A Prospective Study of Cerebroplacental Ratio: A Marker of Impaired Fetal Growth Velocity And Adverse Outcome

Abstract

ABSTRACT Background: Antenatal detection of Fetal Growth Restriction (FGR) and its antepatum survelliance is initially done by different methods one among them is the Doppler studies by using Middle Cerebral Artery (MCA), Umbilical Artery (UA) Indices .The umbilical artery assesses the resistance to blood perfusion of the fetoplacental which detects early maternal or placental conditions obliterating muscular arteries. Result in a progressive decrease in end-diastolic flow in the umbilical artery Doppler waveform until absent and then reversed flow which represents an advanced stage of placental compromise, commonly associated with severe IUGR and oligohydramnios. It is also noted as Middle cerebral artery peak systolic velocity may be a better predictor of Intra Uterine Growth Restriction (IUGR). Here, blood flow redistribution known as the brain-sparing reflex, is characterized by increased end-diastolic flow velocity (reflected by a low PI) in the middle cerebral artery. Current challenges in the clinical management of IUGR include accurate diagnosis of the truly growth-restricted fetus, selection of appropriate fetal surveillance is been assessed with the cerebroplacental ratio, defined as middle cerebral artery PI/umbilical artery PI. The cerebroplacental ratio has been proposed as a marker of failure of growth potential. Low cerebroplacental ratio, regardless of the fetal size, is independently associated with the need for operative delivery for fetal compromise and adverse fetal outcome, as CPR proves to be more reliable for assessment for fetal well being. Objective: The main aim was to evaluate the cerebroplacental ratio at term as a marker of reduced fetal growth rate and to investigate the relationship between low cerebroplacental ratio at term with reduced fetal growth velocity and adverse perinatal outcome. Design: It was a Prospective study of 200 singleton pregnancies in a tertiary care hospital. The abdominal circumference was measured between 20-24 weeks’ gestation, and both abdominal circumference and fetal Dopplers to measure Middle Cerebral Artery and Umbilical Artery indices were recorded at or beyond 35 weeks of gestation. Abdominal circumference values were converted into Z scores and centiles of birth weight and fetal Doppler parameters, adjusting for gestational age. Abdominal circumference growth velocity was quantified using the difference in abdominal circumference Z score, at or beyond 35 weeks compared with the scan between 20-24 weeks. The logistic regression analyses were performed to investigate the association between low cerebroplacental ratio, low abdominal circumference, growth velocity and to identify and adjust for potential confounders. Results: The study included 200 pregnancies in which we found that total number of operative deliveries were about 71 cases (48%). Out of 75 cases Low CPR 27 cases (36%) underwent operative deliveries (p=0.909), of 125 cases Normal CPR 44cases (35.2%) underwent operative deliveries. Hence, CPR remained not significantly associated with the risk of operative delivery for fetal compromise (p= 0.023). Conclusion: Among the 200 cases of study population 75 cases (37.5%) and 125 cases (62.5%)were having low and normal Cerebro Placental Ratio (CPR) .The study reveals higher incidence of low Abdominal Circumference (AC) and Small for Gestational Age (SGA) babies among low CPR group compared to normal CPR women. The present study showed no difference in the incidence of Cesearean section delivery for fetal compromise ,low APGAR Score at 5 minutes (<7) and admission to Neonatal Intensive Care Unit among the low CPR and normal CPR group women. However, multicentric studies with large sample size are required to further investigate the usefulness of CPR in predicting adverse maternal and perinatal outcome.