An abnormal cerebroplacental ratio (CPR) is predictive of early childhood delayed neurodevelopment in the setting of fetal growth restriction

Background: Fetal growth restriction accounts for a significant proportion of perinatal morbidity and death. The cerebroplacental ratio is gaining much interest as a useful tool in differentiating the "at-risk" fetus in both fetal growth restriction and appropriate-for-gestational-age pregnancies. The Prospective Observational Trial to Optimize Pediatric Health in Fetal Growth Restriction group has demonstrated previously that the presence of this "brain-sparing" effect is associated significantly with adverse perinatal outcomes in the fetal growth restriction cohort. However, data about neurodevelopment in children from pregnancies that are complicated by fetal growth restriction are sparse and conflicting.

Objective: The aim of the Prospective Observational Trial to Optimize Pediatric Health in Fetal Growth Restriction NeuroDevelopmental Assessment Study was to determine whether children born after fetal growth-restricted pregnancies are at additional risk of adverse early childhood developmental outcomes compared with children born small for gestational age. The objective of this secondary analysis was to describe the role of cerebroplacental ratio in the prediction of adverse early childhood neurodevelopmental outcome.

Study design: Participants were recruited prospectively from the Perinatal Ireland multicenter observational Prospective Observational Trial to Optimize Pediatric Health in Fetal Growth Restriction study cohort. Fetal growth restriction was defined as birthweight <10th percentile with abnormal antenatal umbilical artery Doppler indices. Small for gestational age was defined similarly in the absence of abnormal Doppler indices. Cerebroplacental ratio was calculated with the pulsatility indices of the middle cerebral artery and divided by umbilical artery with an abnormal value <1. Children (n=375) were assessed at 3 years with the use of the Ages and Stages Questionnaire and the Bayley Scales of Infant and Toddler Development, 3rd edition. Small-for-gestational-age pregnancies with normal Doppler indices were compared with (1) fetal growth-restricted cases with abnormal umbilical artery Doppler and normal cerebroplacental ratio or (2) fetal growth restriction cases with both abnormal umbilical artery and cerebroplacental ratio. Statistical analysis was performed with statistical software via 2-sample t-test with Bonferroni adjustment, and a probability value of .00625 was considered significant.

Results: Assessments were performed on 198 small-for-gestational-age children, 136 fetal growth-restricted children with abnormal umbilical artery Doppler images and normal cerebroplacental ratio, and 41 fetal growth-restricted children with both abnormal umbilical artery Doppler and cerebroplacental ratio. At 3 years of age, although there were no differences in head circumference, children who also had an abnormal cerebroplacental ratio had persistently shorter stature (P=.005) and lower weight (P=.18). Children from fetal growth restriction-affected pregnancies demonstrated poorer neurodevelopmental outcome than their small-for-gestational-age counterparts. Fetal growth-restricted pregnancies with an abnormal cerebroplacental ratio had significantly poorer neurologic outcome at 3 years of age across all measured variables.

Conclusion: We have demonstrated that growth-restricted pregnancies with a cerebroplacental ratio <1 have a significantly increased risk of delayed neurodevelopment at 3 years of age when compared with pregnancies with abnormal umbilical artery Doppler evidence alone. This study further substantiates the benefit of routine assessment of cerebroplacental ratio in fetal growth-restricted pregnancies and for counseling parents regarding the long-term outcome of affected infants.