BACKGROUND AND PURPOSE:

• Boutin et al. (AJOG, 2021) estimated the rate of placenta-mediated pregnancy complications in nulliparous women with a positive first-trimester FMF preterm preeclampsia screening test

METHODS:

• Prospective cohort study
  • Secondary analysis of the Great Obstetrical Syndromes cohort study
• Participants
  • Nulliparous women
  • 11w0d to 13w6d
• Exposure
  • Positive or negative FMF algorithm test according to 2 risk cutoffs (1 in 70 and 1 in 100)
• Study design
  • FMF algorithm inputs (based on the ASPRE study): Maternal characteristics | Mean arterial blood pressure | Maternal serum biomarkers | Mean uterine artery pulsatility index
  • Certain maternal characteristics were not available, including family history of preeclampsia or SLE
• Primary outcomes
  • Test performance for preeclampsia, SGA of <10th percentile and <3rd percentile, and fetal death
  • Test performance for composite outcome of above complications
  • Test performance for severe composite outcome: Preterm PE, SGA of <3rd percentile, and intrauterine fetal death

RESULTS:

• 4575 participants
  • Estimated risk of preterm preeclampsia of ≥1 in 70: 10.8%
  • Risk of ≥1 in 100: 15.9%
• The test based on a risk cutoff of 1 in 70 could have correctly predicted the following, with a false positive rate of 10%
  • Preeclampsia: up to 27% of cases
  • Preterm preeclampsia: 55%
  • Small for gestational age: 18%
  • Severe small for gestational age: 24%
  • Fetal deaths: 37%
• The test based on a cutoff of 1 in 100 could have predicted correctly the following, with a false positive rate of 15%
  • Preeclampsia: up to 35% of cases
  • Preterm preeclampsia: 69%
  • Small for gestational age: 25%
  • Severe small for gestational age: 30%
  • Fetal deaths: 53%
• The positive predictive value of a screening test for preterm preeclampsia at a cutoff of ≥1 in 70
  • Preterm preeclampsia: 3%
  • Composite outcome: 32%
  • Severe composite outcome: 9%

CONCLUSION:

• Nulliparous women who test “screen positive” on the FMF’s preterm preeclampsia screening test are at a higher risk of both preterm preeclampsia and other placental-mediated pregnancy complications
• Approximately 1 in 10 women identified as at risk by the algorithm developed a placental-mediated complication

Learn More – Primary Sources:

Pregnancy outcomes in nulliparous women with positive first-trimester preterm preeclampsia screening test: the Great Obstetrical Syndromes cohort study

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