Metabolic diseases in pregnant mothers can negatively influence their offspring and cause an increased risk of some conditions. The group of the Center for Biomedical Research in Network for Diabetes and Associated Metabolic Diseases (CIBERDEM) led by Héctor Escobar Morreale at the Ramón y Cajal Hospital in Madrid has reviewed current evidence on the effects of thyroid alterations and maternal hyperglycemia on fetal programming, specifically on cognitive function and carbohydrate metabolism in the offspring.
Fetal programming is an adaptation process whereby nutrition and other environmental factors alter developmental pathways during the period of prenatal growth, thereby inducing changes in postnatal metabolism and adult susceptibility to chronic disease.
This work, published in the journal Fertility and Sterility, demonstrates the need for an early diagnosis and proper management of endocrine complications in pregnancy in order to prevent any of the negative consequences for children.
According to Escobar, who carried out the study with Lía Nattero and Manuel Luque, it is essential to train health personnel involved in the care of pregnant women in the management of these clinical situations, since these complications can go unnoticed if they are not monitored actively.
During the first phase of pregnancy, the transfer of thyroid hormones to the fetus is of paramount importance for proper neurological development and, at this stage, severe maternal thyroid dysfunction, particularly iodine deficiency, can prove fatal producing irreversible neurological sequelae included in the spectrum of neurological cretinism. However, fetal exposure to a mild hormone dysfunction can also cause more subtle neurological and behavioral disorders.
The work concludes that a thyroid hormone supply from very early stages in a suitable sequence in space and time is a necessary condition for normal fetal neurological development. Therefore, overt hypothyroidism and iodine deficiency need early identification and management, to avoid problems in the offspring.
Glucose, overweight and cardiovascular risk
The researchers emphasize the importance of monitoring episodes of maternal hyperglycemia secondary to the presence of pregestational or gestational diabetes.
The risk of alterations in the offspring can occur even in the lowest degrees of maternal hyperglycemia.
For Escobar, “this is another relatively frequent situation in which fetal development takes place in a hostile environment, and there is an increased risk of neurodevelopmental disorders, abnormal glucose metabolism, overweight and other cardiovascular risk factors in adult life.”
Also, fetal exposure to hyperglycemia due to type 1 diabetes mellitus or gestational diabetes is associated with postnatal metabolic effects. The findings highlighted in this study show that the risk of alterations in the offspring can occur even in the lowest degrees of maternal hyperglycemia.
In addition, it is evident that the risk of overweight and obesity is higher in pregnant women with type 1 diabetes mellitus than in gestational diabetes. Maternal glycemic control through diets or insulin therapies seems to improve metabolic outcomes in the offspring.