First trimester screening for preeclampsia

Aspirin therapy from the first trimester of pregnancy may benefit women at high risk for preeclampsia. We review publications from the past year that examine first-trimester screening studies for preeclampsia.

For a false positive rate of 5%, first-trimester uterine artery Doppler studies will detect 50-65% of women who will develop severe preeclampsia (i.e. needing delivery before 35 weeks). Measurement of placental volume with three-dimensional ultrasound at 11-14 weeks detected 20% for a false positive rate of 10% in one study and further evaluation of this technique is needed. Maternal serum placental growth factor, vascular endothelial growth factor and soluble fms-like tyrosine kinase-1 have shown initial promise, but recent studies have shown no improvement in screening compared with using uterine artery Doppler alone. Placental protein 13 is the most promising serum marker and in combination with uterine Doppler may predict up to 90% of cases of severe preeclampsia for a false positive rate of 9%.

First-trimester uterine artery Doppler can identify over half of women who will develop preeclampsia. Detection rates may be increased by a combination of uterine artery Doppler with first-trimester maternal serum markers, especially placental protein 13. Such high-risk women may be the most likely to benefit from pharmacological intervention in future trials.