Association of different serum PAPP A levels, in first trimester, with adverse pregnancy outcomes: a retrospective study

Background The first trimester screening test for aneuploidy, including pregnancy-associated plasma protein A (PAPP A), has been used in clinical practice for over forty years. Studies have shown that in addition to screening for aneuploidy, PAPP A is also a potential early marker for adverse pregnancy outcomes. The aim of this study is to investigate different PAPP A levels and analyze the association with pregnancy outcomes. Methods A retrospective cohort study was designed for singleton pregnancies that underwent first trimester screening. A PAPP A value above 3.73 MoM (99th percentile) was defined as an extremely high PAPP A group. A low group was defined as PAPP A below 0.41 MoM (< 5th percentile), normal group defined as 0.42–2.50 MoM (between the 5th and 95th percentile) and high group defined as PAPP A value between 2.51 and 3.73 MoM (between the 95th and 99th percentile). Out of 16646 patients 55 (0.03%) had a PAPP A MoM level > 99th percentile and 43 of them were eligible for the study. The participants of the other groups matched the date of the screening test of the extremely high group participants. Results Fetal growth restriction, Gestational diabetes mellitus, birth weight, cesarean section rate and admission to Neonatal intensive care unit were significant for the low PAPP A group. Oligohydroamnios, polihydroamnios, preterm labor, preterm premature rupture of membranes, small for gestational age, gestational hypertension, preeclampsia, macrosomia, intrauterine demise after 22 weeks' gestation and placental abruption were not significant for the groups (p > 0.05). Conclusions PAPP A is produced by placental tissue and has the potential to be an indirect diagnostic tool for placental function and the prediction for adverse pregnancy outcomes. Clinicians and so patients feel distress if the screening test result report altered PAPP A levels. Low PAPP A concentrations appear to be associated with an adverse pregnancy outcome and gestational diabetes mellitus but high or extremely high PAPP A levels have no effect on obstetric and neonatal outcomes.