[Sirenomelia in one of the twins].

A case of rarely occurring malformation of the embryonal period of development, a diploid variant of sirenomelia in one of the twins, is described. Roentgenology revealed a paired set of bones of the extremities. There was aplasia of the external sex organs with formed gonads, atresia of the urethra and anus, aplasia of the renal arteries, hypoplasia of the right and aplasia of the left kidney, colonic-urinary bladder fistula. Operative intervention (epicystostomy, colostomy) was applied. The baby died on the 8th day with renal insufficiency and disorders of the cerebral circulation.