Prenatal characteristics and postnatal outcomes of small fetal hepatic lesions: a retrospective cohort study

Objective: To describe prenatal characteristics and postnatal outcomes of fetal hepatic lesions diagnosed on prenatal ultrasound and to identify prognostic factors of this condition. Methods: A retrospective study was conducted in a cohort of fetuses diagnosed with hepatic lesions between 2011 and 2023 at a tertiary referral center. Prenatal and postnatal data were collected, including lesion type, size, gestational age at detection, associated anomalies, genetic abnormalities, growth restriction and pregnancy outcomes. Postnatal follow-up included imaging, lesion resolution and overall health status. Results: 65 fetuses were identified. Most lesions were echogenic (n=55); a minority were cystic (n=7), mixed (n=1) or subcapsular hematomas (n=2). Multiple lesions were present in 38%. Stillbirths, including fetal death and pregnancy termination, occurred in 18%, predominantly in the setting of major associated anomalies, fetal growth restriction and/or genetic abnormalities. Of 48 liveborn infants, 96% were healthy at discharge. Among 31 infants followed postnatally, 75% showed lesion resolution by 21 months. At the 5-year median follow-up, 79% were healthy. Echogenic lesions were more common in healthy infants, while a cystic component was associated with a higher rate of concurrent clinically significant health conditions, although liver function was typically normal. Conclusion: Isolated small echogenic fetal hepatic lesions display a favorable prognosis with spontaneous resolution in most cases. Adverse pregnancy outcomes are common in cases with associated anomalies, fetal growth restriction and genetic abnormalities; therefore, counseling should be guided by a comprehensive anomaly assessment and appropriate genetic evaluation.