Is ondansetron safe to take for nausea while pregnant?

In severe cases: Most case reports and studies of ondansetron have not shown evidence of fetal malformations. A large study this year (2013) showed no evidence of increased spontaneous abortion, risk of stillbirth, preterm delivery, or low birth weight or small for gestational age babies. http://tinyurl.com/k6q5hr3 still, this medicine is usually reserved for more severe cases of hyperemesis gravidarum.