1017: Third trimester ultrasound in low-risk pregnancies and perinatal death: A systematic review and meta-analysis

Abstract

To determine if third trimester ultrasounds in low-risk pregnancies decrease the rate of perinatal death compared to routine fundal height. Systematic review and meta-analysis of randomized control trials (RCTs) published prior to June 2019 performed on singleton, non-anomalous, low-risk pregnancies. Participants were randomized to either a third trimester ultrasound (US) or routine care by fundal height (FH). Databases used were OVID, PubMed, SCOPUS, ClinicalTrials.gov and Cochrane Central Register of Controlled Trials. Exclusion criteria were multiple gestations, maternal medical complications, cerclage, and known abnormal amniotic fluid or fetal growth prior to randomization. The primary outcome was the rate of perinatal death, irrespective of those caused by anomalies diagnosed after randomization. The secondary outcomes were rates of stillbirth, neonatal death, fetal growth restriction (FGR; EFW < 10th %ile), suspected large for gestational age (LGA; EFW >90th %ile), polyhydramnios, oligohydramnios, and rates of cesarean section (CD) and induction of labor (IOL). Six RCTs with a total of 10,563 participants (5255 US group vs 5308 FH group) were included. The total rate of perinatal death was similar between the groups, 27/4256 (0.6%) vs 19/4308 (0.4%) RR 1.4 (95% CI 0.79-2.56). There was no difference in the rates of stillbirth and neonatal deaths between ultrasound and fundal height (Table 1). The rates of FGR was higher in the US group, 485/3479 (14%) vs 224/3523 (6%) RR 2.2 (95% CI 1.9 – 2.6) as well as the rate of suspected LGA, 1060/3513 (30%) vs 375/3558 (11%) RR 2.8 (95% CI 2.6 – 3.2). Polyhydramnios was also significantly higher in the US group vs FH, 18/323 (5%) vs 4/322 (1%) RR 3.9 (95% CI 1.4 – 11). The rates of oligohydramnios and CD were similar between the groups. The rate of IOL for suspected fetal compromise was higher in the US group vs FH, 89/4509 (2%) vs 37/4555 (1%) RR 2.4 (95% CI 1.6 – 3.5). Third trimester ultrasounds do not decrease the rates of perinatal death compared to routine fundal height in low-risk pregnancies.View Large Image Figure ViewerDownload Hi-res image Download (PPT)