Middle cerebral artery to uterine artery pulsatility index ratios in pregnancy with fetal growth restriction regarding negative perinatal outcomes

Doppler indexes in fetal growth restriction

Abstract

Background/Aim: Fetal growth restriction (FGR) causes a high risk of perinatal morbidity and mortality, and the timing of the correct delivery time decision remains controversial. Cerebroplacental ratio (CPR), umbilical artery, uterine artery (UA) and middle cerebral artery (MCA) Doppler studies are used to predict adverse perinatal outcomes in FGR. However, since there is insufficient reliability for each separately and together, the search for new methods continues. This retrospective study was conducted to determine the degree of neonatal morbidity in fetuses suspected of having FGR by evaluating the MCA to UA pulsatility index (PI) ratios together with frequently used Doppler examinations.

Methods: This was a retrospective cohort study conducted in a single-center hospital with the approval of the Medical Institutional Ethics Committee. A total of 424 pregnant women admitted to a tertiary hospital and diagnosed with FGR between July 2020 and December 2021 who were informed and approved were included in the study. Gestational age was confirmed by first trimester sonographic measurements of pregnancy. All pregnant women were examined by Doppler USG and umbilical artery, mean UA, fetal MCA, ductus venosus, CPR (MCA/umbilical artery pulsatility index ratio) and cerebrouterine ratio (MCA/UA) PI values were measured. Negative perinatal outcomes were recorded as blood gas level of the newborn at 7.2 and below, Apgar score of 7 and below at the fifth minute, and needing neonatal intensive care (NICU). Adverse perinatal and postnatal outcomes were recorded and compared with Doppler findings. If there were no signs of a negative perinatal outcome, it was considered a positive outcome. If at least one of the symptoms of adverse perinatal outcomes was present, it was considered a negative outcome

Results: Decreased CPR and decreased MCA to UA PI were significantly and positively associated with an increased likelihood of exhibiting negative perinatal outcomes in pregnancies with FGR (P < 0.001, P < 0.001, respectively). The receiver operating characteristic (ROC) curve analysis showed that the optimal cut-off value for MCA to uterine artery PI was 1.41 to predict FGR with 57.37% sensitivity and 62.50% specificity (AUC: 0.629; 95% CI: 0.581–0.675). When the CPR cut-off value was taken as 1.2069, the sensitivity was 42.86% and the specificity 83.93% in predicting negative perinatal outcomes in CPR values below this value (P < 0.001).

Conclusion: CPR is the most successful criterion in distinguishing between positive and negative perinatal outcomes. It has been demonstrated that the MCA to uterine artery PI ratio values after CPR can also be used for this distinction. MCA to UA PI ratio sensitivity was higher than CPR and umbilical artery. This situation shows that MCA to uterine artery PI ratio (alone or when evaluated together with PPV and NPV ratios) is a criterion that can be added to other Doppler examinations in predicting negative perinatal outcomes.