Isolated premature restriction or closure of foramen ovale in fetuses: Echocardiographic characteristics and outcome

BACKGROUND: Premature restriction or closure of foramen ovale (FO) in otherwise structurally normal hearts may be associated with right ventricular dilation, tricuspid regurgitation, pericardial effusion, heart failure, even poor perinatal outcomes. Data about these rare conditions are lacking. METHODS: We retrospectively reviewed the echocardiographic records of 9704 fetuses seen from 2010 to 2014 in Beijing Anzhen Hospital, a regional and national referral center, to ascertain the presence of restriction or closure of FO. We collected the fetal echocardiography and perinatal outcome data for this group of fetuses with restriction or closure of FO. RESULTS: In this large, single-institution cohort (n = 9704), 6707 fetuses seen between 23 and 37 weeks of gestation had normal heart structures; of these, 60 (0.89%) had restrictive FO (rFO) and 5 (0.07%) had closure of FO (cFO). Fetal echocardiographic images showed right atrial dilation in 48 (73.84%), right ventricular dilation in 38 (58.46%), tricuspid regurgitation in 19 (29.23%), and pericardial effusion in 10 (15.38%). Also in this group, 50 (83.3%) with rFO and 4 (80.0%) with cFO had follow-up data. No prenatal deaths occurred in either the rFO or the cFO group, but the neonatal mortality included 1 in the rFO group and 2 in the cFO group. CONCLUSION: Premature rFO/cFO are rare in fetuses with otherwise structurally normal hearts. The fetal echocardiographic characteristics include right atrial and ventricular dilated, tricuspid regurgitation, and pericardial effusion. Most fetuses had a good outcome, although there was an association between rFO, especially cFO, with neonatal morality and complications (prematurity, maternal preeclampsia and placental abruption, hydrops fetalis, and necrotizing enterocolitis with perforation).