Small for gestational age preterm infants and relationship of abnormal umbilical artery Doppler blood flow to perinatal mortality and neurodevelopmental outcomes

Aim: To determine the outcomes of preterm small for gestational age (SGA) infants with abnormal umbilical artery (UA) Doppler studies.
Methods: A retrospective cohort study of SGA singleton infants delivered between 24 and 32 weeks gestation at King Edward Memorial Hospital, Perth, who had UA Doppler studies performed within seven days of birth. Main outcomes assessed were perinatal mortality and morbidity, and neurodevelopmental outcomes at ≥ 1 year of age. Outcomes were compared by normality of UA blood flow.
Results: There were 119 infants in the study: 49 (41%) had normal UA Doppler studies, 31 (26%) had an increased systolic–diastolic ratio ≥ 95th centile, 19 (16%) had absent end diastolic blood flow (AEDF) and 20 (17%) had reversed end-diastolic flow (REDF). Infants in the AEDF and REDF groups were delivered significantly more preterm ( P  = 0.006) and had lower birthweights ( P  < 0.001). Ninety four per cent (110 of 117) of live born infants survived. Neurodevelopmental follow-up at 12 months of age or more (median 24 months) was available on 87 of 108 (81%) of live children. Twenty-eight per cent (11 of 39) of fetuses who had had AEDF or REDF died or were classified with moderate or severe disability. There was no significant association between abnormality of UA blood flow, perinatal morbidity, perinatal mortality and neurodevelopmental disability after correction for gestational age.
Conclusion: Fetuses that are SGA with abnormal UA Doppler studies remain at significant risk of perinatal death, perinatal morbidity and long-term neurodevelopmental disability, associated with their increased risk of preterm birth.