Do antiepileptic drugs cause two vessel umbilical cord in fetuses exposed in the womb ?

Coincidence: Single umbilical artery ( two vessel cord) is usually a random occurrence.

AED's in pregnancy: Ob's, perinatologists, neurologists & genetic counselors often work together for the safety & health of mom & fetus; e.g. Monitoring blood levels of meds, checking mom's mthfr gene for folate (folic acid) metabolism, advising about the 6% risk of fetal effects, monitoring fetal growth & organ development on ultrasound & echo. A 2-vessel cord occurs in ~ 1.5% of all fetuses; 75-80% of the time it's fine.