Association of Fetal Intrahepatic Umbilical-Portal Anastomosis Type with Late-Onset Fetal Growth Restriction and...

Objective: To evaluate whether fetal intrahepatic umbilical-portal anastomosis type is associated with late-onset fetal growth restriction (FGR) and adverse neonatal outcomes. Methods: This prospective, single-center case-control study included 160 singleton pregnancies in the third trimester: 80 with late-onset FGR defined according to Delphi consensus criteria and 80 appropriate-for-gestational-age (AGA) controls. Umbilical-portal anastomosis was assessed by ultrasound and classified as T-shaped, X-shaped, or H-shaped. Maternal, sonographic, obstetric, and neonatal data were recorded. Multivariable logistic regression evaluated associations with FGR, and Firth's penalized regression assessed composite adverse perinatal outcome (CAPO) within the FGR group. Results: X-shaped anastomosis predominated in FGR (55.0%; T-shaped, 26.3%; H-shaped, 18.8%), whereas T-shaped was most common in controls (61.3%; X-shaped, 23.8%; H-shaped, 15.0%). FGR cases showed higher umbilical artery pulsatility index, lower middle cerebral artery pulsatility index and cerebroplacental ratio, earlier delivery, lower birth weight, and higher rates of NICU (neonatal intensive care unit) admission, transient tachypnea of the newborn, and CAPO (35% vs. 15%). Both X-shaped and H-shaped types were independently associated with FGR, with a stronger effect for X-shaped (adjusted odds ratio [aOR], 5.27 vs. 2.85). Predicted probabilities increased stepwise from T-shaped to H-shaped to X-shaped (30.3%, 55.3%, and 69.6%). Within the FGR group, only X-shaped anastomosis was independently associated with CAPO, whereas Doppler indices were not discriminatory. Conclusions: X-shaped fetal intrahepatic umbilical-portal anastomosis was independently associated with both late-onset FGR and adverse neonatal outcome. Intrahepatic vascular configuration may provide additional value beyond conventional fetal biometry and arterial Doppler in risk stratification.