Prior GDM? Treat without screening.

AMSTERDAM -- Seeing and presumptively treating all women with previous gestational diabetes mellitus for GDM early in their subsequent pregnancies--without rescreening them--is likely to improve maternal and fetal outcomes, Dr. Christina S. Cotzias said at the annual meeting of the European Association for the Study of Diabetes.

Recurrence rates of GDM in subsequent pregnancies among women who had the condition in a previous pregnancy range from about 30% to 70%, depending on the population studied. In general, the heavier and less white the population, the greater the GDM recurrence rate. And among women who do have GDM recurrence, some studies have suggested that glucose intolerance may occur earlier in subsequent pregnancies than in the initial one, said Dr. Cotzias of the department of obstetrics and gynecology at West Middlesex University Hospital, Isle-worth, England.

The Middlesex hospital's obstetric unit serves a multiethnic community with a large Asian population. A retrospective case note analysis was performed for 419 women who were treated for GDM at the hospital during 2000-2005, of whom 123 (29%) had GDM in a prior pregnancy and 296 (71%) did not. Those with previous GDM were significantly older (median age 34 vs. 32 years), and heavier (BMI 29 vs. 27 kg/[m.sup.2]), but there were no differences in ethnicity between the groups, both of which were approximately one-half Asian, one-quarter white, and about one-fifth black; the remainder were other ethnicities.

Hemoglobin [A.sub.1c] levels were significantly higher among the women with previous GDM: 27% were at or above 7%, compared with 15% among those with newly diagnosed GDM. The women with previous GDM were much more likely to require insulin therapy (67% vs. 47%) and to be started on insulin sooner (25 vs. 34 weeks' gestation).

Of the 82 women in the previous GDM group who required insulin, nearly two-thirds (48, or 59%) needed it prior to 28 weeks' gestation, the time of routine GDM screening. "If we waited to screen those women, we would miss nearly 60% of those who need insulin before 28 weeks," Dr. Cotzias noted.

Exactly half of each group had spontaneous vaginal delivery; cesarean section rates also did not differ significantly in the two groups (44% of those with previous GDM and 40% of those without). There were no significant differences between the two groups in any neonatal outcome, including shoulder dystocia, stillbirth, neonatal abnormality, or birth weight.

Of the women who came back for follow up after delivery, 23% of 66 with previous GDM and 22% of the 188 without--an insignificant difference--had abnormal glucose tolerance test results.

"I extrapolate the findings to suggest that if I left these women until 28 weeks' gestation and then started [treatment], I would have missed the boat and had worse outcomes. I can't prove it, but that's what the data suggest," Dr. Cotzias said.

BY MIRIAM E. TUCKER

Senior Writer