Evaluation of Triple Test Results and Determining the Median of Serum Markers for Early Diagnosis of First-Trimester Congenital Anomalies

Early diagnosis and termination of the pregnancies with abnormal fetuses in early stages of pregnancy can prevent from giving birth to disabled infants who will impose burden to their family and community. The aim of this study was to determine the median of serum markers in order to identify the congenital anomalies in the first trimester through performing triple tests screening. In this prospective study, 127 pregnant women referring in their first trimester to obstetric clinic of Omul-Banin Hospital (Mashhad, Iran, Feb 2009-May 2010) were enrolled whose gestational age ranged between 11 weeks and 13 weeks + 6 days. All patients were evaluated with a single sonologist. In each case, fetal nuchal translucency (NT) thickness and CRL were measured and recorded in specific questionnaire designed for triple test results. Maternal serum free beta-human chorionic gonadotropin (Freeβ-HCG) and pregnancy- associated plasma protein-A (PAPP-A) were afterwards measured and recorded in the questionnaire. Our measurements showed that NTs ranged from 1.1 to 2.7mm (Mean=1.62mm). In older mothers (³35 years) the rate of NT was higher than those of other ages. The serum free β-HCG and PAPP-A had no relation with the maternal age. Based on laboratory results of serum markers, median index was determined for free β-HCG and PAPP-A. This index was 127.30 ng/mL for free β-HCG and 24.688 mg/L for PAPP-A, respectively. According to the results of present study, the basic risk for developing fetal anomalies can be achieved by having determined medians (for free b-hCG and PAPP-A), NT, MoM, maternal age, gestational age and other relevant variables. Using specified softwares, these anomalies would be, thus, diagnosed in the first trimester of pregnancy.