Prognostic role of umbilical artery Doppler velocimetry in growth-restricted fetuses

Abstract

Objective: To correlate umbilical artery Doppler velocimetry with perinatal outcome in a group of growth-restricted fetuses.Design: The study was a retrospective analysis of 578 singletonpregnancies with diagnosis of intrauterine growth restriction (IUGR), delivered in a single obstetric unit, at the Spedali Civili, Brescia, Italy, a university and teaching hospital with 3500 deliveriesa year and neonatal intensive care unit (NICU).Methods: During 1991-99 we studied 578 pregnancies with a diagnosis of IUGR referred for Doppler velocimetry. From this population, four subsetswere formed: normal umbilical artery pulsatility index (NUAPI; 334 fetuses); increased pulsatility index but with telediastolic flow (abnormal umbilical artery pulsatility index AUAPI; 137 fetuses); absentend-diastolic flow (AEDF; 70 fetuses); reverse telediastolic flow (RF; 37 fetuses). Fetal biometry, amniotic fluid and fetal-maternal Doppler velocimetry were evaluated in all patients, with biophysicalprofile and routine non-stress test, when indicated. The following outcomes were examined: mean gestational age at delivery, number of preterm deliveries (< 34 weeks), mean neonatal weight, Apgar scoreat 5 min < 7, prenatal and neonatal deaths (within the first 28 days of life), admission to the NICU and number of days spent after birth in hospital. Neonatal morbidity was analyzed, including respiratorydistress syndrome (RDS), intraventricular hemorrhage (IVH, grade 2-3), necrotizing enterocolitis (NEC) and retinopathy of prematurity. Long-term neurological follow-up is still ongoing and will not be presentedin this paper.Results: Out of 578 fetuses with IUGR, 547 were born alive. There were 26 neonatal deaths. The mean gestational age at delivery was 35.6 ± 4 weeks and mean birth weight1844 ± 612 g. There were 28 intrauterine deaths and three elective terminations of pregnancy. A total of 60 cases (11%) were complicated by RDS, 13 cases (2.4%) by retinopathy of prematurity, IVHwas present in nine cases (1.6%) and NEC in seven cases (1.3%). Total perinatal mortality was 9.8%; in the 26 cases of neonatal death, the mean week at delivery was 29.6 ± 4 with a mean weight of840 ± 425 g. Patients with NUAPI had a mean week at delivery of 37 ± 3, those with AUAPI delivered at 34 ± 3.2, those with AEDF delivered at 31 ± 3 and those with RF deliveredat 29 ± 2 weeks. In progressively worsening umbilical velocimetry, we observed an increase of incidence of low Apgar score. Days of admission to the NICU and incidence of perinatal mortality increasedwith the worsening of Doppler velocimetry.Conclusions: Our study underlines the existence of a strict correlation between umbilical Doppler velocimetry and an increased incidence of perinatalcomplications in IUGR fetuses.