Systemic endocrinopathies (thyroid conditions and diabetes): impact on postnatal life of the offspring

Association between maternal multimorbidity and neurodevelopment of offspring: a prospective birth cohort study from the Japan Environment and Children's Study

OBJECTIVES

To investigate the association between multimorbidity during pregnancy and neurodevelopmental delay in offspring using data from a Japanese nationwide birth cohort study.

DESIGN

This study was a prospective birth cohort study.

SETTING

This study population included 104 059 fetal records who participated in The Japan Environment and Children's Study from 2011 to 2014.

PARTICIPANTS

Pregnant women whose children had undergone developmental testing were included in this analysis.

PRIMARY AND SECONDARY OUTCOME MEASURES

Neurodevelopment of offspring was assessed using the Japanese version of the Ages and Stages Questionnaire, third edition, comprising five developmental domains. The number of comorbidities among the pregnant women was categorised as zero, single disease or multimorbidity (two or more diseases). Maternal chronic conditions included in multimorbidity were defined as conditions with high prevalence among women of reproductive age. A multivariate logistic regression analysis was conducted to examine the association between multimorbidity in pregnant women and offspring development.

RESULTS

Pregnant women with multimorbidity, single disease and no disease accounted for 3.6%, 30.6% and 65.8%, respectively. The ORs for neurodevelopmental impairment during the follow-up period were similar for infants of mothers with no disease comorbidity and those with a single disease comorbidity. However, the ORs for neurodevelopmental impairment were significantly higher for children born to mothers with multimorbidity compared with those born to healthy mothers.

CONCLUSION

An association was observed between the number of comorbidities in pregnant women and developmental delay in offspring. Multimorbidity in pregnant women may be associated with neurodevelopmental delay in their offspring. Further research is required in this regard in many other regions of the world.

Maternal hypothyroidism and subsequent metabolic outcomes in children: a systematic review and meta-analysis

INTRODUCTION

As the fetus relies on maternal thyroid hormones in early pregnancy, maternal hypothyroidism plays an important role in fetal development. However, the association between maternal hypothyroidism and metabolic disease in offspring is unclear.

OBJECTIVE

To examine the association between maternal hypothyroidism in pregnancy and metabolic outcomes (obesity, hypertension, type 2 diabetes mellitus, and dyslipidemia) in children < 18 years.

METHODS

We systematically searched 5 databases from inception to May 2023. Eligible studies included cohort, case-control, and randomized controlled trials involving children born to mothers with or without hypothyroidism in pregnancy. Data were pooled across studies using random-effects models for outcomes reported in at least three studies. Quality assessment was performed using the ROBINS-E tool for observational studies and the Cochrane Risk of Bias tool for trials.

RESULTS

The search identified 3221 articles, of which 7 studies were included (1 trial, 6 observational). All studies were conducted outside of North America and ranged in size from 250 to > 1 million children. The follow-up time ranged from 6 to 20 years. Included studies support an increased risk of hypertension and glucose dysregulation in offspring exposed to maternal hypothyroidism (hypertension: OR 1.08, 95% CI 0.75, 1.57 and HR 1.81, 95% CI 1.21, 2.69; diabetes: RR 2.7, 95% CI 0.7, 10). In the pooled analysis, maternal hypothyroidism was not associated with obesity in offspring (OR 1.04, 95% CI 0.64, 1.70).

CONCLUSION

This study found inconsistent evidence on the association between maternal hypothyroidism in pregnancy and metabolic outcomes in offspring, though associations with hypertension and glucose dysregulation are possible.

Positive Association between Preserved C-Peptide and Cognitive Function in Pregnant Women with Type-1 Diabetes

This study focused on the cognitive function of women with type 1 diabetes in pregnancy. We investigated risk factors for a low cognitive score such as age, duration of Diabetes, BMI, subclinical hypothyroidism, cardiovascular autonomic neuropathy, the impact of hypo-/hyperglycemia, and C-peptide preservation. Material and methods. Seventy-eight pregnant women with type 1 diabetes (age 31.1 ± 5.4 years, diabetes duration 14.3 ± 8.9 years) were included in the study. Cognitive function was assessed in different domains, such as reasoning, memory, attention, coordination, and perception. Results. The cognitive test values ≥400 were considered high scores, and values <400 were considered low. Relative risks for low scores for general cognitive function were associated with increased BMI > 25 kg/m2 2.208 (95% CI 1.116−4.370), HbA1c > 6.5% RR 0.774 (95% CI 0.366−1.638), subclinical hypothyroidism RR 3.111 (95% CI 1.140−8.491), and impaired cardiovascular autonomic neuropathy RR 2.250 (95% CI 1.000−5.062). Pregnant women with a lower score for general cognitive function had higher BMI and higher leptin levels. Preserved C-peptide reduces the risk for cognitive impairment (RR 0.297 (95% CI 0.097−0.912)) in pregnant women with type 1 diabetes Conclusion. BMI > 25 kg/m2, subclinical hypothyroidism, and cardiovascular autonomic neuropathy are associated with increased risk, and postprandial C-peptide preservation with reduced risk for cognitive impairment in pregnant women with type 1 diabetes.

Impact of caesarean delivery on children's autism-like behaviours: the mediation of exclusive breastfeeding

Background

The rate of autism spectrum disorder (ASD) has been rising worldwide, and therefore it is important to identify potential causes of ASD to facilitate early prevention. This study examined the role of breastfeeding and the association between caesarean delivery (CD) and children’s autism spectrum disorder.

Methods

The data were from the Ma’anshan birth cohort (MABC) in China, that was set up between May 2013 and September 2014. Women within 14 gestational weeks were recruited. The delivery mode was extracted from medical notes and infant feeding was obtained from questionnaire surveys. Autism-like behaviour was assessed using the Checklist for Autism in Toddlers (CHAT-23) when children were 18 months old, and 3 years of age. At 5 years of age, autism-like behaviour was assessed using the Clancy Autism Behavior Scale behavior. Structural equation models tested the mediation effects of breastfeeding between CD and children’s autism spectrum disorder.

Results

In all, 1520 (48.89%) women gave birth via CD, and 406 (13.86%) children were identified with autism-like behaviours at 18 months. Compared with women giving birth via vaginal delivery, those giving birth via CD were more likely to experience a higher proportion of delayed initiation of breastfeeding (p < 0.01), and delayed onset of lactogenesis (p < 0.01). CD was associated with a lower proportion of exclusive breastfeeding at 4 months after delivery (p = 0.02). Autism-like behaviour was less likely amongst infants with exclusively breastfeeding at 4 months than amongst those not exclusively breastfeeding at 4 months (p < 0.01). SEM indicated that women who gave birth by CD were more likely to stop exclusive breastfeeding in the first 4 months (standard estimations = − 0.04, p = 0.02), and those children who were not exclusively breastfed at 4 months were more likely to have autism-like behaviours (standard estimations = − 0.05, p < 0.01). The associations persisted at 3 years, but not at 5 years.

Conclusions

Exclusive breastfeeding at 4 months of age mediated the association between caesarean delivery and children’s autism-like behaviours.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13006-022-00493-6.

Maternal Hypothyroidism in Rats Reduces Placental Lactogen, Lowers Insulin Levels, and Causes Glucose Intolerance

Hypothyroidism increases the incidence of gestational diabetes mellitus (GDM) but the mechanisms responsible are unknown. This study aimed to assess the pathophysiological mechanisms by which hypothyroidism leads to glucose intolerance in pregnancy. Hypothyroidism was induced in female Sprague-Dawley rats by adding methimazole (MMI) to drinking water at moderate (MOD, MMI at 0.005% w/v) and severe (SEV, MMI at 0.02% w/v) doses from 1 week before pregnancy and throughout gestation. A nonpregnant cohort received the same dose for the same duration but were not mated. On gestational day 16 (GD16), or nonpregnant day 16 (NP16), animals were subjected to an intraperitoneal glucose tolerance test. Tissues and blood samples were collected 4 days later. Hypothyroidism induced a diabetic-like phenotype by GD16 in pregnant females only. Pregnant MOD and SEV females had reduced fasting plasma insulin, less insulin following a glucose load, and altered expression of genes involved in insulin signaling within skeletal muscle and adipose tissue. Hypothyroidism reduced rat placental lactogen concentrations, which was accompanied by reduced percentage β-cell cross-sectional area (CSA) relative to total pancreas CSA, and a reduced number of large β-cell clusters in the SEV hypothyroid group. Plasma triglycerides and free fatty acids were reduced by hypothyroidism in pregnant rats, as was the expression of genes that regulate lipid homeostasis. Hypothyroidism in pregnant rats results in a diabetic-like phenotype that is likely mediated by impaired β-cell expansion in pregnancy. This pregnancy-specific phenomenon is likely due to reduced placental lactogen secretion.

Gestational Diabetes Mellitus and Developmental Programming

During normal pregnancy, increased insulin resistance acts as an adaptation to enhance materno-foetal nutrient transfer and meet the nutritional needs of the developing foetus, particularly in relation to glucose requirements. However, about 1 in 6 pregnancies worldwide is affected by the inability of the mother's metabolism to maintain normoglycaemia, with the combination of insulin resistance and insufficient insulin secretion resulting in gestational diabetes mellitus (GDM). A growing body of epidemiologic work demonstrates long-term implications for adverse offspring health resulting from exposure to GDM in utero. The effect of GDM on offspring obesity and cardiometabolic health may be partly influenced by maternal obesity; this suggests that improving glucose and weight control during early pregnancy, or better still before conception, has the potential to lessen the risk to the offspring. The consequences of GDM for microbiome modification in the offspring and the impact upon offspring immune dysregulation are actively developing research areas. Some studies have suggested that GDM impacts offspring neurodevelopmental and cognitive outcomes; confirmatory studies will need to separate the effect of GDM exposure from the complex interplay of social and environmental factors. Animal and human studies have demonstrated the role of epigenetic modifications in underpinning the predisposition to adverse health in offspring exposed to suboptimal hyperglycaemic in utero environment. To date, several epigenome-wide association studies in human have extended our knowledge on linking maternal diabetes-related DNA methylation marks with childhood adiposity-related outcomes. Identification of such epigenetic marks can help guide future research to develop candidate diagnostic biomarkers and preventive or therapeutic strategies. Longer-term interventions and longitudinal studies will be needed to better understand the causality, underlying mechanisms, or impact of GDM treatments to optimize the health of future generations.

Digit ratio, a proposed marker of the prenatal hormone environment, is not associated with prenatal sex steroids, anogenital distance, or gender-typed play behavior in preschool age children

Prenatal hormones have been proposed as key factors impacting child development as well as long-term health and disease. Digit ratio (the ratio of the lengths of the second to fourth digits; 2D:4D) has been proposed as a sexually dimorphic, noninvasive marker of prenatal androgen exposure that can be reliably measured in children and adults. To date, few longitudinal pregnancy cohort studies have examined childhood digit ratio in relation to other relevant measures including prenatal hormones and androgen-sensitive outcomes. To augment the current literature on this topic, we measured right-hand digit ratio in 4-year-old children participating in The Infant Development and the Environment Study, a multicenter longitudinal cohort study that has been following mother-child dyads since the first trimester of pregnancy (n = 321). We assessed sex differences in digit ratio and fit multivariable linear regression models to examine digit ratio in relation to: (1) child sex; (2) maternal sex steroid hormone concentrations in early pregnancy; (3) newborn anogenital distance, another proposed measure of sensitivity to prenatal androgens; and (4) gender-typical play behavior as measured by the Preschool Activities Inventory (PSAI) at age 4. We observed no sex difference in digit ratio; the mean 2D:4D was 0.97 ± 0.05 mm in both sexes. Furthermore, digit ratio was not associated with maternal sex steroid concentrations in early pregnancy, anogenital distance in either sex, or PSAI scores in either sex in covariate-adjusted models. In conclusion, we observed no evidence that early childhood digit ratio was associated with child sex or hormone-sensitive measures in this cohort.