Neonatal patent DA following chronic COX-2 inhibition. Maternal administration of (a) vehicle, (b) COX-1–selective inhibitor SC-560, or (c–f) COX-2–selective inhibitor SC-236 on gestation days 15–18. Histological DA analysis of wild-type neonates sacrificed 5 hours after birth is shown in a–c. d–f shows postmortem DA analysis of wild-type neonates that died (d) between 5 and 24 hours after birth, (e) between 24 and 48 hours after birth, or (f) were sacrificed after 48 hours for comparison. Scale bar, 100 μm.