Impact of prenatal diagnosis of fetus-in-fetu.

Fetus in fetu (FIF) is an extremely rare condition (1/500,000 live births) in which a fetiform structure is incorporated into the body of its twin. FIF can be a diagnostic dilemma due to its similarity to a teratoma, but identification of FIF is important for subsequent medical and surgical management. We compare two cases of fetal masses diagnosed on prenatal imaging that were later identified as FIF through further radiological, surgical, and pathologic evaluation. We use these cases to illustrate key pre- and postnatal features of FIF and highlight the benefits of prenatal detection and follow-up for postnatal management.

Abdominal wall defects and congenital heart disease.

OBJECTIVES: To determine the incidence of cardiac disease associated with abdominal wall defects of fetuses and associated parameters including maternal age, sex, gestational age at delivery, outcome, karyotypes, Apgar scores and associated congenital anomalies. METHODS: This was a retrospective study of fetuses with a prenatal diagnosis of gastroschisis or omphalocele. The Maternal-Fetal Medicine Fetal Therapy (MFM) database was reviewed for all fetuses with abdominal wall defects identified prenatally. All available MFM records, fetal echocardiograms, neonatal echocardiograms and neonatal charts were reviewed for the types of abdominal wall defects and associated cardiac disease identified by ultrasound. Other parameters reviewed included: maternal age, sex, gestational age at delivery, outcome, karyotypes (when available), Apgar scores and associated congenital abnormalities. RESULTS: Forty-eight fetuses with an abdominal wall defect and cardiac disease findings were identified. Of these fetuses 26 had gastroschisis and 22 had omphalocele. The mean maternal age was 24.0 +/- 5.40 years in the gastroschisis and 29.2 +/- 7.23 years in the omphalocele group (P < 0.01). Differences in mean gestational age at delivery, mean birth weight and median Apgar scores at 1 and 5 min were not statistically significant. Abnormal cardiac findings were seen in 4/26 (15%) cases of gastroschisis and included one case of peripheral pulmonary stenosis, two cases of supraventricular tachycardia and one case of persistent pulmonary hypertension (PPHN) of the newborn. Abnormal cardiac findings were seen in 10/22 (45%) cases of omphalocele and included one muscular ventricular septal defect, two atrial septal defects of the secundum variety, one ectopia cordis, one coarctation of the aorta, one dysplasia of the tricuspid valve, one large pericardial effusion and four cases of PPHN. CONCLUSIONS: Fetuses with omphalocele appear to have an increased risk not only of congenital heart disease (CHD) but also of perinatal cardiac abnormalities, especially PPHN. A prenatal maternal hyperoxia test may be of predictive value in determining which patients may develop PPHN. The fact that both CHD and PPHN are increased in fetuses with abdominal wall defects may be of value in counseling parents prenatally, and stresses the importance of performing echocardiography both prenatally and postnatally in these cases.