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

Abstract

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.