EnglishPregnancy
Pregnancy tests are based on the detection of elevated levels of human Chorionic Gonadotrophin (hCG) in serum or urine, which is produced by the developing placenta following implantation. The appearance and rapid rise in the level of hCG makes it an excellent marker for pregnancy. Urine and serum samples of non-pregnant females usually contain less than 5 mIU/ml hCG3. After conception levels of hCG in a normal pregnancy will increase rapidly with levels reaching between 100,000 – 200,000 mIU/ml at the end of the first trimester1,2,4,5,6.
1. Braunstein G.D., Rasor J., Adler D., Danzer H. & Wade M.E. (1976) Serum human Chorionic Gonadotrophin levels throughout normal pregnancy. Am. J. Obstet. Gynecol. 126(6), 678-681.
2. Chard T. (1992) Pregnancy test – a review. Human Reproduction. 7(5), 701-710.
3. Alfthan H., Hagland C., Dabek J. & Stenman U.H. (1992) Concentrations of human Chorionogonadotropin, its b -subunit, and the core fragment of the b -subunit in serum and urine of men and non-pregnant women. Clin. Chem. 38(10), 1981-1987.
4. Lenton E.A., Neal L.M. & Sulaiman R. (1982) Plasma concentrations of human Chorionic Gonadptrophin from the time of implantation until the second week of pregnancy. Fertil. Steril. 37(6), 773-778.
5. Lau H.L., Lawrence K.W., Linkins S.E. & Jones G.S. (1978) Early detection of human Chorionic Gonadotrophin in urine by simple immunoassays. Am. J. Obstet. Gynecol. 132(6), 691-693.
6. Hsu M.I., Kolm P., Leete J., Dong K.W., Mausher S. & Oehninger S. (1998) Analysis of implantation in Assisted Reproduction through Use of Serial hCG Measurements. J. Assisted Reprod Genetics. 15(8) 496-505.