Conjoined Twinning in Mammalian Teratology

Three cases of conjoined twinning have been found in the golden hamster following treatment of the mothers with three different known teratogens: vitamin A, dimethyl sulfoxide (DMSO), and urethan. The twinning impetus which results in monozygous (MZ) twinning may thought of as an abnormal phenomenon in itself. This form of twinning in many cases is associated with a high intrauterine mortality, a high rate of situs inversus viscerum, severe developmental malformations associated with placental vascular abnormalities, discordance in organ development, and conjoined twinning.