Role of non- stress test, amniotic fluid index, fetal middle cerebral, umbilical and renal artery Doppler indices in evaluation of post-term pregnancy

Abstract EN

Objective : In recent years, serial fetal monitoring are used to assess fetal wellbeing in women with unfavorable cervix up to 42 weeks’ gestation.

This study was performed to evaluate the accuracy of NST, AFI, fetal cerebral / umbilical and cerebral / renal pulsatility index (PI) and resistance index (RI) in predicting fetal outcome in post-term pregnancies in order to find out the best timing for intervention.

Patients and Methods : This prospective observational study comprised 60 pregnant women recruited according to the inclusion criteria from the outpatient antenatal care clinic at Al-Zahraa University Hospital.

After taking their consent, the patients were classified into 3 groups according to their gestational age.

Serial fetal surveillance tests and fetal Doppler indices were followed until spontaneous delivery or induction of labor.

Data collected are statistically correlated to delivery and perinatal outcomes.

Results : By comparing the results of fetal surveillance tests among the 3 groups of the study, a statistically significant difference was found in FKC (P=0.01), AFI (P=0.03) and MBFP (P=0.02).By combining NST and AFI in the so-called MBPP, the predictive values were: sensitivity 89%, specificity 84%, PPV 67%, NPV 95% and total diagnostic accuracy of 78%.

It was also found that abnormal (or less than 1.0) MCA / RA PI and abnormal MCA / UA PI were better indices in predicting adverse perinatal outcomes than MCA, RA and UA individual PI with statistically significant differences among the 3 groups.

Conclusions: Fetal Doppler indices, especially MCA, UA and RA should be part of routine follow up of post-term pregnancies with oligohydramnios.