Serum chorionic gonadotropin

Figure 54-8 Computation of median values for maternal serum chorionic gonadotropin (CG) in the second trimester. The observed average gestational age from Table 54-4 is plotted on the horizontal axis and the median of that week s CG measurements on the vertical logarithmic axis.The thin vertical lines represent the 95% confidence intervals of the medians.The line represents the results of a nonlinear regression analysis weighted by the square root of the number of samples.The equation of that curve in completed weeks is CG median = 39.69 X 5 93 7he corresponding equation...

Bogart MH, Pandian MR, Jones OW. Abnormal maternal serum chorionic gonadotropin levels in pregnancies with fetal chromosome abnormalities. Prenat Diagn 1987 7 623-30. 

Blomberg, K., Hurskainen, P. and Hemmila, I. (1999). Terbium and rhodamine as labels in a homogeneous time-resolved fluorometric energy transfer assay of the b-subunit of human chorionic gonadotropin in serum. Clin. Chem. 45, 855-61. 

R.G. Richards, S.M. Hartman, and S. Handwerger. Human cytotrophoblast cells cultured in maternal serum progress to a differentiated syncytial phenotype expressing both human chorionic gonadotropin and human placental lactogen. Endocrinology. 135 321-329 (1994). 

The increased risk of trisomy with advanced maternal age motivates more than half of pregnant women in North America to undergo prenatal diagnosis (most commonly, amniocentesis or chorionic villus sampling, discussed in Oiapter 6). Down syndrome can also be screened by assaying maternal serum levels of a-fetoprotein, chorionic gonadotropin, and unconjugated estriol. This so-called triple screen can detect approximately 70% of fetuses with Down syndrome. 

Shapiro BS, Daneshmand ST, Garner FC, Aguirre M, Ross R, Morris S. Effects of the ovulatory serum concentration of human chorionic gonadotropin on the incidence of ovarian hyperstimulation syndrome and success rates for in vitro fertilization. Fert Steril 2005 84 93-8. 

Four-week-old C57B1/6 females are super-ovulated with pregnant mare serum 2 d prior to mating and with human chorionic gonadotropin hormone on the day of mating with C57B1/6 males. 

G4. Givens, C. R., Schriock, E. D., Dandekar, P. V., and Martin, M. C., Elevated serum progesterone levels on the day of human chorionic gonadotropin administration do not predict outcome in assisted reproduction cycles. Fertil. Steril. 62, 1011-1017 (1994). 

L2. Laufer, N., DeChemey, A. H., Tarlatzis, B. C., and Naftolin, F., The association between preovulatory serum 17 beta-estradiol pattern and conception in human menopausal gonadotropin-human chorionic gonadotropin stimulation. Fertil. Steril. 46, 73—76 (1986). 

Evaluation of the Stratus immunoassay system in the determination of serum levels of human chorionic gonadotropin and cortisol. Clin. Chem. 32, 1117, Abstr. 334. 

Figure 54-3 Concentration of chorionic gonadotropin (CG) in maternal serum as a function of gestational age. Lines represent the 2nd, 50th, and 97th percentiles.The maternal serum values from 14 to 25 weeks are medians calculated from 24,229 pregnancies from testing performed at ARUP Laboratories Inc, from January to October 1997, fRedrawn fromAshwood R. Evaluating health and maturation of the unborn the role of the clinical laboratory. Clin Chem 1992 38 1523-1529. Permission granted from Clin Chem.)...

Figure 54-10 A comparison of the associations between gestational age and the four second trimester maternal serum markers for Down syndrome. For each of the analytes, the median at 15 weeks gestation has been assigned a value of 100%. Each subsequent median is represented as a percentage of that initial median. The marker that has the weakest association with gestational age is dimeric inhibin A (DIA).The strongest associations are found for unconjugated estriol (uEa) and chorionic gonadotropin (CG).The association between gestational age and alpha fetoprotein (AFP) is intermediate.

Daily CA, Laurent SL,- Nunley WCJ. The prognostic value of serum progesterone and quantitative P-human chorionic gonadotropin in early human pregnancy. Am J Obstet Gynecol 1994 171 380-3. 

Macri JN, Kasturi RV, Krantz DA, Cook EJ, Moore ND, Young JA, et al. Maternal serum Down syndrome screening free p-protein is a more effective marker than human chorionic gonadotropin. Am J Obstet Gynecol 1990 163 1248-53. 

O Leary P, Nichols C, Feddema P, Lam T> Aitken M. Serum progesterone and human chorionic gonadotropin measurements in the evaluation of ectopic pregnancy. Aust NZ J Obstet Gynaecol 1996 36 319-23. 

Ooi DS, Perkins SL, Claman P, Muggah HE, Serum human chorionic gonadotropin levels in early pregnancy. Clin Chim Acta 1989 181 281-92. 

Wald N, Cuckle H, Wu TS, George L. Maternal serum unconjugated oestriol and human chorionic gonadotropin levels in twin pregnancies implications for screening for Down s syndrome. Br J Obstet Gynaecol 1991 98 905-8. 

In the past decade several lines of evidence have shown that human chorionic gonadotropin (hCG) is a thyroid stimulator and may cause hyperthyroidism. The basis for the thyrotropic effect of hCG is the structural similarity of hCG to TSH (similar a subunits and unique /3 subunits). In hyperthyroid patients with very high hCG levels, serum TSH may be inappropriately detectable owing to the weak crossreactivity of hCG in the radioimmunoassay for TSH. In patients with hyperthyroidism caused by trophoblastic tumors, serum hCG levels usually exceed 300 units/mL and always exceed 100 units/mL. The mean peak hCG level in normal pregnancy is 50 units/mL. On a molar basis, hCG has only 1/10,000 the activity of pituitary TSH in mouse bioassays. Nevertheless, this thyrotropic activity may be very substantial in patients with trophoblastic tumors, whose serum hCG concentrations may reach 2000 units/mL. 

Nakamura, Y., Ono, M., Nakata, M., Tamura, H., Takiguchi, S., Sugino, N., Shimamura, K., and Kato, H. (1996). Nitric oxide synthase (NOS) activity in the ovary during ovulation in immature rats injected pregnant mare serum gonadotropin (PMSG)-human chorionic gonadotropin (hCG). Biol.Reprod. 54 68. (Abstract). 

Van E>en Bosch et al. (VI) measured serum alkaline phosphatase in boys with delayed puberty who had been given very short courses of chorionic gonadotropin. The mean value almost doubled within 5 weeks of this medication. 

ADP AFP ab as ALAT AP ASAT ATP BQ BSA CEH CK CME COD con A CV d D E E EC ECME EDTA EIA /e FAD FET FIA G GOD G6P-DH HBg HCG adenosine diphosphate a-fetoprotein antibody antigen alanine aminotranferase alkaline phosphatase aspartate aminotransferase adenosine triphosphate benzoquinone bovine serum albumin cholesterol ester hydrolase creatine kinase chemically modified electrode cholesterol oxidase concanavalin A coefficient of variation (relative standard deviation) layer thickness diffusion coefficient enzyme potential Enzyme Classification enzyme-chemically modified electrode ethylene diamine tetraacetic acid enzyme immunoassay enzyme loading factor flavin adenine dinucleotide field effect transistor flow injection analysis amplification factor glucose oxidase glucose-6-phosphate dehydrogenase hepatitis B surface antigen human chorionic gonadotropin... 

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