Efficacy of antepartum fetal surveillance for stillbirth prevention

In 2019 the American College of Obstetricians and Gynecologists (ACOG) issued specific recommendations for performance of antepartum fetal surveillance (AFS) based on individual risk factors. As similar recommendations were already in place at our institution, we have evaluated the impact of AFS on stillbirth (SB) occurrence in a 5-year cohort.

Retrospective cohort study of all deliveries between 7/1/2013 and 6/30/2018. Excluded were multiples, anomalous fetuses or newborns, and deliveries before 32 0/7 weeks' gestation. AFS was conducted from 32 weeks with a modified biophysical profile, with a complete biophysical profile as back-up for non-reactive non-stress tests. All cases of SB were prospectively identified and individually reviewed to verify the presence of risk factors, the results of fetal testing if done, and calculate the interval between last fetal test and delivery. The electronic medical records during the study period were queried to identify women who underwent AFS and those who did not. Chi-square was used to compare the rates of SB between the two groups.

16,827 women fulfilled the study inclusion and exclusion criteria, 5711 (34%) had risk factors which prompted AFS; 37% had 2 or more risk factors. SB occurred in 1.8‰ of them (10/5711) (3 had 1 risk factor, 5 had 2, and 2 had 3 risk factors). Rates of SB at ≥32.0 weeks were similar between women who had AFS and those who did not (1.8 vs. 2.3‰, p = 0.51, OR = 0.75, 95%CI 0.36-1.55). The false-negative rate at <7 days of a reassuring AFS among compliant women was 1.4‰ (8/5711). Rates of preterm delivery were similar in the tested vs untested population (6.5 vs. 6.0%, p = 0.22).

Implementation of AFS in women with risk factors similar to those recommended by the ACOG may lower the risk of SB from 32 weeks to that of low-risk pregnancies.