Prognostic components of the nonreactive nonstress test

Area of Science:

• Obstetrics and Gynecology
• Fetal Monitoring
• Perinatal Medicine

Background:

• Nonstress testing (NST) is a common method for assessing fetal well-being.
• Nonreactive NST results warrant further investigation due to potential associations with adverse perinatal outcomes.

Purpose of the Study:

• To retrospectively analyze nonreactive nonstress test tracings to identify components predictive of perinatal outcomes.
• To evaluate the significance of NST parameters in relation to subsequent contraction stress tests (CSTs) and fetal well-being.

Main Methods:

• Retrospective analysis of 102 nonreactive nonstress tests performed within one week of delivery.
• Comparison of NST components between fetuses delivered with positive and negative contraction stress test results.
• Analysis of NST parameters in growth-retarded fetuses versus those appropriate for gestational age.

Main Results:

• Nonreactive NSTs with fewer accelerations (>15 bpm or >20 seconds) and more nonreactive fetal movements were associated with positive CST results.
• Growth-retarded fetuses showed significantly fewer accelerations (>15 bpm or >20 seconds) compared to fetuses appropriate for gestational age, despite similar fetal movement counts.

Conclusions:

• Specific features of nonreactive nonstress tests, including reduced accelerations and increased nonreactive movements, are linked to adverse perinatal outcomes.
• NST findings, particularly concerning accelerations, are crucial for assessing fetal well-being, especially in growth-restricted fetuses.