Characteristics of Isolated Ventricular Septal Defects Less Likely to Close In Utero

OBJECTIVES

To determine the characteristics of fetal ventricular septal defects (VSDs) that will be less likely to close prenatally.

METHODS

In this 4-year retrospective cohort study, 148 fetuses had a diagnosis of a VSD during a comprehensive fetal anatomy survey. The VSD diagnosis was confirmed by color and pulsed wave Doppler studies. These fetuses were followed monthly until their birth. They had postnatal echocardiography performed within 1 month of age to assess the persistence of a VSD. Fisher exact, Wilcoxon rank sum, and log rank tests and bivariate and multivariate logistic regressions were used to examine the association of each individual variable with prenatal VSD closure.

RESULTS

One hundred twenty-five of 148 fetuses (84%) had prenatal VSD closure at a mean gestational age ± SD of 26.9 ± 4.5 weeks. Fetuses with a persistent VSD more frequently had other cardiac defects than the closed VSD group (12 of 23 versus 5 of 125; P < .001). Fetuses having a persistent VSD more frequently had an abnormal karyotype (9 of 23 versus 5 of 125; P < .001). The persistent VSDs were larger in their initial size (5.9 ± 8.4 mm versus 2.7 ± 0.8 mm; P = .002) and in their maximal prenatal size (6.0 ± 9.1 mm versus 2.9 ± 0.9 mm; P < .001). The presence of associated cardiac defects (adjusted odds ratio = 0.071; P = .031) and an abnormal karyotype (adjusted odds ratio = 0.058; P = .021) were significantly associated with a lower likelihood of prenatal VSD closure. All VSDs with a maximal size of 2 mm or less closed prenatally.

CONCLUSIONS

Fetuses with a complex cardiac defect or an abnormal karyotype were less likely to have prenatal VSD closure.