Maternal Serum Markers as Second Trimester Screening for Chromosomal Aneuploidies and Neural Tube Defects Followed by their Diagnosis and Impact on the Outcome of the Pregnancy

Background: As we are aware serum markers estimation is currently in use to screen aneuploidies and neural tube defects as prenatal care should be offered to all if possible, or at least high-risk patients. Down syndrome (DS) has major socio-economic and psychological implications being the most frequent cause of mental handicap in developing world countries. Objective: The present study was aimed at detecting the aneuploidies and other neural tube defects by second-trimester quadruple biochemical marker screening along with sonographic soft markers to compute risk assessment in current pregnancy followed by their impact on detection and deciding medical termination of pregnancy if patient desires. Methods: This study was carried out in pregnant women undergoing quadruple screening tests between June 2020 and June 2021. Biomarkers alpha-fetoprotein, human chorionic gonadotropin, unconjugated-estriol and inhibin A were tested, and risk of a pregnancy being affected with Down Syndrome, Edward?s syndrome, Patau syndrome or Neural Tube Defects were calculated. Screen-positive patients were referred for con?rmatory amniocentesis/NIPT. A follow-up of screen-positive patients were carried out by telephonically whether they continued or terminated the pregnancy in covid era. Results: Out of 200 pregnant women who underwent quadruple marker screening, 8 (4%) were screen-positive, including all 8 positives for Down syndrome. Out of eight, three cases were confirmed as DS by amniocentesis. No case of trisomy 13/18 was detected. All confirmed patients terminated the pregnancy (100% termination rate), rest continued the pregnancy. One fetus was detected with hydrocephalous and cleft palate in anomaly scan who was screened negative forthe quadruple marker. Conclusions: Quadruple screening in the second trimester is reasonably effective for the detection of major chromosomal defects and NTDs who come for their first antenatal visit in 2nd trimester.