No abstract

Redundant foramen ovale (RFO) is defined as an abnormally redundant foramen ovale flap that extends at least halfway across the left atrium. The exact pathogenesis is unknown. Premature, isolated, in utero RFO is rare. The prevalence in general population is unknown as it may be easily ignored on routine fetal echocardiography. The reported frequency in fetuses referred for echocardiographic examination is 0.6-1.7%. It can cause right ventricular volume overload leading to fetal hydrops and subsequent cardiac failure. In such cases, prompt delivery depending on fetal gestational age may be instrumental for the survival of the neonate. 67% can develop cardiac arrhythmias which generally resolves at birth. The most common is premature atrial contractions though rarely, supraventricular tachycardia can also occur. RFO usually occurs in isolation but when associated with congenital heart disease, it carries a poor prognosis. Several series have reported redundant foramen ovale in echocardiographic and autopsy findings in children and adults but only few reports on the antenatal detection of isolated RFO has been described. We discuss two prenatal cases of isolated redundant foramen ovale diagnosed in the third trimester. They were followed up two weekly without development of any complications and delivered at term. After delivery, the infants had no history or symptoms of cardiac distress. Echocardiography showed a structurally normal heart. Hence, if there are no associated anomalies in a case of redundant foramen ovale, the prenatal management need not be altered.

The objective of our study was to appraise the incidence and significance of persistent right umbilical vein (PRUV), the most common foetal venous aberration. Based on a south Indian antenatal cohort, we identified 23 cases of PRUV amongst 20,452 foetuses of consecutive pregnancies, from 2009 to 2014, yielding an incidence of 1 in 889 total births (0.11%). The median maternal age was 24 (IQR, 22-26) years, and median gestational age at diagnosis was 23 (IQR, 22-24) weeks. Intrahepatic drainage of PRUV was seen in 91.3% cases. In three cases (13%), ductus venosus was absent. In 52.2% of the cases, additional major abnormalities were observed - predominantly cardiovascular (39.1%). The common minor marker was single umbilical artery (13%). The karyotype was found to be normal in six cases (26%) which underwent invasive testing. When associated anomalies were inconsequential or absent, the postnatal outcome was good, which reflected in 60.9% of our cases.

The incidence of conjoined twins as reported in a worldwide epidemiological study is 1.47 per 100,000 births. It varies from 1 in 45,000-200,000 births. Conjoined twins following assisted reproduction are even rarer and we report one such case. A 36-year-old woman who conceived by intracytoplasmic sperm injection, was referred to the feto-maternal unit for nuchal translucency scan. A diagnosis of thoracopagus conjoined twins was made on ultrasound at 12 weeks 3 days of gestation. The couple was counseled in detail and they opted for termination. Pregnancy was terminated medically and the ultrasound diagnosis was confirmed. Assisted reproduction techniques involve a risk of conjoined twins and the present case report supports this. Early diagnosis of conjoined twins and determination of the type of fusion is possible. This aids in discussing the prognosis and counseling the couple regarding options of termination or continuation of pregnancy.

The anatomic causes for fetal right atrial dilatation with tricuspid regurgitation include Ebstein anomaly, tricuspid dysplasia, unguarded tricuspid orifice, and Uhl anomaly. Unguarded tricuspid orifice is characterized by complete or partial agenesis of the tricuspid valvular and subvalvular structures. It is commonly associated with pulmonary atresia. Its prenatal diagnosis is usually associated with unfavorable prognosis. We present a prenatally diagnosed case of fetal unguarded tricuspid orifice with description of its diagnostic workup, along with a review of literature, to enhance the understanding of this rarely reported entity. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:370-374, 2017.