Mid-trimester placentation assessment in high-risk pregnancies using maternal serum screening and uterine artery Doppler

Objective. To determine the value of uterine artery velocimetry and mid-trimester maternal serum AFP/hCG measurements in predicting pregnancy complications in a high-risk group of pregnant patients. Methods. Eighty-eight patients with chronic hypertension, previous preeclampsia, and thrombophilia were included. Maternal serum AFP/hCG was examined between 15-16 weeks gestation. Levels > 3 multiple of median (MoM) for hCG and > 2 MoM for AFP were considered abnormal. Color Doppler ultrasound was performed at 23-24 weeks gestation. Diastolic notching and pulsatilty index (PI) above the 95th percentile were considered abnormal. Results. Thirty-three patients had abnormal uterine artery waveform: 8 patients had abnormal maternal serum hCG and 5 had abnormal maternal serum AFP. Bilateral abnormal uterine artery waveform was associated with pregnancies complicated by lower gestational age at delivery (p = 0.05) and birth weight (p < 0.01), higher rates of preeclampsia (p = 0.006), SGA (p = 0.0001), preterm delivery (p = 0.0001), and cesarean section rate (p < 0.0001) in comparison to patients with normal uterine artery Doppler. Pregnant women with elevated hCG had higher rates of preeclampsia (p = 0.006); preterm delivery (p = 0.005) and SGA (P = 0.03) and, lower birth weight (p = 0.001). No significant differences were noted for clinical outcomes according to AFP data. Conclusions. Abnormal uterine artery waveform is superior to maternal serum hCG for identification of placental pathology leading to preterm delivery, low birth weight, and preeclampsia in high-risk pregnant patients.