Maternal serum median levels of alpha-foetoprotein, human chorionic gonadotropin & unconjugated estriol in second trimester in pregnant women from north-west India

BACKGROUND & OBJECTIVES Triple test as prenatal screening procedure does not form a part of routine health care of pregnant women in India. Hence, median values of triple test biomarkers are lacking for Indian population. This study was undertaken to establish population-specific medians for biomarkers viz. alpha-foetoprotien (AFP), human chorionic gonadotropin (hCGβ), and unconjugated estriol (uE3) for detection of Down's syndrome, Edward's syndrome and neural tube defects (NTDs) in pregnant women in north-west India. METHODS Serum biomarker values were derived from 5420 pregnant women between 15-20 wk of gestation who were enrolled for triple test investigations at Department of Gynecology and Obstetrics, Government Medical College and Hospital, Chandigarh, India, between January, 2007 to December, 2009. Median values were calculated for rounded weeks using database comprising pregnancies with normal outcomes only. Simple statistical analysis and log-linear regression were used for median estimation of the biomarker values. RESULTS The levels of the three biomarkers were found to be ranging from 1.38 to 187.00 IU/ml for AFP, 1.06 to 315 ng/ml for hCGβ, and 0.25 to 28.5 nmol/l for uE3. The age of women ranged from 18 to 47 yr and mean weight was 57.9 ± 9.8 kg. Data revealed that AFP, hCGβ and uE3 medians in our study population were not significantly different from those reported from other countries or when compared ethnically. INTERPRETATION & CONCLUSION The population-specific median values for the three biomarkers (AFP, hCGβ, uE3) may be used as reference values during prenatal screening in Indian pregnant women.