Assistant Professor of Radiology, Department of Radiology, Poursina Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
Resident of Radiology, Reproductive Health Research Center, Student Research Committee, Guilan University of Medical Sciences, Rasht, Iran.
Assistant Professor of Obstetrics and Gynecology, Reproductive Health Research Center, Department of Obstetrics & Gynecology, Al-Zahra Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
Associate Professor, Department of Biostatistics, Social Determinants of Health Research Center, Guilan University of Medical Sciences, Rasht, Iran.
Background: The low level of pregnancy-associated plasma protein A (PAPP-A) has a relationship with unfavorable outcomes in neonates. This study aimed to evaluate the association between the thickness and size of the placenta in singleton pregnant women.
Materials and Methods: In this prospective cohort study, 102 women were investigated in 18-23 weeks and PAPP-A level at the gestational age in 11-14 weeks with a 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 an exposed group and others to a non-exposed group. Placental thickness and size were assessed during the second trimester by ultrasound examination and described as abnormal high thickness if the thickness was > 4 cm or more than 50% of the placental length and abnormally small size when the maximum length was < 10 cm. Then, placental thickness and size were compared between the two groups.
Results: PAPP-A levels of > 0.5 and ≤ 0.5 were recorded in 60 and 34 patients, respectively. 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 was 12 and 7 cases, respectively, in the other group (P = 0.023). The sensitivity and specificity of PAPP-A < 0.55 were 72.3 and 56% for abnormal placental thickness, respectively; the sensitivity and specificity of PAPP-A < 0.55 were 69.3 and 57.1%, respectively, in the assessment of abnormal placenta size.
Based on the results, the size and thicknesses of the placenta were abnormal in women with a low level of PAPP-A (≤ 0.5).