Alterations in the maternal environment may impact on the fetal development. The objective of this study was to investigate the gastrointestinal consequences of maternal hypothyroidism for the male offspring from Wistar rats. The pregnant rats were divided into three groups: control (C – received water), experimental 1 [E1 – received methimazole (MMI) solution] during gestation and lactation, and experimental 2 (E2 – received MMI solution) during gestation. Maternal parameters evaluated: free T3 and T4, bodyweight variation, and water/food intake. Offspring parameters evaluated: litter size, number of male/female, free T3 and T4, stomach area, gastric ulcer susceptibility, small intestine length and weight, small intestine and distal colon motility, the stomach and intestinal weight–body weight ratio (SW/BW–IW/BW), and the accumulation of intestinal fluid. Maternal T3 and T4 from E1 were decreased when compared to the other groups. There were no differences for maternal water/food intake and weight gain, litter size, and number of males and females. Regarding to offspring, free T3, SW/BW, IW/BW, and intestinal fluid accumulation were not different between the groups, but T4 was decreased in E1. However, 30-day-old pups from E1 and E2 were smaller with lower stomach and small intestine. Even more, E1 presented a lower ulcer index when compared to the C, while E2 had a higher distal colon transit. It can be concluded that maternal hypothyroidism impaired the total body development, as well as gastric and intestinal development, besides interfering with the susceptibility to the ulcer and intestinal transit of male offspring from Wistar rats.

Objectives: This study tested whether mothers with maternal hypothyroidism have increased odds of CHD in their offspring, and examined the relationship between CHD, maternal thyroid function, and nausea and vomiting in pregnancy. Background: Maternal hypothyroidism increases the risk for foetal demise and prematurity and can have a negative impact on neurodevelopment. Prior studies have postulated a relationship between maternal thyroid function, CHD, and maternal nausea and vomiting in pregnancy. Methods: A cross-sectional case–control study was conducted over a 17-month period to obtain a history of maternal thyroid status and nausea and vomiting in pregnancy. Paediatric echocardiograms were evaluated for CHD by a blinded paediatric cardiologist. Logistic regression analysis was performed to examine the association between CHD and maternal hypothyroidism. Results: Of the 998 maternal–child pairs, 10% (98/998) of the mothers reported a history of prenatal hypothyroidism. The overall prevalence of CHD in the study sample was 63% (630/998). Mothers with a history of hypothyroidism were significantly more likely to have offspring with CHD compared with mothers without a history of hypothyroidism (72 versus 62%; p=0.04). The adjusted odds ratio (95% confidence interval) of CHD in offspring associated with reported maternal hypothyroidism was 1.68 (1.02–2.78). Conclusion: This study suggests that maternal hypothyroidism is a risk factor for the development of CHD. Further prospective investigations are necessary to confirm this association and delineate pathogenic mechanisms.

Memory deficits and hippocampal abnormalities have been described in individuals with thyroid hormone (TH) insufficiencies; however, no study has yet examined their autobiographical memory (AM) abilities, which are known to be compromised by hippocampal damage. Investigations in adults have shown that AM consists of both episodic and semantic components and that the hippocampus is preferentially involved in episodic AM. The present study used the Children's Autobiographical Interview (CAI) to study episodic and semantic AM in 79 children aged 9 to 14 years, including 26 with early-treated congenital hypothyroidism (CH), 23 born to women with inadequately treated hypothyroidism during pregnancy (HYPO), and 30 typically developing controls. Results showed that relative to controls, CH and HYPO groups both exhibited weaknesses in episodic AM, but not semantic AM. In particular, CH and HYPO groups showed difficulty in recalling event details (i.e., the main happenings) and visual details from past experiences. Overall, this study highlights the importance of TH for early neurodevelopment and provides critical new insight into the effects of early treated TH deficiency on long-term memory performance. Furthermore, the present study indicates that the CAI is an effective tool for investigating episodic AM impairment in clinical pediatric populations. (JINS, 2013, 19, 1–11)