, no associations were observed between prenatal urinary BPA concentration and cord serum FT4, FT3, TSH levels, and odds of positive TPO-Ab in both male and female newborns among pre-pregnancy BMI < 18.5, 18.5-22.9 or>23kg/m2 stratum. In this study, prenatal urinary BPA concentration was associated with lower maternal TSH among women with overweight, but not associated with other maternal thyroid parameters or cord serum thyroid parameters across maternal BMI categories. More research on pregnant women and newborns cohort with BPA exposure are warranted.

Maternal Obesity and Risk of Cardiovascular Diseases in Offspring: Population-Based Cohort and Sibling-Controlled Studies

Background: Maternal overweight and obesity may increase offspring risks of adiposity, cardiovascular and metabolic diseases in childhood. We examined the associations between maternal overweight and obesity severity on risks of cardiovascular diseases (CVD) in offspring during childhood and early adulthood. Methods: In this population-based cohort study, we identified 2,412,100 non-malformed live singleton infants in the Swedish Medical Birth Register between 1992 and 2016. The diagnoses of CVD, pregnancy and neonatal complications were based on information from the nation-wide Medical Birth and Patient Registers. Multivariable Cox proportional hazards regression was used to estimate association between maternal body mass index (BMI) and CVD risk with adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). We further calculated the proportion of the association mediated through known consequences of obesity that also predicted CVD. To account for unmeasured genetic or environmental factors, we conducted sibling-controlled analyses. Findings: The overall incidence of CVD in offspring aged 1-25 years, was 0·75 per 10,000 child-years. Compared with offspring of normal weight mothers (BMI 18·5 to <25), aHRs (95% CIs) of CVD by maternal BMI categories were as follows: overweight (BMI 25 to <30), 1·07 (0·96, 1·19); obesity grade I (BMI 30 to <35), 1·11 (0·93-1·32); obesity grade II (BMI 35 to<40), 1·67 (1·28-2·19); and obesity grade III (BMI ≥40) 2·68 (1·85-3·89). Increasing maternal BMI was related to elevated risks of heart failure and cerebrovascular diseases in dose-response fashions (P for trend <0·001). Part of the observed association was mediated through asphyxia-related neonatal complications. The sibling-cohort analysis indicated a similar positive trend between maternal BMI and rates of CVD as the cohort analysis. Interpretations: Rates of CVD in offspring increase with maternal BMI in a dose-response manner. The association may be partly mediated through asphyxia-related neonatal complications. Funding Statement: The study was supported by grants from the Swedish Research Council for Health, Working Life and Welfare (grant No 2017-00134) and an unrestricted grant from Karolinska Institutet, Stockholm, Sweden (No. 2368/10-221 Distinguished Professor Award to Dr Cnattingius). Drs Razaz and Muraca are supported by a fellowship award from the Canadian Institutes of Health Research (CIHR). Declaration of Interests: All authors have no financial disclosures to state. Ethics Approval Statement: The study was approved by the Research Ethics Committee at Karolinska Institutet, Stockholm, Sweden (No. 2012/365-32 and No. 2017/1937-32).

Maternal obesity classes, preterm and post-term birth: a retrospective analysis of 479,864 births in England

BackgroundPreterm (< 37 weeks gestation) and post–term birth (≥42 weeks gestation) are associated with increased morbidity and mortality for mother and infant. Obesity (body mass index (BMI) ≥30 kg/m2) is increasing in women of reproductive age. Maternal obesity has been associated with adverse pregnancy outcomes including preterm and post–term birth. However, the effect sizes vary according to the subgroups of both maternal BMI and gestational age considered. The aim of this retrospective analysis was to determine the association between maternal obesity classes and gestational age at delivery.MethodsA secondary data analysis of 13 maternity units in England with information on 479,864 singleton live births between 1990 and 2007. BMI categories were: underweight (< 18.5 kg/m2), recommended weight (18.5–24.9 kg/m2), overweight (25.0–29.9 kg/m2) and obesity classes I (30.0–34.9 kg/m2), II (35.0–39.9 kg/m2), IIIa (40–49.9 kg/m2) and IIIb (≥50 kg/m2). Gestational age at delivery categories were: Gestational age at delivery (weeks): extreme preterm (20–27), very preterm (28–31), moderately preterm (32–36), early term (37, 38), full term (39–40), late term (41) and post–term (≥42). The adjusted odds of births in each gestational age category (compared to full-term birth), according to maternal BMI categories were estimated using multinomial logistic regression. Missing data were estimated using multiple imputation with chained equations.ResultsThere was a J-shaped association between the absolute risk of extreme, very and moderate preterm birth and BMI category, with the greatest effect size for extreme preterm. The absolute risk of post-term birth increased monotonically as BMI category increased. The largest effect sizes were observed for class IIIb obesity and extreme preterm birth (adjusted OR 2.80, 95% CI 1.31–5.98).ConclusionWomen with class IIIb obesity have the greatest risks for inadequate gestational age. Combining obesity classes does not accurately represent risks for many women as it overestimates the risk of all preterm and post-term categories for women with class I obesity, and underestimates the risk for women in all other obesity classes.

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.

The epidemiology of undernutrition and its determinants in children under five years in Ghana.

BackgroundUnderstanding the burden and contextual risk factors is critical for developing appropriate interventions to control undernutrition.MethodsThis study used data from the 2014 Ghana Demographic and Health Survey to estimate the prevalence of underweight, stunting, and wasting. Single multiple logistic regressions were used to identify the factors associated with underweight, wasting and stunting. The study involved 2720 children aged 0–59 months old and mother pairs. All analyses were done in STATA/IC version 15.0. Statistical significance was set at p<0.05.ResultsThe prevalence of underweight, wasting and stunting were 10.4%, 5.3%, and 18.4% respectively. The age of the child was associated with underweight, wasting and stunting, whereas the sex was associated with wasting and stunting. Normal or overweight/obese maternal body mass index category, high woman’s autonomy and middle-class wealth index were associated with a lower odds of undernutrition. The factors that were associated with a higher odds of child undernutrition included: low birth weight (<2.5 kg), minimum dietary diversity score (MDDS), a higher (≥4th) birth order number of child, primary educational level of husband/partner and domicile in the northern region of Ghana.ConclusionThere is still a high burden of child undernutrition in Ghana. The age, sex, birth weight, birth order and the MDDS of the child were the immediate factors associated with child undernutrition. The intermediate factors that were associated with child undernutrition were mainly maternal related factors and included maternal nutritional status and autonomy. Distal level factors which were associated with a higher odds of child undernutrition were the wealth index of the household, paternal educational status and region of residence. We recommend that interventions and policies for undernutrition should address socioeconomic inequalities at the community level while factoring in women empowerment programmes.

The relationship between maternal body mass index and pregnancy outcomes in twin compared with singleton pregnancies.

Women with twins have an a priori increased risk for many of the complications associated with maternal obesity. Thus, the impact of maternal obesity in twins may differ from that reported in singletons. In addition, given the increased metabolic demands in twin pregnancies, the impact of maternal underweight may be greater in twin compared with singleton gestations. Our objective was to test the hypothesis that the relationship between maternal pre-pregnancy body mass index (BMI) and adverse pregnancy outcomes differ between twin and singleton gestations. This was a retrospective population-based study of all women who had a singleton or twin hospital birth in Ontario, Canada, between April 2012 and March 2016. Data were obtained from the Better Outcomes Registry & Network (BORN) Ontario. The relationship between maternal BMI category and pregnancy complications was assessed separately in twin and singleton gestations. The primary outcome was a composite variable that included any of the following complications: preeclampsia, gestational diabetes, or preterm birth before 320/7 weeks. Relative risk (aRR) and 95% confidence intervals (CI) for adverse outcomes for each BMI category as defined by WHO (using normal weight category as reference) were generated using modified Poisson regression, adjusting for maternal age, nulliparity, smoking, previous preterm birth, and fetal sex. A total of 487,870 women with singleton (n = 480,010) and twin (n = 7860) pregnancies met the inclusion criteria. The risk of the composite primary outcome, preeclampsia, gestational diabetes, and cesarean delivery increased with high maternal BMI in both singleton and twin gestations, but these associations were weaker in twin compared with singleton gestations (association of BMI ≥ 40.0 kg/m2 with primary outcome: aRR = 3.10, 95%-CI 2.96-3.24 in singletons compared with aRR = 1.74, 95%-CI 1.37-2.20 in twins). In singleton pregnancies the risk of preterm birth at < 320/7 weeks increased with maternal BMI, mainly due to an increased risk of provider-initiated preterm birth. In twin gestations, however, underweight (but not overweight or obesity) was associated with the greatest risk of preterm birth at < 32 weeks (aRR 1.67, 95%-CI 1.17-2.37), mainly due to an increased risk of spontaneous preterm birth (aRR 2.10, 95%-CI 1.44-3.08). In healthy women with twin pregnancies, underweight is associated with the greatest risk for preterm birth, while the association of maternal obesity with adverse pregnancy outcomes is weaker than that observed in singletons.