Which statement about oral hypoglycaemic agents in pregnancy is correct?
- A Metformin does not cross the placenta
- B Glibenclamide has negligible transplacental passage because of high protein binding and rapid hepatic clearance ✓
- C Both metformin and glibenclamide are teratogenic in the first trimester
- D Sulfonylureas cause neonatal hypoglycaemia only via maternal hyperglycaemia
Correct answer: B. Glibenclamide has negligible transplacental passage because of high protein binding and rapid hepatic clearance
Explanation
Glibenclamide (glyburide) is highly protein bound and rapidly metabolised, so cord blood levels are minimal relative to maternal levels. Metformin, in contrast, crosses the placenta freely, exposing the fetus directly. Neither drug is established as teratogenic. Neonatal hypoglycaemia after sulfonylurea exposure results from fetal pancreatic stimulation by the drug itself, not merely maternal glycaemia, making that option incorrect.
Reference: Williams Obstetrics, 26th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.