Oral glyburide may be safe in pregnant type 2 diabetics. (Data Limited).

SAN FRANCISCO -- The oral diabetes drug glyburide is probably safe during pregnancy in women with type 2 diabetes, but those on other oral agents should be switched to insulin before pregnancy or as soon as possible after conception, Dr. Martin N. Montoro said at the annual scientific sessions of the American Diabetes Association.

More information is sorely needed about the possible effects of oral glucose-lowering agents during pregnancy.

Despite the fact that type 2 diabetes is a growing problem among women of childbearing age, there are virtually no prospective, randomized data to guide physicians about the safety of commonly used oral diabetes drugs on the developing fetus, said Dr. Montoro, who is professor of clinical medicine and ob.gyn. at the University of Southern California, Los Angeles.

Pregnant women have been routinely excluded from clinical trials, due largely to liability concerns of pharmaceutical companies, which would normally fund such trials, he noted.

On the flip side, abundant data clearly show that uncontrolled maternal diabetes is teratogenic. It appears that in many cases, adverse fetal outcomes that have been attributed to oral glucose-lowering agents--including various anomalies, stillbirths, macrosomia, and neonatal hypoglycemia--were probably due to the diabetes itself, he commented.

Insulin works, of course, but it's not usually an attractive option for women who are used to taking pills to control their diabetes.

Dr. Montoro offered his expert advice, based on mostly limited data from animal studies, anecdotal reports, and retrospective reviews.