Diprosopus Associated with Neural Tube Defect and Facial Cleft in theFirst Trimester

Abstract

We report a case of diprosopus presenting with increased nuchal translucency of 5.3 mm at 14 weeks of gestation. Ultrasonographically, the fetus presented with micrognathia, anterior indentation of the cephalic pole, abnormal cerebral hemispheres with a cystic 4th ventricle and angulation of the spine. The fetal karyotype was normal (46,XX). Following termination of pregnancy, postmortem examination established the diagnosis of diprosopus tetraophthalmus with facial cleft of the 2 faces.

Prenatal Diagnosis of Monocephalic Bifacial Tetraophthalmic Diprosopus (Conjoined Twin)

“…The previous five were reported by other authors [2][3][4][5][6] . Some cases have been reported as early as in the first trimester [7,8] , but the diagnosis was made on the postmortem pathologic examinations of aborted products of conception [9] .…”

A Very Rare Form of Conjoined Twinning: Diprosopus Twins Diagnosed in the First Trimester of Pregnancy by Transvaginal Ultrasonography

“…It is almost always associated with other anomalies such as neural tube defect, diaphragmatic hernia or cardiac malformations. 3 Other commonly associated abnormalities include cleft lip and palate. A strong association between diprosopus and neural tube defects supports the hypothesis that conjoined twins and neural tube defects may share some pathological mechanism secondary to a failure of the rostral neuropore to close.…”

A Systematic Approach to First-trimester Ultrasound Assessment of Twins

“…36,37 SIXTH STEP: ASSESS FOR MAJOR CONGENITAL ANOMALIES Increased incidence of congenital malformations has been reported in twins, especially monochorionic twins, compared with singletons. [38][39][40][41] Cardiac abnormalities account for 68% of all the structural defects in twins. 41,42 Although an accurate diagnosis is difficult before the second trimester of pregnancy, cardiac anomalies are more likely when abnormal NT measurements and ductus venosus blood flow are detected.…”