A child showing multiple congenital anomalies was born to a woman with Hodgkin's disease who was treated with cyclophosphamide during pregnancy. It is probable that the alkylating agent administered during the first trimester played a significant teratogenic role. Alkylating agents act as teratogens in animals but have not been demonstrated previously as a cause of fetal abnormalities in humans.
Greenberg LH, Verdes P, Tanaka KR. Congenital Anomalies Probably Induced by Cyclophosphamide. JAMA. 1964;188(5):423-426. doi:10.1001/jama.1964.03060310023005