Reactive nonstress test despite severe congenital brain damage. What does the test measure?

BACKGROUND

Antenatal testing with the nonstress test is common in the evaluation of high-risk pregnancies. A reactive test gives the clinician reassurance of fetal well-being.

CASE: A 19-year-old woman, gravida 1, para 0, delivered an infant with holoprosencephaly and multiple facial and limb abnormalities at 38 weeks' gestation. The fetal heart tracing was reassuring despite the infant's compromised neurologic status.

CONCLUSION

The nonstress test is dependent only upon the fetal brainstem, and it predicts oxygenation at that site rather than normality of the entire central nervous system. This limitation of the nonstress test must be remembered when performing antenatal testing.