Foetal head growth retardation due to antiepileptic drugs: with reference to GH, TSH, T4, T3 and reverse T3 concentrations.

To study the mechanisms of inhibitory action of antiepileptic drugs on foetal head growth, determinations were made of the growth hormone, thyrotropin and thyroid hormone levels in the sera of pregnant women, and the correlations between each hormone concentration and the foetal head circumference were studied. The thyroxine level decreased in the maternal serum and in the cord blood, and the thyrotropin level also became lower in the epileptic mother taking antiepileptic drugs. The growth hormone level in the umbilical vein sample of the epileptic mother was lower than that in the controls. The correlations between the head circumference of an infant at delivery and the decreased levels of the hormones seemed to indicate that a decrease in the thyroxine level, caused by antiepileptic drugs, produced the foetal head growth retardation.