Six fetuses with normal chromosomes were found to have severe craniofacial, limb, and visceral malformations during the second trimester of pregnancy. Two of these fetuses were monozygotic twins while a third one had a healthy dizygotic twin brother. A case with familial recurrence was also observed. Autopsy and skeletal radiographs suggested several diagnoses such as neural tube defect with limb defects or XK aprosencephaly. The development of these severe conditions in monozygotic twins and familial recurrence emphasize the difficulties of genetic counseling in such situations. These cases may suggest autosomal recessive inheritance.