Prenatal diagnosis of anterior duplication anomaly (dicephalus diauchenos) by ultrasonography.

A 29 year old gravida 3, para 1 was referred in the 32nd pregnancy week for ultrasonography when a twin pregnancy was suspected. We found a fetal duplication with two heads in parallel position, biparietal diameter 81 mm (Fig. 1), a joint thoracic cavity measuring 86 x 92 mm (Fig. 2), reduced amniotic liquid and decreased spontaneous movements. The pelvic radiogram confirmed our suspension of an anterior duplication anomaly and showed only two arms and two legs for both fetuses but brought no additional information. The amniofetography failed. The contrast media ended up in the joint peritoneal cavity of the fetuses (Fig. 3). Delivery was in the 36th week by Cesarean section. The weight of the conjoint twins (Fig. 4) was 3210 grams, length 43 cm, and head circumference of each was 32 cm. Both fetuses showed independent respiratory movements and both briefly cried. Death occurred after 12 hours. Fig. 5 shows remnants of a scapula and Fig. 6 demonstrates a stump like leg remanent. Our prenatal diagnosis of an anterior duplication was confirmed by the autopsy. After a prenatal diagnosis of a duplication anomaly we recommend Cesarean section in term pregnancies. Considerations when deciding on the management of the pregnancy should include survival chances following possible surgical separation. If the diagnosis if made before the 24th week termination of the pregnancy might be considered.