The effect of thalidomide intake during 113 human pregnancies

Thalidomide was taken by 113 pregnant women during August 1959 to December 1961. Of these, only seven women took the drug during the critical period, i.e., between the 34th and 50th day after the last menstrual period. Three of them delivered malformed babies, including one spontaneously aborted by the 101st day after the last menstrual period. The remaining four women had children without apparent malformations. Two of the four children were reexamined by the age of 11 years. Rentgenograms were taken of the entire skeleton, and no malformation attributable to thalidomide was found. The first day of thalidomide intake in these four cases ranged from the 46th–49th day after the last menstrual period. It seems that a “thalidomide-resistant pregnancy” occurred in some of the cases in which the drug was taken only by the 46th day or later in the critical period. In the case of two other women, thalidomide was taken earlier than the critical period: one by the 19th day and the other by the 23rd. The former underwent an induced abortion, and the latter had a spontaneous abortion by the 49th day. In the remaining 104 cases, in which thalidomide was prescribed later than the critical period, the offspring were apparently normal, except for one case of anal stenosis.