The antepartum findings of conjoined twins

Abstract

Various estimates abound as to the incidence of conjoined (Siamese) twins, but they are indeed uncommon. The probability of their occurance has been calculated to be once in every 12,000 to once in every 100,000 deliveries. Although uncommon, the antepartum diagnosis can be extremely important to the twins and the mother, if only to spare the trauma of a trial by labor. The findings, both radiographic and ultrasonic, are presented herein.

Malformações Fetais em Gestação Múltipla

“…Os gêmeos unidos são classificados, de acordo com o local do corpo onde a união fetal é dominante, em cinco tipos predominantes: toracópagos (tórax, 30-40%), onfalópa-gos (abdome, 25-30%), piópagos (sacro, 10-20%), isquiópagos (pelve 6-20%) e craniópagos (cabeça, 2-16%). O diagnóstico ultra-sonográfico pré-natal desta anomalia foi relatado primeiramente em 1977 14 . Desde este relato, numerosos casos têm sido descritos na literatura [15][16][17] .…”

Asymmetric parasitic dicephalus conjoined twins

“…Whenever monozygotic twinning is observed, conjoining should be suspected. Wilson et al 8 suggested that the presence of polyhydramnios and both twins in breech or in face-to-face position should alert the sonographer to the possibility of conjoined twins. Koontz et al 9 suggested that some other sonographic findings are also associated with conjoined twins.…”

Dicephalus Tribrachius: Prenatal Diagnosis and Management

“…The first reported case of conjoined twins was recorded in A.D. 1 100 (12) and the first recorded case diagnosed prenatally by ultrasound B-scan was in 1977 (18). The malformation is thought to result from an incomplete, delayed fission of the inner cell mass, which occurs after the 14th day of fertilization (16).…”