Micronase, Similar Diabetes Drugs May Cross Placenta And Affect Unborn Children: Study

The findings of a new study raise concerns about the use of a certain class of diabetes drugs during pregnancy, finding that the medications may transport across the placenta and potentially impact a developing fetus. 

Canadian researchers warn that glyburide, the active ingredient in the diabetes drugs Micronase, DiaBeta, and Glynase, was found in umbilical cord blood in recent study. While the diabetes drugs have not previously been linked to a risk of birth defects, the findings raise questions about the use of the medications by pregnant women.

Findings of the prospective observational study were published in the March 2015 issue of the medical journal Obstetrics & Gynecology, examining the immediate post-delivery, maternal and umbilical concentrations of Micronase amone women with gestational diabetes mellitus who are using the medication.

Glyburide, also known as glibenclaimide, is used to treat type 2 diabetes. It belongs to a class of drugs known as sulfonylurea, which increase the amount of insulin released by the pancreas. Drugs using glyburide currently have a pregnancy risk rating of category B and Category C, meaning there is no evidence of risk in humans, but that the existence of risks have not yet been ruled out.

“There were statistically significant relationships between total maternal glyburide dose and maternal glyburide levels and between total maternal glyburide dose and umbilical glyburide levels,” the researchers found. “However, we observed wide variability in maternal and umbilical glyburide levels at both extremes of the total glyburide dose.”

Researchers found that 79% of the cord blood samples had glyburide levels of less than 10 mg/mL, but 37% of the cord blood samples had levels of the drug that were higher than the levels detected in the mother.

Placenta transport of drugs, where the drug appears to have crossed the placenta to potentially come into contact with a developing fetus, is often the first indicator that a drug may impact the development of an unborn child.

The latest study does not link the drugs to any increased rate of birth defects or birth malformations, but may be an indicator that more studies into potential Micronase birth defect risks are needed.