Update on Prepregnancy Maternal Obesity: Birth Defects and Childhood Outcomes

Impact of pregestational obesity on perinatal complications: update in a Latin American cohort

OBJECTIVES

While the association between pregestational obesity and perinatal complications has been established, it is necessary to update the current understanding of its impact on maternal and foetal health due to its growing prevalence. Thus, this study aimed to investigate the association between pregestational obesity with the leading perinatal complications during the last 6 years.

STUDY DESIGN

A cross-sectional study was performed in San Felipe, Chile. Anonymised data of 11,197 deliveries that occurred between 2015 and 2021 were included.

METHODS

Pregestational body mass index was defined according to the World Health Organisation during the first trimester of pregnancy. The association between pregestational obesity and perinatal complications was analysed by calculating the odds ratio (OR), which was adjusted for confounding variables. Statistical differences were considered with a P-value of <0.05.

RESULTS

The prevalence of pregestational obesity was 30.1%. Pregestational obesity was related to a high incidence of perinatal complications (≥3 complications; P < 0.0001). The main perinatal complications were caesarean section, large for gestational age (LGA), gestational diabetes (GD), macrosomia, hypertensive disorders of pregnancy (HDP), premature rupture of membranes (PROM), intrauterine growth restriction, and failed induction. Pregestational obesity was shown to be a risk factor for macrosomia (OR: 2.3 [95% confidence interval {95% CI}: 2.0-2.8]), GD (OR: 1.9 [95% CI: 1.6-2.1]), HDP (OR: 1.8 [95% CI: 1.5-2.1]), LGA (OR: 1.6 [95% CI: 1.5-1.8]), failed induction (OR: 1.4 [95% CI: 1.0-1.8]), PROM (OR: 1.3 [95% CI: 1.1-1.6]), and caesarean section (OR: 1.3 [95% CI: 1.2-1.4]).

CONCLUSIONS

Pregestational obesity has been shown to be a critical risk factor for the main perinatal complications in the study population. Pregestational advice is imperative not only in preventing pregestational obesity but also in the mitigation of critical perinatal complications once they arise.

Obesity in prenatal medicine: a game changer?

Obesity is recognized by the World Health Organization (WHO) as a disease in its own right. Moreover, obesity is an increasingly concerning public health issue across the world and its prevalence is rising amongst women of reproductive age. The fertility of over-weight and obese women is reduced and they experience a higher rate of miscarriage. In pregnant women obesity not only increases the risk of antenatal complications, such as preeclampsia and gestational diabetes, but also fetal abnormalities, and consequently the overall feto-maternal mortality. Ultrasound is one of the most valuable methods to predict and evaluate pregnancy complications. However, in overweight and obese pregnant women, the ultrasound examination is met with several challenges, mainly due to an impaired acoustic window. Overall obesity in pregnancy poses special challenges and constraints to the antenatal care and increases the rate of pregnancy complications, as well as complications later in life for the mother and child.

Evaluation of subclinical atherosclerosis and cardiac functions in children of mothers with gestational diabetes and maternal obesity

BACKGROUND AND AIMS

We aimed to evaluate the effects of maternal obesity or gestational diabetes on body composition, lipid, and glucose metabolism, arterial morphology, and functions in children, and to investigate these effects in terms of cardiometabolic diseases.

METHODS

The study group was composed of 48 children who had a history of gestational diabetes or maternal obesity, and the control group was composed of 33 children. Echocardiographic assessments were performed. Socio-economic status and education level of mothers were obtained.

RESULTS

In the study group, carotid intima-media thickness, epicardial adipose tissue thickness, and arterial stiffness values were found to be significantly higher compared to the control group (p < 0.001, p < 0.001, p = 0.003, respectively), while arterial distensibility and arterial strain values were found to be significantly lower (p = 0.003, p = 0.008, respectively). Among the children who had similar body mass index in both groups, children in the study group had higher carotid intima-media thickness and epicardial adipose tissue thickness values. Arterial stiffness values were significantly reduced (p = 0.028) and arterial distensibility and strain values were significantly increased (p = 0.039, p = 0.033, respectively) in the children whose mothers had gestational diabetes and high socio-economic status. Left ventricular mass and left ventricular end-diastolic internal thickness were found to be significantly increased in the children who had obese and unemployed mothers (p = 0.04, p = 0.03, respectively).

CONCLUSION

Low socio-economic status was found to be associated with increased maternal obesity and gestational diabetes. Poor socio-economic status, poor glycaemic control and being overweight during pregnancy indicate negative cardiometabolic outcomes for children in the long term.

Association Between Maternal Factors and Risk of Congenital Heart Disease in Offspring: A Systematic Review and Meta-Analysis

INTRODUCTION

This study aimed to summarize the evidence describing the relationship between maternal factors during gestation and risk of congenital heart disease (CHD) in offspring.

METHODS

PubMed, EMBASE, and the Cochrane Library were searched for potentially relevant reports from inception to May 2021. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) calculated by the random-effects model were used to evaluate the association between maternal factors and CHD risk.

RESULTS

There was a significant association between CHD risk and obesity in pregnancy (OR 1.29, 95% CI 1.22-1.37; P < 0.001), smoking in pregnancy (OR 1.16, 95% CI 1.07-1.25; P < 0.001), maternal diabetes (OR 2.65, 95% CI 2.20-3.19; P < 0.001), and exposure of pregnant women to organic solvents (OR 1.82, 95% CI 1.23-2.70; P = 0.003). No correlations were revealed between CHD susceptibility and advanced maternal age (OR 1.04, 95% CI 0.96-1.12; P = 0.328), underweight (OR 1.02, 95% CI 0.96-1.08; P = 0.519), alcohol intake in pregnancy (OR 1.08, 95% CI 0.95-1.22; P = 0.251), coffee intake (OR 1.18, 95% CI 0.97-1.44; P = 0.105), and exposure to irradiation (OR 1.80, 95% CI 0.85-3.80; P = 0.125).

DISCUSSION

Maternal factors including maternal obesity, smoking in pregnancy, maternal diabetes and exposure to organic solvents might predispose the offspring to CHD risk.

Prepregnancy overweight and obesity as risk factors for birth defects: a cross-sectional study over a 30-year period

Overweight and obesity are public health problems worldwide despite being modifiable conditions. The association between birth defects and pregestational maternal body mass index is not entirely clear. We aimed to assess the prevalence and estimate the risk of birth defects related to pregestational body mass index and other maternal factors. We explored a 30-year time series database in a cross-section study. We analysed 40,217 cases, among them 2.8% had birth defects. Bivariate analysis showed a higher prevalence of birth defects with increased pre-pregnancy body mass index and in extremes of maternal age, white skin colour, and primiparity. Multivariable logistic regression showed a higher chance of birth defects in women with pre-pregnancy overweight/obesity (OR:1.19 [CI95%:1.01-1.41]), maternal age ≥ 40 years (OR:1.68 [CI95%:1.11-2.54]), and white skin colour (OR:1.44 [CI95%:1.19-1.75]). Maternal weight is a modifiable risk factor that must be considered and addressed in preconception counselling to minimise possible deleterious effects on embryogenesis.IMPACT STATEMENTWhat is already known on this subject? Previous studies have linked some maternal factors with birth defects. However, the association with prepregnancy maternal body mass index is not clear.What do the results of this study add? Our findings provide support for the association of prepregnancy maternal overweight and obesity with birth defects and highlight that BMI is a modified risk factor.What are the implications of these findings for clinical practice and/or further research? Maternal body mass index is a modifiable risk factor, highlighting the importance of preconception counselling for the prevention and possible reduction of factors that increase the risk of birth defects.

Markers of Maternal Insulin Resistance and Lipid Ratios Measured in Early Pregnancy Are Related to Adverse Fetomaternal Outcomes in Women Treated for Hyperglycemia Detected in Early Pregnancy-Data from a Retrospective Cohort Study

Background: Hyperglycemia detected in early pregnancy is still inadequately studied as a risk factor for adverse maternal and neonatal outcomes. Methods: a retrospective study of a cohort of N = 193 women in singleton pregnancies with hyperglycemia diagnosed before the 20th gestational week (GW). Results: characteristics of the study group: GW at the diagnosis: 12.0 (9.0; 15.0), diabetes diagnosed in early pregnancy (eDiP): 21%, insulin-therapy required: 61.8%, gestational hypertension/preeclampsia: 7.7%, premature delivery: 9.2%, composite adverse neonatal outcome: 59.2%, high (LGA) birth weight/low (SGA) birth weight according to the WHO growth charts: 24.2%/9.2%, respectively. Women with eDiP have lower eGDR, a higher TAG/HDL ratio, and a higher atherogenic index of plasma (AIP) compared to women with gestational diabetes diagnosed in early pregnancy—eGDM (9.33 ± 1.56 vs. 7.92 ± 2.54, p = 0.007, 1.06 ± 0.78, vs. 1.25 ± 0.68, p = 0.020, and −0.06 ± 0.25 vs. 0.04 ± 0.23 p = 0.021, respectively). NonHDL/HDL cholesterol ratio > 2.6, and AIP > 0.24 total/HDL cholesterol ratio > 4.5 significantly predicted metabolic adverse neonatal outcome (hypoglycemia and/or hyperbilirubinemia)—OR (95% CI): 4.62 (1.35; 15.79), 3.60 (1.04; 12.48), 8.75 (1.02; 74.83), respectively. Conclusions: 1, Hyperglycemia diagnosed in early pregnancy coexists with a lipid profile suggestive of insulin resistance. 2, Lipid-related markers of cardiometabolic risk measured in early pregnancy can be useful tools in assessment of fetomaternal risk in high-risk populations. 3, Women with eDiP present a more severe insulin resistance phenotype than those with eGDM.

Disparities in Risks of Inadequate and Excessive Intake of Micronutrients during Pregnancy

BACKGROUND

Inadequate or excessive intake of micronutrients in pregnancy has potential to negatively impact maternal/offspring health outcomes.

OBJECTIVE

The aim was to compare risks of inadequate or excessive micronutrient intake in diverse females with singleton pregnancies by strata of maternal age, race/ethnicity, education, and prepregnancy BMI.

METHODS

Fifteen observational cohorts in the US Environmental influences on Child Health Outcomes (ECHO) Consortium assessed participant dietary intake with 24-h dietary recalls (n = 1910) or food-frequency questionnaires (n = 7891) from 1999-2019. We compared the distributions of usual intake of 19 micronutrients from food alone (15 cohorts; n = 9801) and food plus dietary supplements (10 cohorts with supplement data; n = 7082) to estimate the proportion with usual daily intakes below their age-specific daily Estimated Average Requirement (EAR), above their Adequate Intake (AI), and above their Tolerable Upper Intake Level (UL), overall and within sociodemographic and anthropometric subgroups.

RESULTS

Risk of inadequate intake from food alone ranged from 0% to 87%, depending on the micronutrient and assessment methodology. When dietary supplements were included, some women were below the EAR for vitamin D (20-38%), vitamin E (17-22%), and magnesium (39-41%); some women were above the AI for vitamin K (63-75%), choline (7%), and potassium (37-53%); and some were above the UL for folic acid (32-51%), iron (39-40%), and zinc (19-20%). Highest risks for inadequate intakes were observed among participants with age 14-18 y (6 nutrients), non-White race or Hispanic ethnicity (10 nutrients), less than a high school education (9 nutrients), or obesity (9 nutrients).

CONCLUSIONS

Improved diet quality is needed for most pregnant females. Even with dietary supplement use, >20% of participants were at risk of inadequate intake of ≥1 micronutrients, especially in some population subgroups. Pregnancy may be a window of opportunity to address disparities in micronutrient intake that could contribute to intergenerational health inequalities.

Improving translational relevance: The need for combined exposure models for studying prenatal adversity

Prenatal environmental adversity is a risk factor for neurodevelopmental disorders (NDDs), with the neuroimmune environment proposed to play a role in this risk. Adverse maternal exposures are associated with cognitive consequences in the offspring that are characteristics of NDDs and simultaneous neuroimmune changes that may underlie NDD risk. In both animal models and human studies the association between prenatal environmental exposure and NDD risk has been shown to be complex. Maternal overnutrition/obesity and opioid use are two different examples of complex exposure epidemics, each with their own unique comorbidities. This review will examine maternal obesity and maternal opioid use separately, illustrating the pervasive comorbidities with each exposure to argue a need for animal models of compound prenatal exposures. Many of these comorbidities can impact neuroimmune function, warranting systematic investigation of combined exposures to begin to understand this complexity. While traditional approaches in animal models have focused on modeling a single prenatal exposure or second exposure later in life, a translational approach would begin to incorporate the most prevalent co-occurring prenatal exposures. Long term follow-up in humans is extremely challenging, so animal models can provide timely insight into neurodevelopmental consequences of complex prenatal exposures. Animal models that represent this translational context of comorbid exposures behind maternal obesity or comorbid exposures behind maternal opioid use may reveal potential synergistic neuroimmune interactions that contribute to cognitive consequences and NDD risk. Finally, translational co-exposure models can identify concerning exposure combinations to guide treatment in complex cases, and identify high risk children starting in the prenatal period where early interventions improve prognosis.

The Risk of Congenital Anomalies by Fertility Treatment Modality

Importance

Up to 4% of all births in developed nations involve assisted reproductive technology (ART), along with other fertility treatment modalities. Thus, ART pregnancies constitute an important epidemiologic population with a known increased risk of congenital anomalies. In this review, we summarize current fertility treatment modalities and their associated risk of congenital anomalies.

Objective

To review the risk of birth defects among pregnancies conceived with ART and other fertility treatments.

Evidence Acquisition

Articles were obtained from PubMed and the American College of Obstetricians and Gynecologists and American Society of Reproductive Medicine committee opinions.

Results

In vitro fertilization has been associated with a 25% to 50% increased risk of birth defects, including abnormalities of these organ systems: cardiovascular (25%-40% of anomalies), genitourinary (10%-60%), gastrointestinal (10%-20%), and musculoskeletal (10%-35%). Although the data are mixed, intracytoplasmic sperm injection has also been found to be associated with an increased risk of defects, particularly hypospadias, when compared with conventional in vitro fertilization. The risk among fresh versus frozen cycles and cleavage stage versus blastocyst transfers remains uncertain. There appears to be no significant added risk with preimplantation genetic testing, although more studies are needed. Ovulation induction with oral agents appears safe and not associated with an increased risk of anomalies. Oocyte cryopreservation also appears safe, but the data are still limited, requiring future investigation.

Conclusions and Relevance

While the relative risk of birth defects among ART pregnancies is increased when compared with spontaneous conceptions, the absolute risk remains low. There are no standard screening recommendations for ART pregnancies. Per the American College of Obstetricians and Gynecologists, patients who have undergone ART should be counseled regarding the risk of birth defects and available antenatal evaluation, including fetal echocardiogram and detailed ultrasound evaluation.

Prevention of Teratogenesis in Pregnancies of Obese Rats by Vitamin E Supplementation

Congenital malformations are a common adverse outcome in pregnancies complicated by pregestational obesity, although the underlying mechanisms are still unrevealed. Our aim was to study the effect of oxidative stress in obesity-induced teratogenesis. Wistar rats were fed a high-fat diet for 13 weeks, with (OE group) or without (O group) vitamin E supplementation. Then, rats were mated and sacrificed at day 11.5 of gestation. Embryos from O dams presented a 25.9 ± 3.5% rate of malformations (vs. 8.7 ± 3.4% in C rats), which was reduced in the OE group (11.5 ± 2.3%). Pregestational obesity induced hepatic protein and DNA oxidation and a decline in antioxidant enzymes. Importantly, glutathione content was also decreased, limiting the availability of this antioxidant in the embryos. Vitamin E supplementation efficiently maintained glutathione levels in the obese mothers, which could be used in their embryos to prevent oxidation-induced malformations. To test the effect of decreasing glutathione levels alone in a cell culture model of neuroepithelium, murine embryonic stem cells (ESC) were induced to form neuronal precursors and glutathione synthesis was inhibited with the gamma–glutamylcysteine synthesis inhibitor, buthionine sulfoximine (BSO). BSO inhibited the expression of Pax3, a gene required for neural tube closure that is also inhibited by oxidative stress. Taken together, our data indicate that obesity causes malformations through the depletion of maternal glutathione, thereby decreasing glutathione-dependent free radical scavenging in embryos, which can be prevented by vitamin E supplementation.

SIRT1 regulates sphingolipid metabolism and neural differentiation of mouse embryonic stem cells through c-Myc-SMPDL3B

Sphingolipids are important structural components of cell membranes and prominent signaling molecules controlling cell growth, differentiation, and apoptosis. Sphingolipids are particularly abundant in the brain, and defects in sphingolipid degradation are associated with several human neurodegenerative diseases. However, molecular mechanisms governing sphingolipid metabolism remain unclear. Here, we report that sphingolipid degradation is under transcriptional control of SIRT1, a highly conserved mammalian NAD⁺-dependent protein deacetylase, in mouse embryonic stem cells (mESCs). Deletion of SIRT1 results in accumulation of sphingomyelin in mESCs, primarily due to reduction of SMPDL3B, a GPI-anchored plasma membrane bound sphingomyelin phosphodiesterase. Mechanistically, SIRT1 regulates transcription of Smpdl3b through c-Myc. Functionally, SIRT1 deficiency-induced accumulation of sphingomyelin increases membrane fluidity and impairs neural differentiation in vitro and in vivo. Our findings discover a key regulatory mechanism for sphingolipid homeostasis and neural differentiation, further imply that pharmacological manipulation of SIRT1-mediated sphingomyelin degradation might be beneficial for treatment of human neurological diseases.

All cells in the brain start life as stem cells which are yet to have a defined role in the body. A wide range of molecules and chemical signals guide stem cells towards a neuronal fate, including a group of molecules called sphingolipids. These molecules sit in the membrane surrounding the cell and play a pivotal role in a number of processes which help keep the neuronal cell healthy.

Various enzymes work together to break down sphingolipids and remove them from the membrane. Defects in these enzymes can result in excess levels of sphingolipids, which can lead to neurodegenerative diseases, such as Alzheimer’s, Parkinson’s and Huntington’s disease. But how these enzymes are used and controlled during neuronal development is still somewhat of a mystery. To help answer this question, Fan et al. studied an enzyme called SIRT1 which has been shown to alleviate symptoms in animal models of neurodegenerative diseases.

Stem cells were extracted from a mouse embryo lacking the gene for SIRT1 and cultured in the laboratory. These faulty cells were found to have superfluous amounts of sphingolipids, which made their membranes more fluid and reduced their ability to develop into neuronal cells. Further investigation revealed that SIRT1 regulates the degradation of sphingolipids by promoting the production of another enzyme called SMPDL3B. Fan et al. also found that when female mice were fed a high-fat diet, this caused sphingolipids to accumulate in their embryos which lacked the gene for SIRT1; this, in turn, impaired the neural development of their offspring.

These findings suggest that targeting SIRT1 may offer new strategies for treating neurological diseases. The discovery that embryos deficient in SIRT1 are sensitive to high-fat diets implies that activating this enzyme might attenuate some of the neonatal complications associated with maternal obesity.

Aim and Design of pREGnant, the Dutch Pregnancy Drug Register

Information on the safety of medication use during pregnancy and breastfeeding is scarce, yet use of medication among pregnant and breastfeeding women is widespread. The pREGnant, the Dutch Pregnancy Drug Register, was set up to obtain insight into medication use among pregnant and breastfeeding women and potential effects on maternal and fetal/infant health. The systematically documented, good quality data on medication use during pregnancy and lactation in pREGnant will be used in signal detection, epidemiologic studies and counseling of healthcare providers and patients. The register has a prospective cohort design. The population is derived from pregnant women throughout the Netherlands. Data collection started in April 2014 and enrollment of women is continuous and is characterized by a relative high proportion of women born in the Netherlands with a high education compared with the general Dutch pregnant population. Data on current pregnancy, obstetric history, maternal lifestyle, health and medication use, delivery, and infant health are collected through web-based questionnaires completed by the participating women (three times during pregnancy and three times during the infant’s first year of life). If permission is given, the self-reported data can be complemented with information retrieved from Perined, the perinatal registry of the Netherlands, and from obstetric and medical records, and/or pharmacy records. Here, we provide detailed information on the design of the pREGnant, the Dutch Pregnancy Drug Register, as well as descriptive information on characteristics of the participants so far. Currently, steps are being taken to implement the register on a large scale in the Netherlands.

Maternal periconceptional body mass index and risk for neural tube defects: results from a large cohort study in China

Background: Case-control studies have consistently suggested an association between pre- or periconceptional maternal obesity and an increased risk for neural tube defects (NTDs). Few studies have examined the association between body mass index (BMI) and NTDs using measured weight and height. We examined this association in a large cohort study in China.Methods: We used data from a large population-based cohort study established to evaluate the effectiveness of folic acid supplementation to prevent NTDs in China. BMI was computed using maternal weight and height measured before pregnancy or during early pregnancy. External birth defects were identified through a unique birth defects surveillance system. We estimated the birth prevalence and prevalence odds ratios (POR) for NTDs by Chinese BMI categories, controlling for potential confounders.Results: Our study population included a total of 194,844 women. We observed significantly elevated risk for spina bifida (adjusted POR = 5.4, 95% CI: 1.3-22.5) among children born to obese compared to normal weight women. Among women who took folic acid supplements, the adjusted POR for spina bifida among obese women was 10.0 (95% CI: 2.3-42.6) compared to pill users who were of normal weight. Borderline significantly elevated risk was observed for anencephaly (adjusted POR = 1.8; 95% CI: 1.0-3.2) among children born to underweight compared to normal weight women.Conclusions: Our findings suggest that maternal periconceptional obesity may be associated with an increased risk for spina bifida. Maternal underweight may be associated with increased risk for anencephaly.

Maternal Obesity as a Risk Factor for the Development of Total Anomalous Pulmonary Venous Connection in Their Offspring

The incidence of total anomalous pulmonary venous connection (TAPVC) in the Caucasian population is 2.5/100,000 live births (LB), and the incidence in the Hispanic population is 19.8/100,000 LB. Without knowing the exact etiology for the development of congenital heart disease, our objective was to determine the maternal factors associated with the development of TAPVC.

METHODS

55 mother-child binomials with isolated TAPVC (group I) and 152 healthy mother-child binomials (group II) were included. Both groups had no maternal history of addiction, pre-eclampsia, or type 1, 2 or gestational diabetes mellitus. Complete clinical histories were obtained for the women in both groups and perinatal and birth data were recorded. In addition, genealogies across three generations were constructed to determine affected first- or second-degree relatives with complex congenital heart disease.

RESULTS

Among the maternal characteristics analyzed, women in group I had a higher number of pregnancies before gestation of the index case (p = <0.05), and the Body Mass Index (BMI) before pregnancy was higher compared to Group II (p < 0.05), with an adjusted risk of OR = 3.6 (p = 0.011). The family history showed a higher prevalence in the group of patients with TAPVC compared to healthy children (p < 0.05).

CONCLUSION

Maternal obesity before pregnancy is a risk factor for the development of CATVP in children in the Mexican population.