P0756 - Relationship between intracranial abnormalities in premature infants with intrauterine growth restriction and fetal Doppler parameters

Purpose: Intrauterine growth restriction (IUGR) is one of the leading causes of perinatal and neonatal morbidity and mortality. Although abnormal umbilical artery blood flow has been associated with poor outcomes, it is unclear if Doppler patterns are associated with a higher risk of intracranial abnormalities. The purpose of this study is to determine the primary composite outcome of death, severe intraventricular hemorrhage (IVH) or periventricular leukomalacia (PVL) in premature IUGR infants stratified by their most severe fetal Doppler patterns.

Methods: This is a retrospective cohort study including infants < 32 weeks’ gestation born between January 2016 and December 2018 with fetal IUGR defined as weight, abdominal circumference or length ≤ 10th% admitted to a level IV NICU. Singleton and twin gestations were included; infants with congenital malformations or chromosomal abnormalities were excluded. Infants were stratified by their most severe fetal Doppler pattern including group 1: normal, group 2: elevated systolic/diastolic ratio (S/D) or absent end diastolic flow (AEDF) in the umbilical artery (UA) and group 3: reversed end diastolic flow (REDF) in the UA or abnormal flow in the ductus venosus (DV). Severe IVH was defined as grade 3 or 4. Logistic regression models were used to determine the primary outcome while other results were analyzed using standard bivariate testing.

Results: Out of 158 fetuses with IUGR, 127 neonates met inclusion criteria (mean GA 30.3 ± 1.9 weeks, mean BW 1000 ± 313 grams). The majority of neonates were born via Cesarean section (97%) in the setting of maternal receipt of antenatal steroids (94%). In this cohort, 57% were female infants, 32% were Caucasian, 26% African American and 27% Hispanic. The rate of fetal demise was 4%, while postnatal mortality was 3%. There were 23 sets of twins, but only 11 sets included one infant with IUGR. In this group, 42% had evidence of AEDF in the UA, 33% REDF in the UA, and 25% with normal Dopplers. There was no significant association between abnormal Doppler patterns and the composite outcome but a trend towards severe IVH or PVL (P=0.06) (Table 1). In a logistic regression model, a higher birthweight was associated with a decreased risk of the composite outcome (OR 0.99, P=0.04) while plurality suggested a higher risk but was not significant (OR 3.2, P=0.06). Infants in group 3 required a significantly higher number of days of total parenteral nutrition, longer time to reach full enteral feeds (Table 2) and a significantly higher incidence of necrotizing enterocolitis or NEC (P=0.02) (Table 1).

Conclusions: In this cohort, a more severe Doppler pattern was associated with increased morbidities such as NEC and potentially increased risk of IVH or PVL. Long-term follow-up is needed in a larger cohort to determine neurodevelopmental outcomes.