Prenatal diagnosis of monocephalic bifacial tetraophthalmic diprosopus (conjoined twin).

A case of diprosopus twinning which is rare conjoined twinning is reported prenatally at 22 weeks' gestation. 2D ultrasound examinations showed duplication of the craniofacial structures with four hemispheres, two cerebella and two thalami. There were three orbits two external ears, two noses, fused adjacent maxilla and two oral cavities with two fused oral opening and two jaws. The woman did not consent to any further investigations and the pregnancy was terminated. The postmortem examination confirmed the diagnosis in a male fetus with a crown-rump length of 155 mm, weighing 450 g. The body appeared normal except for a small poorly formed rudiment of a supernumerary digit next to the thumb of the right hand. The ultrasound examination and postmortem finding of this case is described with a short review of the literature.