Serum macrophage stimulating protein α-chain and uterine artery Doppler ultrasound in the first trimester for the prediction of preeclampsia

To assess how effective macrophage stimulating protein α-chain (MSP-α) combined with uterine artery Doppler is in predicting preeclampsia in singleton pregnancies during 11-13⁺⁶ weeks of gestation. This prospective observational study included singleton pregnant women who attended antenatal care at King Chulalongkorn Memorial Hospital, Department of Obstetrics and Gynecology, Faculty of Medicine, Chulalongkorn University between December 2021 and April 2023, during 11-13⁺⁶ weeks of gestation. Serum MSP-α levels were collected and uterine artery Doppler ultrasound was performed. Pregnancy outcomes were recorded, and the predictive values of these tests were determined to predict preeclampsia. A total of 365 patients, with 21 cases of preeclampsia (5.8%), were analyzed. Serum MSP-α levels were higher in pregnant women who developed preeclampsia than those who did not (899.7 ± 550.1 ng/ml vs 642.5 ± 466.1 ng/ml, p = 0.016). The mean pulsatility index of the uterine artery and the presence of diastolic notching were not significantly different between the groups. As a cut-off value for predicting preeclampsia, using serum MSP-α levels higher than 1.0 multiple of median for gestational age, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 71.4%, 50.3%, 8.1%, and 96.7%, respectively. Additionally, when abnormal serum MSP-α levels were combined with a uterine artery Doppler pulsatility index above the 95th percentile and bilateral notching as predictive values for preeclampsia, the sensitivity was 85.7%, specificity was 18.3%, PPV was 6.0%, and NPV was 95.5%. Serum MSP-α alone at 11-13⁺⁶ weeks of gestation was effective in predicting preeclampsia. However, the use of serum MSP-α in combination with uterine artery Doppler increased sensitivity but reduced specificity for the prediction of preeclampsia.