BACKGROUND AND PURPOSE:

• Recent studies indicate that predictive models can be used to identify women at risk for preeclampsia
• Aspirin appears to prevent preeclampsia and can be integrated into screening programs
• Sonek et al. (AJOG, 2017) determined the feasibility of first trimester screening for preeclampsia, including maternal characteristics, medical history, biomarkers, and placental volume

METHODS:

• Prospective observational nonintervention cohort study
• Inclusion: Patients who presented for an ultrasound examination between 11w0d-13w6d weeks’ gestation
• Risk of preeclampsia was calculated based on maternal characteristics, mean maternal arterial blood pressure at intake (MAP) maternal biomarkers, and estimated placental volume
• Ultrasound measurements included
  • Transabdominal Doppler measurement of the uterine artery pulsatility index (UtA-PI)
  • Estimated placental volume (EPV), using maximal width, height and thickness measurements
• Serum Biomarkers: (PAPP)-A, placental growth factor (PlGF), and maternal serum alpha-fetoprotein (MSAFP)
• Primary outome: preeclampsia with subsequent delivery either early (<34 weeks’ gestation) or late (≥34 weeks’ gestation)

RESULTS:

• 1068 patients were analyzed
  • 4.3% developed preeclampsia: 1.22% with early delivery <34 weeks, and 3.09% with delivery ≥34 weeks
• Using maternal characteristics, serum biomarkers and UtA-PI, the detection rate of early-onset preeclampsia was 85% with a 5% false positive rate
• With the same protocol, the detection rates for preeclampsia with delivery <37 weeks were 52% (5% false positive rate) and 60% (10% false-positive rate)
• Based on maternal characteristics, the detection rates for late-onset preeclampsia ≥34 weeks were 15% (5% false positive rate) and 48% (10% false positive rate), while for preeclampsia at ≥37 weeks’ gestation the detection rates were 24% and 43%, respectively
• The addition of biomarkers did not improve detection rates for late-onset preeclampsia and preeclampsia with delivery at >37 weeks’ gestation

CONCLUSION:

• Screening for preeclampsia at 11w0d-13w6d gestation using maternal characteristics and biomarkers is associated with a high detection rate for a low false-positive rate
  • MSAFP contributed to detection
• Screening for late-onset preeclampsia screening yields poorer results
• The addition of placental volume and mean arterial pressure was of limited benefit, however, and may be due to small sample size
  • MAP and PlGF have been shown to helpful in other studies and EPV (which tended to ward being smaller in this study) may still be shown to be of benefit in larger data sets
• This study was undertaken in the US, where testing is less centralized and ethnic and medical histories may differ from the UK
• The authors conclude that based on results which are consistent with previous studies such as the ASPRE trial, a first trimester screening program can detect those at risk of early onset preeclampsia

Learn More – Primary Sources:

First-trimester screening for early and late preeclampsia using maternal characteristics, biomarkers, and estimated placental volume

Related ObG Topics:

Aspirin Treatment for Women at Risk for Preeclampsia – ACOG and USPSTF Recommendations  

ASPRE Trial: A Combined Risk Algorithm and Use of Aspirin to Prevent Preterm Preeclampsia

Does Carrying a Fetus with a Congenital Heart Defect Increase Preeclampsia Risk?

Are Vitamin D Levels Linked to Preeclampsia and Preterm Birth?