Comparative Study of Pregnancy-associated Plasma Protein A in Women with Threatened Miscarriage and Normal Pregnant Women at a Tertiary Referral Center

Abstract

BACKGROUND: Miscarriage is a common complication of pregnancy. Several pregnancy biomarkers have been used to predict spontaneous miscarriage, but these have shown conflicting results. A biomarker such as pregnancy-associated plasma protein A (PAPP-A) may likely prognosticate the clinical progress of pregnancy in early pregnancy assessment. MATERIALS AND METHODS: It was a prospective cohort study involving 98 pregnant women with threatened miscarriage and 98 pregnant women with normal ongoing pregnancy, recruited between 6 and 20 weeks of gestation. Blood samples were collected at enrollment from the participants to assay PAPP-A serum levels, and they were followed up till 28 weeks of gestation to document the outcome (failed or continued pregnancy). Statistical analysis was performed using the Stata version 16 (STATA Corp., USA). RESULTS: Multiple of the median (MoM) of serum PAPP-A levels was lower among the threatened miscarriage group compared to the women with normal ongoing pregnancy (0.98 MoM vs. 1.06 MoM, P < 0.0001). Furthermore, median plasma PAPP-A MoM was significantly lower among women with threatened miscarriage who had spontaneous miscarriage compared with those with ongoing pregnancy (0.35 [0.15-0.60] vs. 1.02 [0.89-1.29]; P < 0.0001). At the optimal cutoff of ≤0.63 MoM, serum PAPP-A level significantly predicted the occurrence of failed pregnancy with sensitivity and specificity of 77.3% and 93.4%, respectively. CONCLUSION: A low maternal serum PAPP-A level was significantly associated with the occurrence of threatened miscarriage and failed pregnancy among pregnant Nigerian women. Serum PAPP-A level of <0.63 MoM significantly predicted the occurrence of failed pregnancy with sensitivity and specificity of 77.3% and 93.4%, respectively. Larger prospective multicenter studies are needed to further investigate the clinical usefulness of maternal serum PAPP-A level in evaluating women with threatened miscarriage in our environment.