Screening chromosomal anomalies in early pregnancy: When and why.

Prenatal screening for aneuploidies is done using maternal serum and sonographic markers. Although many screening tests are available, their correct application still does not have uniformity. This review will give insight into the existing screening protocols, their merits and demerits, interpretation of results and the relevance of these tests in low resource settings. Cell free fetal DNA and its exciting role in non invasive prenatal testing along with its advantages and drawbacks is also taken up. We have further considered the role of counseling and its importance before embarking on the screening tests. The upcoming role of maternal serum markers for prediction of adverse obstetrical outcomes is also discussed. [ABSTRACT FROM AUTHOR]