Chronic inhibition of COX-2 during gestation does not result in fetal DA constriction. Analysis of fetal DA on day 15 of gestation, 4 hours following administration of (a) vehicle or (b) COX-2–selective inhibitor SC-236. (c) Chronic administration (on gestation days 15–18) of SC-236 and fetal analysis 4 hours after the dose on gestation day 18. Scale bar, 100 μm.