Prediction of ischemic placental diseases during the first trimester combined test period: a retrospective cohort of low-risk pregnancies in search of the link between parity and disease.

To assess the predictive power of a multifactorial model established on maternal characteristics, placenta-associated plasma protein A (PAPPA), and the mean uterine artery pulsatility index (Ut A PI) levels for the development of ischemic placental diseases (IPD) during the first-trimester combined test (FTCT) period and to evaluate the strength of some generally accepted clinical risk factors. The studied data were obtained from a retrospective cohort of low-risk singleton pregnancies in the FTCT between 1 August 2016 and 1 December 2017. After routine 11-13-week examinations for FTCT, the Ut A PI was measured and stored electronically. The PAPPA multiple of median (MoM) was obtained as a routine component of aneuploidy screening. A sample of 2493 pregnancies with clearly documented outcomes was studied. Early-onset preeclampsia, late-onset preeclampsia and fetal growth restriction (FGR) were observed in 9 (0.36%), 27 (1.08%), and 41 (1.64%) cases, respectively. With optimum cut-off levels of 0.69 for PAPPA MoM and 2.05 for mean Ut A PI and a false positive rate of 4.9%, IPD cases could be predicted with 83.3% sensitivity and 73.7% specificity. Nulliparity, previous abortion in nulliparous women and first pregnancy from second marriage were not independent risk factors. Maternal age, an interval from the last delivery longer than 6 years, and body mass index were found to be independent risk factors. The IPD showed some common and distinct clinical, laboratory and Doppler findings during the FTCT and were predictable with the help of multifactorial analysis. Some widely accepted risk factors could be affected by various confounders. Because of the increased IPD frequencies, parous women with a time interval from the last delivery of 6 years or longer should be screened as a high-risk group for placental dysfunction-related diseases.