摘要：Background: The low level of pregnancy-associated plasma protein A (PAPP-A) has relationship with unfavorable outcomes in neonates. We aimed to evaluate the association between thickness and size of placenta in singleton pregnant women. Materials and Methods: In this prospective cohort study, we investigated 102 women in 18-23 weeks and PAPP-A level at gestational age in 11 to 14 weeks with singleton pregnancy who referred to Al-Zahra Hospital, Rasht, Iran, between 2017 and 2018. Serum PAPP-A of pregnant women was measured in the first trimester of pregnancy. Patients who had PAPP-A ≤0.5 Multiple of the Median (MOM (were dedicated to exposed group and others to non-exposed group. Placental thickness and size were assessed during second trimester by ultrasound examination and described as abnormal high thickness if the thickness was > 4 cm or more than 50% of placental length and abnormally small size when the maximum length was 0.5 and 34 patients had PAPP-A ≤0.5. Women with low levels of PAPP-A in the first trimester had an increased incidence of abnormal placental thickness in 13 cases, and small placental size in 7 cases, whereas this number in another group was 12 and 7 cases, respectively (P=0.023). The sensitivity and specificity of PAPP-A Conclusion Based on the results, the size and thicknesses of placenta in women with a low level of PAPP-A (≤0.5) were abnormal.
