زایمان زودرس و غلظت پایین پروتیین پلاسمایی A وابسته به حاملگی در سه ماهه اول بارداری

Background: Previous investigations have shown that pregnancy-associated plasma protein-A (PAPP-A) levels are associated with adverse pregnancy outcomes including intrauterine growth restriction (IUGR) fetuses as well as preterm delivery. The aim of this study was to determine the rate of preterm delivery in women with low PAPP-A and at intermediate risk for chromosomal abnormalities in the first trimester screening. Methods: A total of 137 women who underwent Down syndrome screening between 11 to 14 weeks of gestation were studied from September 2011 to September 2013 at Perinatal Care Clinic, Imam Khomeini Hospital, Ahvaz, Iran. From those, 52 patients had low PAPP-A. Inclusion criteria were singleton pregnancies, at 11 to 14 weeks of gestation, at intermediate risk for Down syndrome (risk in 1:101 to 1:1000). The intermediate risk was estimated based on maternal parameters, maternal serum markers (PAPP-A and β-hcG), and nuchal translucency (NT) using fetal medicine foundation (FMF), UK) software. The power of the study was 90%. The sample size was estimated based on prevalence of preterm delivery in pregnancies with low PAPP-A in the first trimester screening. Patients were followed-up until delivery to observe pregnancy outcomes. We evaluated the variables such as level of PAPP-A, outcomes of delivery, age, β-hCG, and gestational age. Results: Among 137 normotensive pregnant women at intermediate risk for Down syndrome, 52 cases (38%) had low PAPP-A (<0.4 MoM). Of 52, 14 cases (27%) had preterm delivery. None of our patients had pregnancy related or non related diabetes, preeclampsia, or chromosomal anomalies. 45 cases (86%) from 52 patients were equal or less than 35 years, while 7 patients were more than 35 years. Among 52 followed-up patients, 48 patients (92.4%) were at low-intermediate risk (risk in 1:251 to 1:1000), and 4 cases (7.6%) were at high-intermediate risk (risk in 1:101 to 1:250). Conclusion: We found high frequency of preterm delivery in pregnant women with low PAPP-A level at the first trimester screening. Hence, this group of patients needs special and early preventive management. Furthermore, we suggest that future researches to be conducted with larger sample size and also cervix length measurement to be included.