Fetal evaluation in post-term pregnancy using vibroacoustic stimulation and amniotic fluid index versus modified biophysical profile [a comparative study]

ABSTRACT

The appropriate management of post-term pregnancy is controversial. Several methods of fetal surveillance are used to differentiate compromised from non-compromised fetuses. The study compares the modified fetal biophysical profile [FBP] with vibro-acoustic stimulation [VAS] and amniotic fluid index [AFI] in post-term pregnancy. Sixty cases of uncomplicated singleton post-term pregnancies [> 41 w] are enrolled in the study. The cases are randomly allocated into one of 2 groups for biweekly fetal surveillance. Group [I] Comprises 30 cases for whom VAS/AFI are performed. Group [II] Comprises 30 cases for whom modified FBP is performed. The specificity, positive predictive value and overall accuracy of VAS/AFI in predicting abnormal neo-natal outcome is higher than that of the FBP. Fetal BP is associated with higher incidence of false abnormal results and subsequent induction of labour. These abnormal results are attributable to BPP score 6, a poor predictor of perinatal outcome. This study indicates that VAS/AFI test in a better predictor of the development of intrapartum fetal distress in post-term pregnancy