Ductus venosus velocity ratios for prediction of neonatal cardiac dysfunction in early severe fetal growth restriction

Objectives To assess if fetal ductus venosus velocity ratios recorded within 24 h from birth are significantly different in severely growth restricted newborns with and without myocardial dysfunction. Methods Retrospective cohort study. From 2011 to 2015 we included singleton fetuses with estimated birthweight or fetal abdominal circumference ≤ 10th centile and umbilical artery pulsatility index (UA-PI) > 95th percentile, delivered between 26+0 and 34+0 weeks' gestation. Pregnancies complicated by fetal abnormalities or aneuploidy were excluded. Pulsatility index for veins (DV-PIV) and peak velocities of S-, D-, v- and a-waves were measured within 24 hours before delivery. Velocity ratios were converted into multiples of the median (MoM) adjusting for gestational age. DV-PIV was considered abnormal if ≥95th centile. Neonatal myocardial dysfunction was defined as need for inotropic support >24 hours after birth, within 3 days from delivery. Student's t-test was used for comparison of parametric continuous variables. Results The study population included 54 fetuses. There were 2/54 intrauterine deaths (IUD) and 10/52 neonatal deaths (NND). Inotropic support was needed in 12/52 cases. Abnormal DVPIV was not associated with an increased risk of neonatal myocardial dysfunction (relative risk =1.5; 95% Confidence Interval 0.75 to 3.3, p = 0.44). Newborns with myocardial dysfunction had lower mean v/D ratio [0.74 MoM, standard deviation (SD) 0.09 MoM vs 0.89MoM (0.04 SD); p = 0.04] and S/v ratio [0.58 MoM (SD 0.07 MoM) vs 0.78 MoM (0.04 SD); p = 0.02) when compared to newborns without myocardial dysfunction. Conclusions In severely growth restricted fetuses, ductus venosus velocity ratios correlate with neonatal myocardial dysfunction.