Objective: To assess the performance of screening for preeclampsia and intrauterine growth restriction by combining second trimester maternal serum screening and uterine Doppler ultrasound.
Methods: A cohort of 2,615 women underwent both maternal serum screening (using human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP)), and second trimester uterine artery Doppler. The sensitivity, specificity and predictive value of different combinations of both tests were compared.
Results: The mean values for hCG and AFP were significantly higher in women with subsequent preeclampsia (p < 0.0003 and p < 0.03, respectively). Taking into account obstetrical history, hCG and AFP levels, notching on uterine artery Doppler and parity, the adjusted odds ratios were significantly higher for a high level of hCG for preeclampsia, intrauterine growth restriction (IUGR) and pregnancy-induced hypertension. AFP level >1.5 MoM (multiples of the median) was significantly correlated with subsequent IUGR. The presence of a uterine notch was associated with a significantly higher risk of both preeclampsia and IUGR. The combination of an elevated serum level and the presence of a uterine notch had a positive predictive value (PPV) for preeclampsia of 25 and 21% for hCG and AFP, respectively. The combination of a bilateral notch with a low level of hCG or a high level of AFP had a PPV for IUGR of 50 and 43%, respectively. The sensitivity of the different tests ranged from 2 to 40%.
Conclusion: The combination of serum markers and abnormal uterine Doppler ultrasound improves the identification of women at risk for subsequent pregnancy complications. These results should encourage care providers to perform a uterine Doppler ultrasound when serum markers are abnormal. However, the sensitivity of these tests is too low to provide an efficient generalized screening.