Antenatal cardiotocography: experience in a Nigerian tertiary hospital

To compare selected perinatal characteristics between infants of mothers with reactive and non-reactive antenatal cardiotocography (non-stress test) results.

The medical records of all women who delivered within one week of a non-stress test were retrieved. The indication, test result, gestational age at delivery, Apgar score at 5 minutes, perinatal complications and neonatal ward admission were documented.

One hundred and twelve women met study criteria among whom 51 tests were reactive and 61 were non-reactive. Post-datism, intra-uterine growth restriction, hypertensive disorders of pregnancy, and premature rupture of membranes were the commonest indications for the test. Post-datism was more commonly associated with a non-reactive test result. Women with non-reactive tests were almost twice as likely to be delivered by emergency Caesarean section, compared with women with reactive tests; although the test result did not significantly influence the mode of delivery. A non-reactive test was significantly associated with a higher perinatal mortality (p = 0.04). Although the reactive test was associated with a three-fold reduction in the incidence of low Apgar scores compared with the non-reactive test, this difference was not statistically significant (p = 0.18). A non-reactive test was significantly associated with small for gestational age infants (p = 0.01).

Non-reactive non-stress test may be associated with higher perinatal mortality. When appropriately utilised, the test is a valuable tool for early detection of foetal compromise. Antenatal cardiotocography has a place in obstetric practice in low-resource settings for improving perinatal care.