Reduced fetal ductus venosus shunt fraction is associated with adverse perinatal outcomes in pregnancy with pregestational diabetes mellitus

Purpose The purpose was to determine the fetal liver blood flow and identify whether diabetes mellitus complicates the ductus venosus (DV) shunt fraction and adverse outcomes in pregnancies. Methods We conducted a prospective longitudinal observational study including 188 pregnant women: group I – patients with pregestational DM (PGDM, n = 86), group II – patients with gestational DM (GDM, n = 44), group III - control (n = 58). Patients included in the study underwent ultrasound examination at 30 ^+ 0 − 41 ^+ 3 weeks of pregnancy. We evaluated volumetric blood flow adjusted to EFW (Q, ml/min/kg) for umbilical vein, DV, left and main portal vein. Relative risk was calculated for adverse pregnancy outcomes. Results There was a redistribution of volumetric blood flow to the fetal liver by decreasing the DV shunt fraction in PGDM pregnancies. These changes were characterized by an increase in left portal and total liver volumetric blood flow compared with GDM and control groups (p < 0.001). In some PGDM patients, the DV shunt fraction was pathologically reduced. A reduction in DV shunt fraction ≤16.5% was associated with an increased relative risk of preterm delivery (3.61), LGA-birth (1.64), neonatal adiposity (1.53), fetal hypoxia (3.47), emergency cesarean section (1.93), and neonatal intensive care unit stay more than 5 days (1.78). Conclusion Decreased DV shunt fraction reflects changes in fetal hemodynamics and may be an important marker of fetal adversity. A decrease in DV shunt fraction of less than 16.5% is associated with an increased risk of adverse perinatal outcomes in patients with PGDM.