Female fetus is associated with greater maternal insulin resistance in pregnancy

Association between fetal sex and metabolic syndrome in women aged 40 years and older: the REACTION study

Introduction

This study aimed to investigate whether fetal sex influences the risk of metabolic syndrome (MetS) in women in China.

Materials and Methods

A cohort of 3,758 Chinese women, each having given birth to only one child and aged 40 years or older, was included in the study. Registry data on all pregnancies and miscarriages were collected for each participant. This retrospective cohort study aimed to determine whether fetal sex was associated with metabolic syndrome. MetS was defined as meeting at least three of the following five criteria: impaired insulin metabolism, reduced glucose tolerance, hypertension, dyslipidemia, and large waist circumference.

Results

Among the 3,758 women aged 40 years and older in Luzhou City, 1,018 (27.1%) developed MetS. Mothers who had carried a male fetus had higher triglyceride (TG) and total cholesterol (TC) levels and a greater prevalence of diabetes than those who had carried a female fetus (P < 0.05). Although the incidence of MetS was higher in women who had carried a male fetus than in those who had carried a female fetus, the difference was not statistically significant (P > 0.05). Notably, MetS was significantly less prevalent in premenopausal women than in postmenopausal women, irrespective of fetal sex (P < 0.05). In the postmenopausal subgroup, the incidence of MetS was significantly higher in women who had carried a male fetus compared to those who had carried a female fetus (P < 0.05).

Conclusions

Our study found no significant association between fetal sex and MetS in Chinese women aged 40 years and older. However, among postmenopausal women, the incidence of MetS was significantly higher in those who had carried a male fetus. Greater attention should be given to postmenopausal women with a history of carrying a male fetus, and early preventive measures should be implemented to reduce the risk of related chronic diseases.

Untreated women with first trimester fasting glycaemia 92-125 mg/dL and risk of gestational diabetes mellitus in the 24-28th week OGTT: prevalence and predictors

INTRODUCTION

Women with first trimester fasting glycaemia (FTFG) 92-125 mg/dL may present with normal 24-28th week OGTT (2T-OGTT). Predictors of persistent hyperglycaemia were scarcely investigated. We studied the prevalence and predictors of gestational diabetes mellitus (GDM) in the 2T-OGTT in women with untreated elevated FTFG.

METHODS

Retrospective study of women from the national GDM registry with FTFG between 92 and 125 mg/dL that had passed unnoticed and untreated until the 2T-OGTT.

PRIMARY ENDPOINT

GDM in the 2T-OGTT. Women with and without GDM were compared. A multivariate logistic regression analysis was used to study GDM predictors. Included variables: FTFG, newborn sex, and known GDM risk factors.

RESULTS

We studied 407 women. 82% (82.1%) of women had a positive 2T-OGTT. Women with abnormal 2T-OGTT were older, had higher BMI, and more often carried female newborns. There were no differences concerning other known GDM risk factors, FTFG, and obstetric or neonatal complications. Age, BMI and newborn sex were associated with higher risk of GDM independently of other GDM risk factors or FTFG. Per 1 year of age and 1 kg/m2 of BMI, the OR (95%CI) for this association were 1.10 (1.05-1.16) and 1.07 (1.02-1.12), respectively. Alternatively, women older than 35 years or with a BMI ≥ 30Kg/m2 had an OR of 2.53 (1.30-4.90) and 2.20 (1.22-3.98), respectively. Women with male newborns had approximately half the risk of abnormal 2T-OGTT [OR 0.51 (0.30-0.87)].

CONCLUSIONS

Nearly 18% of women with FTFG between 92 and 125 mg/dL had a normal 2T-OGTT. Older age, higher BMI, and female newborns were associated with increased risk of abnormal 2T-OGTT.

The influence of fetal sex on antenatal maternal glucose and insulin dynamics

The 'Developmental Origins of Health and Disease' (DOHaD) hypothesis postulates that exposures during critical periods of development and growth, including maternal hyperglycemia, can have significant consequences for short- and long-term health in offspring. The influence of fetal status on maternal (patho)physiology is less well understood but gaining attention. Fetal sex specifically may be an independent risk factor for a range of adverse pregnancy outcomes, including increased gestational diabetes mellitus (GDM) frequency with male fetuses in multi-ethnic populations. Fetal sex has been thought to modulate maternal glucose metabolism, including insulin dynamics, through complex genetic and hormonal interactions. Mechanisms have not been fully elucidated, however, but may relate to sexual dimorphism in maternal-fetal-placental interactions. We review current evidence on the potential influence of fetal sex on maternal glucose and insulin dynamics, and fetal outcomes.

Exposure to alkylphenols during early pregnancy and the risk of gestational diabetes mellitus: Fetal sex-specific effects

Alkylphenols (APs) may cause gestational diabetes mellitus (GDM) in pregnant women by impairing glucose metabolism through endocrine disruption. However, the current literature has limited epidemiological evidence on the association between APs exposure and the risk of GDM, especially the lack of evidence on joint exposure. Thus, we evaluated the effect of exposure to APs during early pregnancy on the risk of GDM. The study involved 2035 pregnant women from Guangxi Zhuang Birth Cohort (GZBC) in China. Poisson regression model, restricted cubic spline (RCS), Bayesian kernel machine regression (BKMR), and quantile g-computation (Qgcomp) were conducted to evaluate the effects of serum APs levels on the risk of GDM in pregnant women. For each Ln-unit increase in the serum nonylphenol (NP) of pregnant women, the adjusted relative risk (RR) for GDM risk was 1.12 (95 % CI: 1.00, 1.24). After sex stratification, the effect was more pronounced among pregnant women carrying female fetuses（RR=1.22; 95 % CI: 1.09, 1.38). The serum 4-t-octylphenol (4-T-OP) of the medium-exposure (adjusted RR = 3.25: 95 % CI: 1.30, 8.12) and high-exposure groups (adjusted RR = 2.90: 95 % CI: 1.15, 7.31) were related to a significantly increased risk of GDM in pregnant women carrying female fetuses only when compared to the low-exposure group. A reverse U-shaped nonlinear association was found between 4-n-octylphenol (4-N-OP) and 4-n-nonylphenol (4-N-NP) concentrations and GDM risk, and it was more susceptible in pregnant women carrying female fetuses. The Qgcomp and BKMR models showed that exposure to APs mixtures was correlated with an elevated risk of GDM in pregnant women carrying female fetuses (adjusted OR = 1.90: 95 % CI: 1.07, 3.38). Exposure to APs during early pregnancy may have potential fetal sex-specific effects on the risk of GDM, with pregnant women carrying female fetuses being more susceptible.

Fetal sex effects on maternal health can now be tested via randomization: A first-in-class illustration in cows on glucoregulatory outcomes

BACKGROUND

The maternal-offspring relationship, such as whether fetal sex influences maternal health, is essential to explore to advance prenatal and maternal health. While associations exist between fetal sex and maternal health outcomes, it is unclear whether these reflect a causal relationship.

OBJECTIVE

To demonstrate that fetal sex can be randomly assigned to test the causal effect of fetal sex on maternal outcomes.

METHODS

Holstein dairy cows were stratified and randomized using sealed opaque envelopes to be artificially inseminated with either X- or Y-sorted bull semen until 40 cows became pregnant. Monthly body weight measurements were recorded, and an intravenous glucose tolerance test was performed 30 days before the expected calving day. The primary outcome was insulin area under the curve (AUC), and secondary outcomes were clearance rate, half-life, and AUC for glucose, insulin, and non-esterified fatty acid concentrations. An intention-to-treat (ITT) approach using multiple imputation was employed for primary analysis, and an as-treated (AT) approach was used for secondary analysis.

RESULTS

We demonstrated that we could successfully randomize the assignment of fetal sex to dams and test for causal effects of fetal sex on glucoregulatory outcomes using dairy cows as a model. Insulin AUC was not statistically different between groups (ITT p = 0.857, AT p = 0.874), and other outcomes were also not statistically different (p > 0.05).

CONCLUSION

We demonstrated that causal effects of fetal sex on maternal outcomes can be causally tested in dairy cows. Our study did not provide statistical evidence to support an effect of fetal sex on maternal glucose-related outcomes.

Fetal Sexual Dimorphism and Preeclampsia Among Twin Pregnancies

BACKGROUND

In singleton pregnancies, fetal sexual dimorphism has been observed in hypertensive disorders of pregnancy, particularly preeclampsia, a morbid syndrome that increases the risk of adult-onset cardiovascular disease for mothers and their offspring. However, few studies have explored the effect of fetal sex on hypertensive disorders of pregnancy among twin pregnancies.

METHODS

We conducted a retrospective cohort study of 1032 twin pregnancies between 2011 and 2022 using data from a perinatal database that recruits participants from 3 hospitals in Houston, TX. We categorized pregnancies based on fetal sex pairings into female/female, male/male, and female/male. Pregnancies with female/female pairs were used as our reference group. Our primary outcomes included gestational hypertension, preeclampsia, superimposed preeclampsia, and preeclampsia subtyped by gestational age of delivery. A modified Poisson regression model with robust error variance was used to calculate the relative risk and 95% CI for the association between fetal sex pairs and hypertensive disorders of pregnancy.

RESULTS

Adjusted models of female/male pairs were associated with preterm preeclampsia (relative risk, 2.01 [95% CI, 1.15-3.53]) relative to those with female/female pairs. No associations with other hypertensive disorders of pregnancy were observed among pregnancies with male/male pairs compared with those with female/female fetal sex pairs.

CONCLUSIONS

We found some evidence of sexual dimorphism for preterm preeclampsia among female/male twin pairs. Additional research is needed to understand what biological mechanisms could explain these findings.

Development and validation of machine learning-augmented algorithm for insulin sensitivity assessment in the community and primary care settings: a population-based study in China

Objective

Insulin plays a central role in the regulation of energy and glucose homeostasis, and insulin resistance (IR) is widely considered as the "common soil" of a cluster of cardiometabolic disorders. Assessment of insulin sensitivity is very important in preventing and treating IR-related disease. This study aims to develop and validate machine learning (ML)-augmented algorithms for insulin sensitivity assessment in the community and primary care settings.

Methods

We analyzed the data of 9358 participants over 40 years old who participated in the population-based cohort of the Hubei center of the REACTION study (Risk Evaluation of Cancers in Chinese Diabetic Individuals). Three non-ensemble algorithms and four ensemble algorithms were used to develop the models with 70 non-laboratory variables for the community and 87 (70 non-laboratory and 17 laboratory) variables for the primary care settings to screen the classifier of the state-of-the-art. The models with the best performance were further streamlined using top-ranked 5, 8, 10, 13, 15, and 20 features. Performances of these ML models were evaluated using the area under the receiver operating characteristic curve (AUROC), the area under the precision-recall curve (AUPR), and the Brier score. The Shapley additive explanation (SHAP) analysis was employed to evaluate the importance of features and interpret the models.

Results

The LightGBM models developed for the community (AUROC 0.794, AUPR 0.575, Brier score 0.145) and primary care settings (AUROC 0.867, AUPR 0.705, Brier score 0.119) achieved higher performance than the models constructed by the other six algorithms. The streamlined LightGBM models for the community (AUROC 0.791, AUPR 0.563, Brier score 0.146) and primary care settings (AUROC 0.863, AUPR 0.692, Brier score 0.124) using the 20 top-ranked variables also showed excellent performance. SHAP analysis indicated that the top-ranked features included fasting plasma glucose (FPG), waist circumference (WC), body mass index (BMI), triglycerides (TG), gender, waist-to-height ratio (WHtR), the number of daughters born, resting pulse rate (RPR), etc.

Conclusion

The ML models using the LightGBM algorithm are efficient to predict insulin sensitivity in the community and primary care settings accurately and might potentially become an efficient and practical tool for insulin sensitivity assessment in these settings.

The effect of circulating adiponectin levels on incident gestational diabetes mellitus: systematic review and meta‑analysis

BACKGROUND

To quantitatively synthesize evidence from prospective observational studies regarding the mean levels of circulating adiponectin in patients with gestational diabetes mellitus (GDM) and the association between adiponectin levels and GDM risk.

METHODS

PubMed, EMBASE and Web of Science were searched from their inception until November 8th, 2022, for nested case-control studies and cohort studies. Random-effect models were applied to the synthesized effect sizes. The difference in circulating adiponectin levels between the GDM and control groups was measured using the pooled standardized mean difference (SMD) and 95% confidence interval (CI). The relationship between circulating adiponectin levels and GDM risk was examined using the combined odds ratio (OR) and 95% CI. Subgroup analyses were performed according to the study continent, GDM risk in the study population, study design, gestational weeks of circulating adiponectin detection, GDM diagnostic criteria, and study quality. Sensitivity and cumulative analyses were performed to evaluate the stability of the meta-analysis. Publication bias was assessed by funnel plots and Egger's test.

RESULTS

The 28 studies included 13 cohort studies and 15 nested case-control studies, containing 12,256 pregnant women in total. The mean adiponectin level in GDM patients was significantly lower than in controls (SMD = -1.514, 95% CI = -2.400 to -0.628, p = .001, I² = 99%). The risk of GDM was significantly decreased among pregnant women with increasing levels of circulating adiponectin (OR = 0.368, 95% CI = 0.271-0.500, p < .001, I²=83%). There were no significant differences between the subgroups.

CONCLUSIONS

Our findings indicate that increasing circulating adiponectin levels were inversely associated with the risk of GDM. Given the inherent heterogeneity and publication bias of the included studies, further well-designed large-scale prospective cohort or intervention studies are needed to confirm our finding.

Fetal sex and the development of gestational diabetes mellitus in gravidae with multiple gestation pregnancies

INTRODUCTION

There is an increasing incidence of pregnancies with twin gestations. One outcome more likely to occur with multiple gestations is gestational diabetes mellitus. Studies have suggested that in singleton pregnancies, fetal sex may affect insulin resistance. However, the effects of fetal sex in twins and the development of gestational diabetes mellitus are unknown. We hypothesized that rates of gestational diabetes mellitus and degree of insulin resistance might vary in twin gestations based on the fetal sex pairing: male-male, male-female or female-female. We aimed to employ a large population-based database to ascertain any correlations between fetal sex and gestational diabetes mellitus in multifetal gestations.

MATERIAL AND METHODS

A two-hospital, single academic institution database comprised of over 39 000 participants with pregnancy data from August 2011 to January 2022 was employed. All twin deliveries of live-born neonates >24 weeks' gestational age from gravidae without preexisting diabetes or twin-twin transfusion syndrome were included. Entries were then grouped based on the fetal sex of the pairing. The presence or absence of gestational diabetes and type of gestational diabetes - diet-controlled (gestational diabetes mellitus classification A1) vs medication-controlled (gestational diabetes mellitus classification A2) - were identified. Statistical analysis was performed using a generalized linear mixed method, and a P-value ≤0.05 was considered statistically significant.

RESULTS

We identified 1924 twin deliveries that met the inclusion criteria in our database (male-male =652; male-female = 638; female-female = 634). We found no association between fetal sex pairing and the development of gestational diabetes mellitus. There was a significant association between the fetal sex pairing and the type of gestational diabetes mellitus developed, with 32.0% of male-male twins, 33.3% of male-female twins and 58.3% of the female-female twin deliveries associated with medication-controlled gestational diabetes classification A2: male-female vs female-female (P = 0.05) and male-male vs female-female (P = 0.046).

CONCLUSIONS

While gestational diabetes mellitus is of multifactorial origin, we found a significant association between the fetal sex pairing and the treatment needed for gravidae with twins who develop gestational diabetes mellitus. A higher proportion of female-female twins was associated with gestational diabetes classification A2 compared with male-female or male-male deliveries. Further research on the physiology driving this association is warranted.

Fetal sexual dimorphism and preeclampsia among twin pregnancies

Background

In singleton pregnancies, fetal sexual dimorphism has been observed in hypertensive disorders of pregnancy (HDP), particularly preeclampsia, a morbid syndrome that increases risk of adult onset cardiovascular disease for mothers and their offspring. However, few studies have explored the effect of fetal sex on HDP among twin pregnancies.

Methods

We conducted a retrospective cohort study of 1,032 twin pregnancies between 2011 - 2022 using data from a perinatal database that recruits participants from three hospitals in Houston, TX. We categorized pregnancies based on fetal sex pairings into female/female, male/male, and female/male. Pregnancies with a female/female fetal sex were used as our reference group. Our primary outcomes included gestational hypertension, preeclampsia, superimposed preeclampsia, and preeclampsia subtyped by gestational age of delivery. A modified Poisson regression model with robust error variance was used to calculate the relative risk (RR) and 95% confidence interval (CI) for the association between fetal sex pairs and HDP.

Results

Adjusted models of female/male fetal sex pairs were associated with preterm preeclampsia (RR 2.01, 95% CI 1.15-3.53) relative to those with female/female fetuses. No associations with other HDP were observed among pregnancies with male/male fetal sex compared to those with female/female fetal sex pairs.

Conclusions

We found some evidence of sexual dimorphism for preterm preeclampsia among female/male twin pairs. Additional research is needed to understand what biological mechanisms could explain these findings.

Exposure to per- and polyfluoroalkyl substances in early pregnancy, risk of gestational diabetes mellitus, potential pathways, and influencing factors in pregnant women: A nested case-control study

Although previous studies have reported an association between maternal serum perfluoroalkyl substance (PFAS) exposure and gestational diabetes mellitus (GDM) risk, results have been inconsistent. Few studies have focused on the combined effects of emerging and legacy PFASs on glucose homeostasis while humans are always exposed to multiple PFASs simultaneously. Moreover, the potential pathways by which PFAS exposure induces GDM are unclear. A total of 295 GDM cases and 295 controls were enrolled from a prospective cohort of 2700 pregnant women in Shanghai, China. In total, 16 PFASs were determined in maternal spot serum samples in early pregnancy. We used conditional logistic regression, multiple linear regression, and Bayesian kernel machine regression (BKMR) to examine individual and joint effects of PFAS exposure on GDM risk and oral glucose tolerance test outcomes. The mediating effects of maternal serum biochemical parameters, including thyroid and liver function were further assessed. Maternal perfluorooctanoic acid (PFOA) exposure was associated with an increased risk of GDM (odds ratio (OR) = 1.68; 95% confidence interval (95% CI): 1.10, 2.57), consistent with higher concentrations in GDM cases than controls. Based on mediation analysis, an increase in the free triiodothyronine to free thyroxine ratio partially explained the effect of this association. For continuous glycemic outcomes, positive associations were observed between several PFASs and 1-h and 2-h glucose levels. In BKMR, PFAS mixture exposure showed a positive trend with GDM incidence, although the CIs were wide. These associations were more pronounced among women with normal pre-pregnancy body mass index (BMI). Mixed PFAS congeners may affect glucose homeostasis by increasing 1-h glucose levels, with perfluorononanoic acid found to be a main contributor. Exposure to PFASs was associated with increased risk of GDM and disturbance in glucose homeostasis, especially in normal weight women. The PFAS-associated disruption of maternal thyroid function may alter glucose homeostasis.

Fetal sex and the development of gestational diabetes mellitus in polycystic ovarian syndrome gravidae

BACKGROUND

Polycystic ovarian syndrome is characterized by elevated androgens and is a well-known risk factor for the occurrence of gestational diabetes mellitus. Androgens (particularly dehydroepiandrosterone-sulfate) are crucial for the development and characteristics of the male reproductive tract during fetal life, and fetal dehydroepiandrosterone-sulfate enters the placenta where it is metabolized and functions as an estrogen substrate. Given this unique sex-specific relationship with androgens and the association of serum dehydroepiandrosterone-sulfate concentration with insulin resistance, we hypothesized that metabolic comorbidities in pregnancy might differ by fetal sex in gravidae with polycystic ovarian syndrome, notably in those with infertility.

OBJECTIVE

This study aimed to evaluate the data in a large population-based database to explore if fetal sex was significantly associated with gestational diabetes mellitus in gravidae with infertility and polycystic ovarian syndrome after controlling for confounders.

STUDY DESIGN

This study was designed to evaluate the risk for the occurrence and rates of gestational diabetes mellitus among gravidae with infertility and a history of polycystic ovarian syndrome. We used a 2-hospital, single academic institution database comprising more than 30,000 subjects enrolled from September 2011 to June 2021 to identify all gravidae with diagnoses of infertility and polycystic ovarian syndrome at the time of delivery and to compare them with gravidae who lacked these comorbidities. Data on covariates, including but not limited to maternal age, body mass index, fetal sex, race, ethnicity, presence or absence of hypertensive disease, and presence or absence of gestational diabetes were identified. Unadjusted and adjusted odds rations were calculated.

RESULTS

We found a statistically significant association between fetal female sex and the development of gestational diabetes mellitus in gravidae with polycystic ovarian syndrome (odds ratio for female vs male, 2.13; 95% confidence interval, 1.06-4.32; P=.03). After adjusting for potential confounders identified in our univariate analyses, there continued to be a statistically significant association between female fetuses and the development of gestational diabetes mellitus (adjusted odds ratio for female vs male, 2.10; 95% confidence interval, 1.04-4.41; P=.04). In contrast, there was no significant association between fetal sex and the development of gestational diabetes mellitus in our similar analysis of gravidae without infertility and polycystic ovarian syndrome (P=.99).

CONCLUSION

Although the origin of gestational diabetes mellitus is multifactorial, we found that female fetal sex is associated with gestational diabetes mellitus in gravidae with infertility and polycystic ovarian syndrome but not in their comparative controls. Further research on the molecular mechanisms driving the association between female fetuses and the development of gestational diabetes mellitus in the context of maternal polycystic ovarian syndrome is warranted.

Evaluating the Impact of Fetal Sex on Gestational Diabetes Mellitus Following Interaction with Maternal Characteristics

Fetal-sex-specific changes to placental immunity and metabolism occur in response to obesity. Few studies have determined if fetal sex interacts with maternal characteristics to alter risk of gestational diabetes mellitus (GDM). Among 43,727 singleton pregnancies, we examined the association between male fetal sex and GDM using log-binomial logistic regression to calculate relative risks (RR) and 95% confidence intervals (CI). Interactions were examined between fetal sex and maternal characteristics on the risk of GDM by calculating relative excess risk due to interaction. After adjusting for body mass index, race/ethnicity, maternal age, education, and gravidity, male fetal sex was not associated with GDM (RRadj. 0.95, 95% CI 0.93, 1.04). We found a positive interaction between male fetal sex and obesity (p = 0.04). Nonobese women with male fetuses were less likely to develop GDM, but in the presence of obesity, an opposite trend was observed. There was a positive interaction between male fetal sex and GDM on the risk of preterm delivery < 37-weeks gestation (p = 0.0006). In response to underlying maternal obesity, fetal sex may modify the risk of GDM. In addition, male fetal sex may increase the occurrence of preterm birth among women with GDM.

Pentachlorophenol exposure in early pregnancy and gestational diabetes mellitus: A nested case-control study

Pentachlorophenol (PCP) is an endocrine-disrupting chemical that is ubiquitously found in the environment. Few studies have reported PCP exposure in pregnant women and its association with gestational diabetes mellitus (GDM). This nested case-control study aimed to determine the concentration of urinary PCP in early pregnancy and explore the association between PCP exposure and GDM risk. This study included 293 GDM cases and 586 non-GDM controls matched by fetal sex and maternal age from a birth cohort in Wuhan, China. PCP concentrations in spot urine samples collected between 8 and 16 weeks of gestation were measured by ultra-performance liquid chromatography-tandem mass spectrometry. Conditional logistic regression was used to assess the association between PCP exposure and the odds ratio of GDM. The median concentrations of specific gravity-adjusted PCP in controls and cases were 0.70 and 0.80 ng/mL, respectively, with no significant differences (P > 0.05). The multivariate-adjusted odds ratios (ORs) (95% confidence intervals) for GDM across quartiles of urinary PCP were 1 (reference), 1.63 (1.06-2.50), 1.70 (1.11-2.61), and 1.35 (0.87-2.08), respectively, showing a potential "inverted-U" shaped association. In addition, PCP levels and maternal age or fetal sex had significant interactions with GDM risk (both P for interaction < 0.05). Among older women and those carrying female fetuses, the ORs of GDM risk were higher. This study suggests that pregnant women in central China are widely exposed to PCP, and this is the first time to report that PCP exposure may increase the risk of GDM (with potential effect modifications by maternal age and fetal sex). The association observed is in agreement with PCP's "inverted-U" anti-estrogenic effect in vivo; thus, such an effect in humans at environmentally relevant doses should be studied further.

Increased basal insulin sensitivity in late pregnancy in women carrying a male fetus: a cohort study

BACKGROUND

It has been suggested that fetal sex may be able to modify maternal metabolism and physiology during pregnancy. Recently pregnant women carrying a male fetus were reported to be more insulin sensitive than those carrying females, although related evidence is inconsistent.

METHODS

In this study we administered a 75 g oral glucose tolerance test at around week 28 of pregnancy in 813 pregnant women from a contemporary birth cohort (the Cambridge Baby Growth Study), derived surrogate indices of insulin secretion and sensitivity, and related them to the fetal sex.

RESULTS

Carrying a male fetus was associated with lower fasting glucose (difference in mean concentrations ≈ 0.1 mmol/L; β' = 0.063; p = 0.02) and insulin (≈ 1.1 pmol/L; β' = 0.075; p = 0.01) concentrations but not with post-load glucose or insulin concentrations. Male fetal sex was also associated with lower HOMA IR (≈ 1.08 units; β' = 0.071; p = 0.02) and higher QUICKI (≈ 1.06 units; β' = 0.080; p = 0.007) values suggesting increased basal insulin sensitivity. There were no differences in indices of insulin secretion, except for the insulin disposition index which was higher in women carrying a male fetus (≈ 1.15 units; β' = 0.090; p = 0.007). Birth weights were higher in male offspring.

CONCLUSIONS

Women carrying a male fetus were relatively more insulin sensitive in the fasting state and secreted more insulin relative to this degree of insulin sensitivity. These results are consistent with the idea that the fetal sex may be able to modify the maternal glucose-insulin axis.

The impact of fetal sex on risk factors for gestational diabetes and related adverse pregnancy outcomes

AIMS

To investigate whether fetal sex affects the impact of classical GDM risk factors on the diagnosis of gestational diabetes (GDM) as well as on related adverse pregnancy outcomes.

METHODS

This retrospective observational study concerned 206,917 singleton live births born to 170,126 women aged 15-45 over the years 2010-2018 in Tuscany, Italy. GDM was identified by administrative data-sources in 21,613 pregnancies (10.5%) by assessing, through multiple logistic models, whether fetal sex modified the risk of GDM driven by maternal risk factors, and whether it modified the risk of adverse outcomes such as prematurity (birth ≤ 37th gestational week), large for gestational age (LGA), unplanned caesarean sections, or 5-min-Apgar-index ≤ 7 in pregnancies with GDM.

RESULTS

GDM was diagnosed in 21,613 pregnancies (10.5%). Male fetal sex predicted a higher adjusted risk of GDM: OR = 1.05(95% CI: 1.01-1.07); p < 0.0009. In pregnancies with female sex, pre-pregnancy obesity amplified the risk of GDM: OR = 1.09(95% CI: 1.01-1.19); p =  0.04. In pregnancies with GDM, carrying a female fetus increased the risk of LGA associated with pregestational obesity OR = 1.45(95% CI: 1.15-1.81); p = 0.001, and in primiparous pregnancies, it protected mothers from the risk of unplanned caesarean sections OR = 0.80(95%CI: 0.67-0.92); p = 0.001.

CONCLUSIONS

While male fetal sex is associated with rise in the risk of GDM, giving birth to a girl amplifies the excess GDM risk driven by pregestational obesity, thus increasing the risk of LGA in pregnancies with GDM. Additionally, female fetal sex in pregnancies with GDM seems to protect from the risk of unplanned caesarean sections in primiparous pregnancies.

Type 2 Diabetes in Women: Differences and Difficulties

BACKGROUND

Lifestyle modification, along with medication, has improved the quality of life of patients with type 2 diabetes (T2D), but the treatment of diabetes in women still lacks a gender-centric approach.

METHODS

Expert opinions to improve diabetes management in women were collated from the open discussion forum organized by the sixth Jothydev's Professional Education Forum Diabetes Convention, which included global diabetes care experts and the general public. The review is also based on the studies published in electronic databases such as PubMed and Google Scholar that discussed the problems and challenges faced by the Indian diabetes care sector in treating women with diabetes.

RESULTS

The complex interplay of biological, socioeconomic, psychosocial, and physiological factors in women with type 2 diabetes has not been well addressed to date. Biological factors such as neurohumoral pathways, sex hormones, genetic predisposition as well as gender-based environmental and behavioural differences must be considered for modern personalized diabetes treatment. Most importantly, pregnant women with diabetes deserve special attention. This vulnerable phase has a marked impact on the future health of both the mother and the offspring.

CONCLUSION

The review provides an overview of the challenges and issues that exist in the clinical management of diabetes and its complications among women in India. Women-centric clinical approaches should be encouraged for the effective management of diabetes in Indian women.

Environmental contaminants and the disproportionate prevalence of type-2 diabetes mellitus among Indigenous Cree women in James Bay Quebec, Canada

Indigenous populations are disproportionately affected by type 2 diabetes (T2DM) compared to non-Indigenous people. Of importance, the prevalence of T2DM is greater amongst females than males in First Nations communities, in contrast to higher male prevalence reported in non-Indigenous Canadians. Therefore, in this study we extend our previously published work with respect to females, and the potential association between environmental exposures to organochlorine pesticides, such as dichlorodiphenyltrichloroethane (DDT), and dichlorodiphenyldichloroethylene (DDE) to explain the greater prevalence of T2DM among Indigenous females compared to males. Using data from the Multi-Community Environment-and-Health Study, Principal Component Analysis (PCA), examined 9-polychlorinated biphenyl congeners, 7-organic pesticides, and 4-metal/metalloids. Modified Poisson regression with robust error variance estimated adjusted prevalence ratios (PR) and corresponding 95% confidence intervals (95% CI), regressing prevalent T2DM on the newly derived principal components (PC), adjusting for a priori covariates, including parity. We further examined the relationship between high detection concentrations of DDT and tertials of categorized DDE exposures on T2DM among Indigenous Cree women. Among 419 female participants, 23% (n = 95) had physician-diagnosed T2DM. PCA analysis show that DDT and Lead (Pb) loaded highly on the second axis (PC-2), although in opposite directions, indicating the different exposure sources. As previously published, T2DM was significantly associated with PC-2 across adjusted models, however, after further adjusting for parity in this analysis, T2DM was no longer significantly associated with increasing PC-2 scores (PR = 0.88, 95% 0.76, 1.03). Furthermore, we found that the highest detectable levels of DDT, and tertiles of DDE were significantly associated with prevalent T2DM in the fully adjusted model (PR = 1.93, 1.17, 3.19), and (PR = 3.58, 1.10, 11.70), respectively. This cross-sectional analysis suggests organochlorines, specifically, detectable high exposure concentrations of DDT and DDE are associated with prevalent type 2 diabetes, signifying a possible important link between parity and environmental organochlorines pesticides among Indigenous Cree women.

Placental Endocrine Activity: Adaptation and Disruption of Maternal Glucose Metabolism in Pregnancy and the Influence of Fetal Sex

The placenta is an endocrine fetal organ, which secretes a plethora of steroid- and proteo-hormones, metabolic proteins, growth factors, and cytokines in order to adapt maternal physiology to pregnancy. Central to the growth of the fetus is the supply with nutrients, foremost with glucose. Therefore, during pregnancy, maternal insulin resistance arises, which elevates maternal blood glucose levels, and consequently ensures an adequate glucose supply for the developing fetus. At the same time, maternal β-cell mass and function increase to compensate for the higher insulin demand. These adaptations are also regulated by the endocrine function of the placenta. Excessive insulin resistance or the inability to increase insulin production accordingly disrupts physiological modulation of pregnancy mediated glucose metabolism and may cause maternal gestational diabetes (GDM). A growing body of evidence suggests that this adaptation of maternal glucose metabolism differs between pregnancies carrying a girl vs. pregnancies carrying a boy. Moreover, the risk of developing GDM differs depending on the sex of the fetus. Sex differences in placenta derived hormones and bioactive proteins, which adapt and modulate maternal glucose metabolism, are likely to contribute to this sexual dimorphism. This review provides an overview on the adaptation and maladaptation of maternal glucose metabolism by placenta-derived factors, and highlights sex differences in this regulatory network.

Fetal sex and maternal insulin resistance during mid-pregnancy: a retrospective cohort study

Background

Recent studies have suggested that fetal sex influences maternal glucose and insulin metabolism during pregnancy. We examined whether fetal sex is associated with maternal insulin resistance and the β-cell function during mid-pregnancy.

Methods

This retrospective study included singleton pregnant women who underwent a 75-g oral glucose tolerance test (OGTT) at 24–34 weeks of gestation due to positive diabetic screening. In addition to plasma glucose (PG), we measured plasma insulin during the OGTT to obtain surrogate indices associated with insulin resistance (IR), including homeostasis assessment model (HOMA) -IR and insulin sensitivity index (IsOGTT), and β-cell function, including insulinogenic index (II), HOMA-β, and area under the curve of insulin response. We compared these indices between women carrying male fetuses to those carrying female fetuses.

Results

The study population included 617 women (mean age, 32.4 ± 4.9 years) with a mean pre-pregnancy body mass index (BMI) of 22.6±4.5. They underwent the 75g-OGTT at 29.0 ± 2.5 weeks. Two hundred fifty-eight (42%) women were diagnosed with gestational diabetes (GDM). There was no significant difference in maternal age, pre-pregnancy BMI, gestational age at OGTT, PG at OGTT, or the prevalence of GDM between women with a male fetus (n=338) (male group) and those with a female fetus (n=279) (female group). Regarding the indices of IR, IR was significantly higher and insulin sensitivity was lower in the female group than in the male group (HOMA-IR: 7.0 [5-9.6] vs. 6.2 [4.6-8.8], p< 0.05; IsOGTT: 5.86 [4.29-7.83] vs. 6.29 [4.59-8.84], p< 0.01) (median [quartile range]). These differences remained significant after adjustment for maternal age, pre-pregnancy BMI, gestational age and fasting PG at OGTT, and the diagnosis of GDM. In contrast, the β-cell function did not differ between the two groups.

Conclusion

Maternal IR during mid-pregnancy was significantly higher in women carrying a female fetus than in those with a male fetus. The sex of the fetus may affect maternal insulin sensitivity during mid-pregnancy.

Prenatal Hyperglycemia Exposure and Cellular Stress, a Sugar-Coated View of Early Programming of Metabolic Diseases

Worldwide, the number of people with diabetes has quadrupled since 1980 reaching 422 million in 2014 (World Health Organization). This distressing rise in diabetes also affects pregnant women and thus, in regard to early programming of adult diseases, creates a vicious cycle of metabolic dysfunction passed from one generation to another. Metabolic diseases are complex and caused by the interplay between genetic and environmental factors. High-glucose exposure during in utero development, as observed with gestational diabetes mellitus (GDM), is an established risk factor for metabolic diseases. Despite intense efforts to better understand this phenomenon of early memory little is known about the molecular mechanisms associating early exposure to long-term diseases risk. However, evidence promotes glucose associated oxidative stress as one of the molecular mechanisms able to influence susceptibility to metabolic diseases. Thus, we decided here to further explore the relationship between early glucose exposure and cellular stress in the context of early development, and focus on the concept of glycemic memory, its consequences, and sexual dimorphic and epigenetic aspects.

Fetal sex and maternal pregnancy outcomes: a systematic review and meta-analysis

Background

Since the placenta also has a sex, fetal sex–specific differences in the occurrence of placenta-mediated complications could exist.

Objective

To determine the association of fetal sex with multiple maternal pregnancy complications.

Search strategy

Six electronic databases Ovid MEDLINE, EMBASE, Cochrane Central, Web-of-Science, PubMed, and Google Scholar were systematically searched to identify eligible studies. Reference lists of the included studies and contact with experts were also used for identification of studies.

Selection criteria

Observational studies that assessed fetal sex and the presence of maternal pregnancy complications within singleton pregnancies.

Data collection and analyses

Data were extracted by 2 independent reviewers using a predesigned data collection form.

Main results

From 6522 original references, 74 studies were selected, including over 12,5 million women. Male fetal sex was associated with term pre-eclampsia (pooled OR 1.07 [95%CI 1.06 to 1.09]) and gestational diabetes (pooled OR 1.04 [1.02 to 1.07]). All other pregnancy complications (i.e., gestational hypertension, total pre-eclampsia, eclampsia, placental abruption, and post-partum hemorrhage) tended to be associated with male fetal sex, except for preterm pre-eclampsia, which was more associated with female fetal sex. Overall quality of the included studies was good. Between-study heterogeneity was high due to differences in study population and outcome definition.

Conclusion

This meta-analysis suggests that the occurrence of pregnancy complications differ according to fetal sex with a higher cardiovascular and metabolic load for the mother in the presence of a male fetus.

Funding

None.

Limited Impact of Fetal Sex and Maternal Body Mass Index on Fetal and Maternal Insulin Resistance and Lipid Metabolism: Findings from the PEARs Study

The intrauterine environment can have a significant impact on fetal and maternal well-being, both during pregnancy and in later life. We aimed to identify how fetal sex and maternal body mass index (BMI) influence insulin resistance and metabolic function during pregnancy with maternal BMI > 25 kg/m². This secondary analysis assessed data from the PEARS-randomized controlled trial that recruited pregnant women with body mass indexes 25-39.9 kg/m². Longitudinal measurements of maternal and fetal insulin resistance and metabolic function were recorded throughout pregnancy. Regression models tested the effects of fetal sex and maternal BMI on markers of metabolic function and insulin regulation. A total of 484 women and their newborns (252 (52%) males vs. 232 (48%) females) were included in the analysis. A total of 333 (69%) women were overweight and 151 (31%) were obese. Male newborns were heavier and larger than females, and had a higher rate of instrumental delivery. Males had a lower LDL, but no other markers of insulin resistance or metabolic function were affected by fetal sex. Women with obesity had elevated markers of insulin resistance and metabolic dysfunction compared with women that were overweight, but maternal BMI did not impact these variables in the fetus. Fetal sex did not impact maternal and fetal metabolic parameters in women with BMI > 25 kg/m². However, a higher BMI caused increasingly deranged maternal blood lipid concentrations and markers of insulin resistance as pregnancy progressed. Lipid monitoring and interventions to reduce lipids during pregnancy therefore require further evaluation.

Exploring Fetal Sex Dimorphism in the Risk Factors of Gestational Diabetes Mellitus-A Prospective Cohort Study

Gestational diabetes mellitus (GDM) is a common pregnancy complication. Its etiology remains incompletely understood. Studies in recent years suggest that fetal sex may affect maternal metabolic milieu during pregnancy. We sought to assess whether there is fetal sex dimorphism in the risk factors of GDM. In a prospective pregnancy cohort in Shanghai, China, we studied 2,435 singleton pregnant women without pre-existing diabetes. GDM was diagnosed according to the International Association of Diabetes and Pregnancy Study Groups (IADPSG)' criteria. Log-binomial models were applied to obtain the adjusted relative risk (aRR). A total of 380 (15.6%) women developed GDM. Family history of diabetes was associated with an increased risk of GDM in women bearing a female fetus [aRR 1.74 (1.27-2.40), p < 0.001], but not in women bearing a male fetus (p = 0.68) (test for interaction, p = 0.03). Alcohol drinking was associated with an increased risk of GDM in women bearing a male fetus only (p = 0.023), although the test for interaction did not reach statistical significance (p = 0.055). In conclusion, family history of diabetes was associated with an increased risk of GDM in women bearing a female fetus only in this Chinese pregnancy cohort. There may be a need to consider fetal sex dimorphism in evaluating the risk factors of GDM.

Female babies and risk-aversion: Causal evidence from hospital wards

Using ultrasound scan data from paediatric hospitals, and the exogenous 'shock' of learning the gender of an unborn baby, the paper documents the first causal evidence that offspring gender affects adult risk-aversion. On a standard Holt-Laury criterion, parents of daughters, whether unborn or recently born, become almost twice as risk-averse as parents of sons. The study demonstrates this in longitudinal and cross-sectional data, for fathers and mothers, for babies in the womb and new-born children, and in a West European nation and East European nation. These findings may eventually aid our understanding of risky health behaviors and gender inequalities.

Fetal sex influences maternal fasting plasma glucose levels and basal β-cell function in pregnant women with normal glucose tolerance

AIMS

Fetal sex has recently emerged as a new factor that is related to maternal glucose homeostasis during pregnancy. The present study aimed to investigate the effect of fetal sex on maternal glucose metabolism in women with normal glucose tolerance (NGT) during pregnancy in the Chinese population.

METHODS

A total of 877 pregnant women with NGT were recruited at 24-28 weeks of gestation and underwent a 75-g oral glucose tolerance test (OGTT). Pregnant women were divided into two groups according to fetal sex. Physical examinations and laboratory tests were performed. Pancreatic β-cell function and insulin sensitivity were evaluated using OGTT-derived indices.

RESULTS

Compared with women bearing female fetuses, women who delivered male fetuses had higher fasting plasma glucose (FPG) concentrations [4.5 (4.2-4.8) vs. 4.4 (4.2-4.7) mmol/L, P < 0.05], but lower HOMA-β [161.9 (118.2-238.8) vs. 181.0 (131.7-260.9), P < 0.05] and Stumvoll first phase of insulin secretion [1230.2 (1077.9-1433.7) vs. 1290.9 (1134.0-1493.2), P < 0.05]. Multiple linear regression analysis indicated that the sex of the fetus was independently associated with maternal FPG and HOMA-β. Further binary logistic regression analyses revealed that the presence of a male fetus was significantly associated with elevated FPG [odds ratio (OR) 1.50; 95% confidence interval (CI) 1.12-2.00; P = 0.006] and lower HOMA-β (OR 0.70; 95% CI 0.52-0.94; P = 0.018) even after adjustment for potential confounders.

CONCLUSIONS

This study provided evidence that maternal glucose metabolism could be affected by fetal sex even in NGT pregnant women. Our results suggest that the presence of male fetuses was independently associated with maternal elevated FPG and lower basal β-cell function.

Adipokines and Insulin Resistance According to Characteristics of Pregnant Women with Gestational Diabetes Mellitus

BACKGROUND

The aim of this study was to evaluate adipokines concentration and insulin resistance according to maternal age or obesity at pregnancy and weight change at diagnosed gestational diabetes mellitus (GDM) in pregnant women with GDM.

METHODS

This study included 57 pregnant women who were diagnosed with GDM at 24 to 28 weeks of gestation. The subjects were classified into two or three groups according to pre-pregnancy body mass index (BMI, <25 kg/m² vs. ≥25 kg/m²), maternal age at pregnancy (<35 years old vs. ≥35 years old), and weight change during pregnancy at screening for GDM (weight change below, within, and in excess of the recommended range). They were respectively compared in each group.

RESULTS

Leptin, homeostasis model assessment of insulin resistance (HOMA-IR), and HOMA2-%B were increased in the group with pre-pregnancy BMI ≥25 kg/m². Leptin and HOMA-IR were positively correlated with BMI both before pregnancy and at screening for GDM. There were no significant correlations between HOMA-IR and adipokines. HOMA-IR showed positive correlation with HOMA2-%B and negative correlation with HOMA2-%S.

CONCLUSION

Leptin and HOMA-IR at diagnosed GDM were increased in the GDM patients with obesity before pregnancy. They were positively correlated with BMI both before pregnancy and at screening for GDM. The effect of maternal age at pregnancy and weight change during pregnancy at GDM screening on adipokines and insulin resistance might be less pronounced than the effect of maternal obesity.

High Prevalence of Gestational Diabetes Mellitus in Beijing: Effect of Maternal Birth Weight and Other Risk Factors

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with both short- and long-term adverse health consequences for both the mother and her offspring. The aim was to study the prevalence and risk factors for GDM in Beijing.

METHODS

The study population consisted of 15,194 pregnant women attending prenatal care in 15 hospitals in Beijing, who delivered between June 20, 2013, and November 30, 2013, after 28 weeks of gestation. The participants were selected by cluster sampling from the 15 hospitals identified through random systematic sampling based on the number of deliveries in 2012. A questionnaire was designed to collect information.

RESULTS

A total of 2987 (19.7%) women were diagnosed with GDM and 208 (1.4%) had diabetes in pregnancy (DIP). Age (OR: 1.053, 95% CI: 1.033-1.074, P < 0.01), family history of diabetes mellitus (OR: 1.481, 95% CI: 1.254-1.748, P < 0.01), prepregnancy body mass index (BMI) (OR: 1.481, 95% CI: 1.254-1.748, P < 0.01), BMI gain before 24 weeks (OR: 1.126, 95% CI: 1.075-1.800, P < 0.01), maternal birth weight (P < 0.01), and fasting plasma glucose at the first prenatal visit (P < 0.01) were identified as risk factors for GDM. In women with birth weight <3000 g, GDM rate was significantly higher.

CONCLUSIONS

One out of every five pregnant women in Beijing either had GDM or DIP and this constitutes a huge health burden for health services. Prepregnancy BMI and weight gain before 24th week are important modifiable risk factors for GDM. Ensuring birth weight above 3000 g may help reduce risk for future GDM among female offsprings.

Effect of Fetal Sex on Maternal and Obstetric Outcomes

Fetal sex plays an important role in modifying the course and complications related to pregnancy and may also have an impact on maternal health and well-being both during and after pregnancy. The goal of this article is to review and summarize the findings from published research on physiologic and pathologic changes that may be affected by fetal sex and the effect of these changes on the maternal and obstetrical outcomes. This will help create awareness that fetal sex is not just a random chance event but an interactive process between the mother, the placenta, and the fetus. The reported effects of male sex on the course of pregnancy and delivery include higher incidence of preterm labor in singletons and twins, failure of progression in labor, true umbilical cord knots, cord prolapse, nuchal cord, higher cesarean section rate, higher heart rate variability with increased frequency, and duration of decelerations without acidemia and increased risk of gestational diabetes mellitus through the poor beta cells function. Similarly, female fetal sex has been reported to modify pregnancy and delivery outcomes including altered fetal cardiac hemodynamics, increased hypertensive diseases of pregnancy, higher vulnerability of developing type 2 DM after pregnancy possibly because of influences on increased maternal insulin resistance. Placental function is also influenced by fetal sex. Vitamin D metabolism in the placenta varies by fetal sex; and the placenta of a female fetus is more responsive to the relaxing action of magnesium sulfate. Male and female feto-placental units also vary in their responses to environmental toxin exposure. The association of fetal sex with stillbirths is controversial with many studies reporting higher risk of stillbirth in male fetuses; although some smaller and limited studies have reported more stillbirths with female fetus pregnancies. Maternal status such as BMI may in turn also affect the fetus and the placenta in a sex-specific manner. There is probably a sex-specific maternal-placental-fetal interaction that has significant biological implications of which the mechanisms may be genetic, epigenetic, or hormonal. Determination of fetal sex may therefore be an important consideration in management of pregnancy and childbirth.

The sex of the foetus affects maternal blood glucose concentrations in overweight and obese pregnant women

There is increasing evidence that the sex of the foetus may alter the maternal metabolic milieu during pregnancy. Following a randomized controlled trial of exercise in overweight and obese pregnant women, we assessed whether the sex of the foetus was associated with changes in maternal metabolism. Data were analysed on 74 randomized participants who completed the trial, including 38 mothers carrying males and 36 mothers carrying females. At 19 weeks of gestation, mothers carrying boys had higher blood glucose concentrations than those carrying girls (5.4 vs 4.9 mmol/l; p = .046). At 36 weeks of gestation, differences were more marked, with blood glucose concentrations 15% higher in mothers carrying females (5.7 vs 5.0 mmol/l; p = .004). In addition, mothers carrying girls had higher concentrations of hs-CRP across pregnancy (5.0 vs 3.6 mg/l; p = .029). Our findings provide further evidence that the sex of the foetus appears to influence maternal metabolism.

Sex-Specific Associations of Maternal Gestational Glycemia with Hormones in Umbilical Cord Blood at Delivery

Background Few studies have examined sex-specific associations of maternal gestational glycemia with cord blood hormones, which might predict later health. Methods In 976 women without pre-existing diabetes in the Project Viva cohort, we used linear regression to examine associations of maternal gestational glycemia with cord hormone concentrations, adjusted for maternal characteristics and stratified by infant sex. Results A total of 6.1% of women had gestational diabetes mellitus (GDM), 8.8% isolated hyperglycemia, 3.2% gestational impaired glucose tolerance, and 81.9% were normoglycemic. In boys, compared with infants of normoglycemic mothers, infants of GDM mothers had higher cord levels of IGF-2 (β 35.55 ng/mL; 95% CI: 2.60, 68.50), IGFBP-3 (111.2 ng/mL; 5.53, 216.8), insulin (4.66 uU/mL; 2.38, 6.95), C-peptide (0.46 ng/mL; 0.25, 0.67), and leptin (3.51 ng/mL; 1.37, 5.64), but lower IGF-1 (-6.71 ng/mL; -12.7, - 0.76, adjusted for IGFBP-3). In girls, GDM offspring had higher cord blood levels of IGF-1 adjusted for IGFBP-3 (12.45 ng/mL; 4.85, 20.04). Boys, but not girls, of mothers with abnormal glucose tolerance but not GDM also had higher levels of some hormones. Conclusion GDM was associated with growth factors and adipokines in cord blood from boys, but only IGF-1 in girls. These findings suggest sex differences in responses to fetal overnutrition.

Sexual Dimorphism in Adverse Pregnancy Outcomes - A Retrospective Australian Population Study 1981-2011

OBJECTIVES

Sexual inequality starts in utero. The contribution of biological sex to the developmental origins of health and disease is increasingly recognized. The aim of this study was to assess and interpret sexual dimorphisms for three major adverse pregnancy outcomes which affect the health of the neonate, child and potentially adult.

METHODS

Retrospective population-based study of 574,358 South Australian singleton live births during 1981-2011. The incidence of three major adverse pregnancy outcomes [preterm birth (PTB), pregnancy induced hypertensive disorders (PIHD) and gestational diabetes mellitus (GDM)] in relation to fetal sex was compared according to traditional and fetus-at-risk (FAR) approaches.

RESULTS

The traditional approach showed male predominance for PTB [20-24 weeks: Relative Risk (RR) M/F 1.351, 95%-CI 1.274-1.445], spontaneous PTB [25-29 weeks: RR M/F 1.118, 95%-CI 1.044-1.197%], GDM [RR M/F 1.042, 95%-CI 1.011-1.074], overall PIHD [RR M/F 1.053, 95%-CI 1.034-1.072] and PIHD with term birth [RR M/F 1.074, 95%-CI 1.044-1.105]. The FAR approach showed that males were at increased risk for PTB [20-24 weeks: RR M/F 1.273, 95%-CI 1.087-1.490], for spontaneous PTB [25-29 weeks: RR M/F 1.269, 95%-CI 1.143-1.410] and PIHD with term birth [RR M/F 1.074, 95%-CI 1.044-1.105%]. The traditional approach demonstrated female predominance for iatrogenic PTB [25-29 weeks: RR M/F 0.857, 95%-CI 0.780-0.941] and PIHD associated with PTB [25-29 weeks: RR M/F 0.686, 95%-CI 0.581-0.811]. The FAR approach showed that females were at increased risk for PIHD with PTB [25-29 weeks: RR M/F 0.779, 95%-CI 0.648-0.937].

CONCLUSIONS

This study confirms the presence of sexual dimorphisms and presents a coherent framework based on two analytical approaches to assess and interpret the sexual dimorphisms for major adverse pregnancy outcomes. The mechanisms by which these occur remain elusive, but sex differences in placental gene expression and function are likely to play a key role. Further research on sex differences in placental function and maternal adaptation to pregnancy is required to delineate the causal molecular mechanisms in sex-specific pregnancy outcome. Identifying these mechanisms may inform fetal sex specific tailored antenatal and neonatal care.

Sex of the baby and future maternal risk of Type 2 diabetes in women who had gestational diabetes

AIMS

Women who develop gestational diabetes mellitus have a chronic defect in the secretion of insulin by the pancreatic β cells that underlies both their diagnostic hyperglycaemia in pregnancy and their elevated lifetime risk of developing Type 2 diabetes in the future. It has recently emerged that carrying a male fetus is associated with poorer maternal β-cell function and an increased risk of gestational diabetes, whereas the development of gestational diabetes when carrying a girl (as compared with a boy) predicts a comparatively higher risk of early progression to Type 2 diabetes before any subsequent pregnancy. In this context, we sought to determine the impact of fetal sex on the long-term risk of Type 2 diabetes in women with gestational diabetes.

METHODS

Using population-based administrative databases, we identified all women in Ontario, Canada, with a singleton live-birth first pregnancy complicated by gestational diabetes between April 2000 and March 2010 (n = 23 363). We compared the risk of subsequent Type 2 diabetes after pregnancy in those who carried a girl (n = 11 229) vs. those who carried a boy (n = 12 134).

RESULTS

Over median 5.5 years follow-up, 5483 women (23.5%) were diagnosed with diabetes. Compared with those who carried a boy, women who had a girl had an elevated risk of subsequently developing diabetes (adjusted hazard ratio = 1.06, 95% CI 1.01-1.12).

CONCLUSIONS

Among women with gestational diabetes, those who are carrying a girl have a slightly higher overall future risk of Type 2 diabetes.

Sex of the baby and risk of gestational diabetes mellitus in the mother: a systematic review and meta-analysis

AIMS/HYPOTHESIS

It has recently emerged that carrying a male fetus may be associated with poorer maternal beta cell function and an increased risk of gestational diabetes mellitus (GDM). Recognising that the overall impact of fetal sex on maternal glucose metabolism is likely to be subtle, we sought to perform a systematic review and meta-analysis of observational studies to obtain a robust estimate of the incremental maternal risk of GDM associated with the sex of the baby.

METHODS

We searched PubMed and EMBASE to identify observational studies published between 1 January 1950 and 4 April 2015 that reported data on fetal sex and the prevalence of GDM. Two independent reviewers extracted the data and pooled estimates of the RR were calculated by a random-effects model. We considered male fetus as the exposure and prevalence of GDM as the outcome of interest.

RESULTS

We identified 320 studies through electronic searches and nine studies through manual searches. Twenty studies met the inclusion criteria, yielding data on 2,402,643 women. Pooled analysis of these studies demonstrated an increased risk of GDM in women carrying a male fetus compared with women carrying a female fetus (RR 1.04; 95% CI 1.02, 1.06). This result was confirmed in a sensitivity analysis including only studies that applied a stringent definition of GDM (RR 1.03; 95% CI 1.01, 1.06) (I(2) = 0%, p = 0.66).

CONCLUSIONS/INTERPRETATION

Pregnant women carrying a boy have a 4% higher relative risk of GDM than those carrying a girl. The fetus thus may have previously unsuspected effects on maternal glucose metabolism in pregnancy.

The Effects of Fetal Gender on Maternal and Fetal Insulin Resistance

OBJECTIVE

Gender plays a role in the development of a number of cardiovascular and metabolic diseases and it has been suggested that females may be more insulin resistant in utero. We sought to assess the relationship between infant gender and insulin resistance in a large pregnancy cohort.

STUDY DESIGN

This is a secondary analysis of a cohort from the ROLO randomized control trial of low GI diet in pregnancy. Serum insulin, glucose and leptin were measured in early pregnancy and at 28 weeks. At delivery cord blood C-peptide and leptin were measured. A comparison of maternal factors, fetal biometry, insulin resistance and leptin was made between male and female offspring. A multivariate regression model was built to account for the possible effects of maternal BMI, birthweight and original study group assignment on findings.

RESULTS

A total of 582 women were included in this secondary analysis, of whom 304 (52.2%) gave birth to male and 278 (47.8%) gave birth to female infants. Compared to male infants at birth, female infants were significantly lighter, (3945 ± 436 vs. 4081± 549g, p<0.001), shorter in length (52.36 ± 2.3 vs. 53.05 ± 2.4cm, p<0.001) and with smaller head circumferences (35.36 ± 1.5 vs. 36.10 ± 1.1cm, p<0.001) than males. On multiple regression analysis, women pregnant with female fetuses were less insulin resistant in early pregnancy, i.e. had lower HOMA indices (B = -0.19, p = 0.01). Additionally female fetuses had higher concentrations of both cord blood leptin and C-peptide at birth when compared to male offspring (B = 0.38, p<0.001 and B = 0.31, p = 0.03 respectively).

CONCLUSION

These findings suggest gender is a risk factor for insulin resistance in-utero. Additionally, carrying a female fetus decreases the risk of insulin resistance in the mother, from as early as the first trimester.