Measurement of Cerebro-Placental Doppler Ratio and Amniotic Fluid Index as a Predictor of Perinatal Outcome in Prolonged Pregnancy

Background: The terms post-term, prolonged, postdates and post mature are often loosely used interchangeably to signifypregnancies that have exceeded a duration considered to be the upper limit of normal.Objective: The aim of this work was to study the role of Doppler velocimetry of the umbilical and middle cerebral arteriesrepresented by the cerebroplacental ratio and amniotic fluid volume in the prediction of adverse fetal outcome in post-termpregnancies.Materials and Methods: This is a prospective case control study conducted at Ain-Shams University Teaching Hospitalfor Obstetrics and Gynecology, Egypt. The study included 50 pregnant patients who were divided into two groups; group1included 25 pregnant ladies with gestational age of 41 weeks attending the casuality department in labour or in prodromaof labor. while, group 2 included 25 pregnant ladies with gestational age of 41 weeks not in labor and reaching thehospital for ANC, who were selected for termination based on the biophysical profile and poor Doppler indices or CTGchanges. All patients were submitted to antenatal fetal surveillance tests including modified biophysical profile (MBPP)which consists of the non-stress test (NST), amniotic fluid index (AFI), and color Doppler velocimetry of fetoplacentaland fetal vessels including MCA PI, UA PI, and CPR. The accuracy of cerebroplacental ratios (the middle cerebral arteryPI divided by the umbilical artery PI) and amniotic fluid volume as a means of predicting intrauterine fetal distress andadverse perinatal outcome in post-term pregnancies.Results: Cerebroplacental ratio showed the highest sensitivity (95%) in comparison with other parameters, so it is a goodtest to reassure the obstetricians of the fetal well being. Prominent changes in AFI (i.e. 5.0 cm. Asignificant association with FHR decelerations and presence of meconium is proved to exist when AFI is <5.0 cm.Conclusion: The addition of cerebral/umbilical ratios to antenatal surveillance protocols is expected to improve the perinataloutcome. It should be tried in the various high risk pregnancies whenever uteroplacental insufficiency is suspected.