Background: This study aimed to investigate the relationship between maternal predisposing factors with the level of maternal serum pregnancy-associated plasma protein A and free subunit human chorionic gonadotropin and nuchal translucency.
Materials and Methods: We performed a cross-sectional-analytical study on 762 pregnant women who referred to the Gene Azma Medical Genetics Laboratory in Isfahan for amniocentesis. All pregnant women at high risk of screening in the first trimester of pregnancy for trisomy 21 and other aneuploidy were referred to a gynecologist for amniotic fluid sampling (amniocentesis). Multiple of the means (MoM) of PAPPA ≤0.5, 0.5 ≥ MoM free β-hCG >2.5, and NT ≥3.5 mm were considered abnormal. We used Chi-square method and Mann–Whitney U-test to compare data qualitative and quantitative, respectively.
Results: In individuals with less pregnancies and deliveries, the value of abnormal NT was higher (P < 0.01, P < 0.001, respectively). On the other hand, the highest abnormal rate of NT was observed in pregnant women under 35 years (21, 84%, P < 0.012). In addition, abnormal levels of free β-hCG are more common in women < 35 years of age (186, 66.9%, P < 0.02) and female fetuses (171, 58.8%) (P < 0.006).
Conclusion: According to the results of this study, it can be said that considering the underlying factors of pregnant mothers in performing tests related to screening in the first trimester of pregnancy can lead to a reduction in false positive rates.