Nonstress testing at ≤32.0 weeks' gestation: a randomized trial comparing different assessment criteria

Objective Comparison of time and outcomes of National Institutes of Child Health and Human Development defined fetal heart rate acceleration criteria at ≤32 weeks (≥10 beats/min, ≥10 seconds) compared with standard criteria (≥15 beats/min, ≥15 seconds). Study Design Singleton high-risk pregnancies that were referred for nonstress testing at ≤32 weeks' gestation were randomly assigned to 15 × 15 or 10 × 10 criteria. Data included nonstress test information, maternal data, and outcomes. Results One hundred forty-three women were randomly assigned to 15 × 15 (n = 71) or 10 × 10 (n = 72). The groups were similar in maternal and pregnancy characteristics. Median time to reactive nonstress testing was shorter in the 10 × 10 group (37.3 minutes) than the 15 × 15 group (41.3 minutes; P = .04). There were no serious adverse events. Conclusion The time to attain a reactive nonstress testing at ≤32 weeks' gestation was 4 minutes shorter when the 10 × 10 criteria were used. There were no adverse events related to use of 10 × 10 nonstress testing criteria.