Non-suppressible insulin-like activity during pregnancy in women with diabetes mellitus.

Serum levels of the growth factor non-suppressible insulin-like activity (NSILA-S) have been measured in eleven pregnant women with diabetes mellitus during pregnancy and immediately (2 days) after birth. A significant increase in mean levels was observed with increasing gestation, reaching a peak at the time of delivery and subsequently returning to non-pregnant levels within 2 days. The NSILA-S levels in diabetic pregnancies were not different from those in non-diabetic pregnancies and there were no significant correlations between NSILA-S and birth weight, maternal diabetic control, age or duration of diabetes or the treatment required. The physiological role of high NSILA-S levels during pregnancy still requires elucidation.