Endocrine balance as a factor in the etiology of the fetal alcohol syndrome.

It is well documented that children with the fetal alcohol syndrome are a direct consequence of heavy maternal ethanol consumption during pregnancy. The mechanism by which ethanol exerts its teratogenic effect is however, far from understood. Recent experimental evidence has shown alcohol to have a direct inhibitory effect on embryogenesis. Little information, however, is available concerning other factors associated with maternal drinking which may contribute to abnormal fetal development. Proper materno-fetal hormonal balance is essential to insure successful pregnancy outcome. Of particular importance with respect to normal fetal development, are the levels of placental tropic hormones; pituitary hormones such as prolactin and oxytocin; adrenal cortical hormones; both maternal and fetal thyroid hormones; maternal and fetal sex hormones; and maternal insulin. Ethanol alters the levels of a variety of hormones associated with the hypothalamic/pituitary-gonadal, -adrenal and -thyroid axes. Many of these alterations have been observed in the male, however, with little data available on the female. In spite of the known adverse effect of ethanol on certain aspects of female reproductive function, few if any studies have examined the effects of alcohol ingestion during pregnancy on maternal endocrine balance. It is hoped that the present review will provide a rationale for the examination of alcohol effects on maternal endocrine hormones, as well as to provide possible target areas with respect to fetal development subsequent to ethanol-induced endocrine imbalance.