The Nonstress Test

The predictive value of a nonstress test taken 24 h before delivery in high-risk pregnancies

OBJECTIVES

A series of 180 cases of high risk pregnancies were studied in order to assess if a nonstress test taken 24 h before delivery is of any prognostic significance.

METHODS

To assess the predictability of the NST (reactive or nonreactive) in terms of fetal outcome, the following variables were taken into consideration: fetal distress during labor, low Apgar score (< 7) and perinatal mortality rate.

RESULTS

A reactive test was found to be a good predictor of the healthy fetus (negative predictive value = 91.2%). Also, specificity of the test was found to be 85.4%.

CONCLUSIONS

The nonreactive test could identify a population at risk but it was not helpful as a 'stand alone' modality in decision making, because of the low sensitivity and positive predictive value rates (40.9% and 28.1%, respectively).

Obstetrical management of patients with diabetes in pregnancy

The management of the woman with diabetes diagnosed before the onset of pregnancy, or who develops it during pregnancy, requires a team approach involving the woman and her partner, the diabetes nurse educator, the dietitian, the endocrinologist, the obstetrician, the ultrasonologist and the paediatrician. It should start before pregnancy so that normoglycaemia is achieved before conception and maintained throughout gestation and labour. Fetoplacental surveillance commences with an early ultrasound to confirm fetal viability, repeated around 20 weeks to exclude major fetal malformations and then later in the third trimester to monitor fetal growth. CTG and biophysical profile assessment are major adjuncts to ensuring fetal well-being. The pregnancy should be allowed to go to full term when maternal blood glucose control has been satisfactory, fetal growth is within the normal range and other obstetrical complications, e.g. pre-eclampsia, are absent. Such an approach will ensure that the caesarean section rate can be minimized. During labour, the progress of labour and fetal well-being should be closely monitored. The woman who has microvascular complications of her diabetes (including proliferative retinopathy and nephropathy) requires even closer surveillance and premature delivery is more likely to be needed. The principles of management of the woman who develops gestational diabetes are similar, with even greater emphasis being placed on not inducing labour before full term unless complications dictate otherwise.