Preterm nonstress testing: 10-beat compared with 15-beat criteria

Area of Science:

• Obstetrics and Gynecology
• Fetal Monitoring
• Perinatal Medicine

Background:

• Nonstress tests (NSTs) are used to assess fetal well-being.
• Interpretation criteria for NSTs, particularly in preterm pregnancies, require evaluation.
• The significance of different acceleration criteria in predicting perinatal outcomes needs clarification.

Purpose of the Study:

• To evaluate the relationship between various nonstress test (NST) acceleration criteria and perinatal outcomes.
• To compare the predictive value of 10-beat versus 15-beat criteria for NST interpretation in early gestation.

Main Methods:

• Retrospective analysis of 751 nonstress tests (NSTs) from 488 women at 32 weeks gestation or earlier.
• NSTs classified as reactive by 10-beat or 15-beat criteria, or nonreactive.
• Analysis of perinatal outcomes including death, resuscitation, Apgar scores, and specific morbidities.
• Logistic regression used to adjust for gestational age and birth weight.

Main Results:

• No significant association found between NST criteria (10-beat, 15-beat, decelerations) and perinatal outcomes after adjusting for gestational age and birth weight.
• Nonreactivity on NST was associated with perinatal death (OR 6.1).
• In women with repeated NSTs, varying reactivity patterns were common and not significantly linked to outcomes.

Conclusions:

• Gestational age at delivery is a more significant factor than NST interpretation criteria in preterm pregnancies.
• The 10-beat and 15-beat criteria for NST interpretation demonstrate similar predictive value for outcomes.
• Fetal reactivity patterns on repeated NSTs in preterm fetuses do not consistently predict perinatal outcomes.