Evaluation of Hemodynamic Changes in Fetuses With Isolated Mild‐to‐Moderate Ventriculomegaly by Transabdominal Ultrasound

OBJECTIVES: To investigate fetal hemodynamic alterations using transabdominal ultrasound in fetuses with isolated mild‐to‐moderate ventriculomegaly (VM). METHODS: Fetuses diagnosed with isolated mild‐to‐moderate VM by transabdominal ultrasound were evaluated for hemodynamic changes, including changes in fetal cardiac function, the umbilical artery, the ductus venosus, and the middle cerebral artery. The fetuses with isolated mild‐to‐moderate VM were divided into 2 groups, namely, before 32 weeks’ gestation (20 weeks–31 weeks 6 days) and after 32 weeks’ gestation (32–38 weeks), and matched to corresponding healthy control fetuses. RESULTS: The 53 fetuses with VM before 32 weeks had a longer mean isovolumetric relaxation time (IRT; mean ± SD, 42.9 ± 6.8 versus 40.4 ± 5.0 milliseconds; P < .05) and an apparently higher modified myocardial performance index 0.46 ± 0.06 versus 0.43 ± 0.05; P < .01) than the healthy control fetuses. The 43 fetuses with VM after 32 weeks had a significantly longer mean IRT (45.5 ± 6.7 versus 40.9 ± 7.2 milliseconds; P < .01) and a lower UA pulsatility index (0.81 ± 0.13 versus 0.89 ± 0.11; P < .01). The optimal cutoff levels for the IRT in the prediction of adverse perinatal outcomes were 40 and 43 milliseconds before and after 32 weeks, respectively (sensitivity, 100% versus 100%; specificity, 40.4% versus 50.0%; area under the curve, 0.601 versus 0.748; 95% confidence interval, 0.457–0.733 versus 0.590–0.869; P = .291 versus .005). CONCLUSIONS: Some fetuses with isolated mild‐to‐moderate VM may have impaired cardiac function, characterized by a higher modified myocardial performance index or longer IRT. This finding might be useful for improving fetal surveillance.