Somatic growth trajectory in the fetus with hypoplastic left heart syndrome

BACKGROUND: Fetal growth abnormalities in hypoplastic left heart syndrome (HLHS) have been documented primarily by birth measurements. Fetal growth trajectory has not been described. We hypothesized that fetal growth trajectory declines across late gestation in this population. METHODS: Infants with a prenatal diagnosis of HLHS and no history of prematurity or a genetic syndrome were identified. Fetal ultrasound measurements and birth anthropometrics were obtained from clinical records. z-Scores for estimated fetal weight (EFWz) and birth weight (BWTz) were compared. BWTz for three neonatal standards were compared. RESULTS: Paired fetal and neonatal data were identified in 33 cases of HLHS. Mean gestational age at ultrasound and birth were 27 and 38 wk, respectively. BWTz was lower than EFWz by a mean of 0.82 (SD: 0.72, P < 0.0001), with 64% of subjects demonstrating a decrease in z-score of >0.5. Umbilical artery (UA) Doppler found no evidence of significant placental insufficiency. Modest differences in BWTz were seen across BWT standards in this cohort. CONCLUSION: The majority of fetuses with HLHS demonstrate decreased growth velocity during later pregnancy, suggesting growth abnormalities manifest in utero. The potential relationship to future clinical outcomes warrants further study.