The sensitive period and malformation syndrome produced by thalidomide in the crab eating monkey (Macaca fascicularis)

The day of mating was designated as day zero of pregnancy. The pregnant animals received 5, 10, or 30 mg/kg of thalidomide orally, either as single doses on days 24, 25, 26, 27, 28, 29, or 51, or as multiple doses on days 25-27 of pregnancy. No malformations were observed following treatment on days 24, 29, and 51 of pregnancy. Malformations of the forelimbs were observed on days 25, 26, and 27, and both fore- and hindlimb malformations were observed following treatment on day 28. The malformations were characterized by total absence (amelia) or partial absence (meromelia) of the free limb.