Evaluation of Doppler indices (MCA & UA) and fetal outcomes: a retrospective case-control study in women with hypertensive disorders of pregnancy

Background Hypertensive disorders of pregnancy (HDP) is associated with an increased risk of adverse outcomes. The fetal middle cerebral artery (MCA) and umbilical artery (UA) blood flow detected by ultrasound are recommended to evaluate the oxygenation of the fetus. It is necessary to analyze the relationship between MCA & UA doppler indices or cerebroplacental ratio (CPR) and fetal outcomes and describe MCA and UA blood flow values across gestation. Methods Hospital-based retrospective case-control study during 2016 to 2020. 800 singleton pregnant women: 400 normotensive control, 219 gestational hypertension (GH), and 181 preeclampsia (PE)/eclampsia (EC). An analysis of the outcomes of mothers and neonates was performed. The fetal MCA and UA blood flow values across gestation were established, and MCA-resistance index (RI) and CPR were used to predict fetal distress and small for gestational age (SGA). Results In the normotensive control, GH and PE/EC groups, the mean gestational age (GA) was 38.9 +/- 1.2 weeks, 39.0 +/- 1.0 weeks, and 38.6 +/- 1.3 weeks respectively, and the mean birth weight (BW) was 3.195 +/- 0.387 kilograms, 3.198 +/- 0.428 kilograms, and 2.987 +/- 0.544 kilograms respectively. There were differences in GA, BW, fetal distress, SGA and intraventricular hemorrhage I-II between the hypertension group and normotensive control group (p < 0.05). The MCA-RI (sensitivity: 70.1%, specificity: 64.3%) and MCA-RI (sensitivity: 52.4%, specificity: 84.6%) were the best indices to predict fetal distress and SGA, respectively during GA of 35-40 weeks. Conclusions Fetal MCA blood flow values and CPR are of great benefit for obstetricians to evaluate the status of fetus evidentially in singleton pregnancy.

Automated summary

This study analyzed the relationship between fetal middle cerebral artery (MCA) and umbilical artery (UA) blood flow indices or cerebroplacental ratio (CPR) and fetal outcomes, and described MCA and UA blood flow values across gestation. The results showed that MCA-resistance index (RI) (sensitivity: 70.1%, specificity: 64.3%) was the best index to predict fetal distress, and MCA-RI (sensitivity: 52.4%, specificity: 84.6%) was the best index to predict small for gestational age (SGA) during gestational age of 35-40 weeks. These findings are important for obstetricians to evaluate the status of singleton pregnancies.