Alpha-fetoprotein in diabetic pregnancy. A reassessment

We correlated glycosylated hemoglobin (HbA1) with maternal serum alpha-fetoprotein (MSAFP) in 92 and amniotic fluid AFP (AFAFP) in 27 patients with pregestational and gestational diabetes. MSAFP and AFAFP were measured between 15 and 20 weeks and correlated with HbA1. In group 1, HbA1 was measured at < or = 12 weeks' gestation; in group 2, it was measured 0-6 weeks before MSAFP measurement; and in group 3, it was measured within 6 weeks after MSAFP. Mean MSAFP was 1.02 +/- 0.77 multiples of the median (MOM) (+/- SD) in all diabetics, 1.1 +/- 0.93 MOM in gestational diabetics and 0.89 +/- 0.33 MOM in pregestational diabetics (P = NS). There was no correlation between MSAFP and HbA1 in groups 1-3. Patients with HbA1 > 9 g% had a mean MSAFP of 0.84 MOM as compared to 0.85 MOM in those with HbA1 < 9 g% (P = NS). AFAFP values were within normal limits even in patients with HbA1 > 9 g% in early pregnancy (n = 8). No significant decrease in MSAFP was seen in pregestational diabetics, and no correlation was seen with HbA1 levels. AFAFP levels were unchanged in diabetics.