First-trimester maternal serum human chorionic gonadotrophin as a marker for fetal chromosomal disorders

1992 ◽  
Vol 12 (6) ◽  
pp. 495-504 ◽  
Author(s):  
J. M. M. Van Lith ◽  
Keyword(s):  
First Trimester ◽  
Maternal Serum ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Chromosomal Disorders

Human chorionic gonadotrophin and subunit composition of maternal serum and coelomic and amniotic fluids in the first trimester of pregnancy

1992 ◽  
Vol 135 (3) ◽  
pp. 563-569 ◽  
Author(s):  
R. K. Iles ◽  
N. C. Wathen ◽  
D. J. Campbell ◽  
T. Chard
Keyword(s):  
First Trimester ◽  
Maternal Serum ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Subunit Composition ◽  
Major Constituent ◽  
Coelomic Fluid ◽  
Α Subunit ◽  
First Trimester Of Pregnancy ◽  
Β Hcg

ABSTRACT Sixteen matched samples of first trimester amniotic fluid (AF), extraembryonic coelomic fluid (EECF) and maternal serum (MS) were assayed for intact human chorionic gonadotrophin (hCG) and free subunits. Total β-hCG (free β-subunit and intact hCG) levels in the EECF (median 410 kIU/l) were 61 times greater than levels in AF (median 6·73 kIU/l) and 2·8 times greater than in MS (median 141·5 kIU/l). Levels of intact hCG in the EECF (median 245 kIU/l) were 142 times greater than in AF (median 1·73 kIU/l) and 1·6 times greater than in MS (median 157 kIU/l). Free α-subunit levels in EECF (median 17·3 mg/l) were 66 times greater than in AF (median 0·262 mg/l) and 12 times greater than in MS (median 1·3 mg/l). Virtually all of the total β-hCG immunoreactivity in MS can be attributed to intact hCG, but only 60% of total β-hCG in the EECF and 20% of that in AF can be accounted for by the intact hormone. In both EECF and AF the free α-subunit was a major constituent; on a molar basis the ratio of free α:free β:intact hCG was 1:1·2:0·3 in AF, 1:0·6:0·5 in EECF and 1:0:5 in MS. Chromatography of MS, EECF and AF on Sephadex G-100 confirmed the hCG and subunit composition of the fluids. On the basis of these findings it seems likely that previous studies showing very high levels of hCG in AF during the first trimester may have incorrectly sampled the EECF. In reality, the levels of total hCG (and free subunits) are low in the AF, and only 20% is intact hCG. In both AF and EECF the free subunits may have been derived by dissociation of intact hormone, or possibly by independent synthesis. These and other findings suggest that either the amnion acts as a barrier to the transfer of proteins or that there may be dynamic removal from this compartment. By contrast, the EECF might act as a relatively stable reservoir for these proteins. Journal of Endocrinology (1992) 135, 563–569

Total amount of circulating human chorionic gonadotrophin α and β subunits in first trimester trisomies 21 and 18

1996 ◽  
Vol 148 (1) ◽  
pp. 27-31 ◽  
Author(s):  
E Jauniaux ◽  
K H Nicolaides ◽  
A-M Nagy ◽  
M Brizot ◽  
S Meuris
Keyword(s):  
Trisomy 21 ◽  
First Trimester ◽  
Maternal Serum ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Trisomy 18 ◽  
Serum Samples ◽  
Significant Difference ◽  
Common Unit ◽  
Α And Β Subunits

Abstract The aim of this study was to evaluate the variations in the balance between total (free and combined) circulating α and β subunits of human chorionic gonadotrophin (hCG) in trisomy 21 and 18. Maternal serum samples were collected at 10 and 11 weeks of gestation from 22 singleton pregnancies with trisomy 21 (n=17) and trisomy 18 (n=5) and 66 chromosomally normal controls, matched for gestational age. The hCG and free α and β subunits circulating levels were measured using specific immunoradiometric assays and converted in a common unit system obtained using calibration of the assays with intact and thermally dissociated purified hCG preparation. In trisomy 21, the only significant difference from controls was in the free βhCG level which was increased. In trisomy 18, intact hCG, free βhCG as well as total αhCG and total βhCG levels were significantly lower whereas the free αhCG level was significantly higher than in controls. The decrease in total βhCG was more pronounced than the decrease in total αhCG resulting in a significant increase in the total α- to βhCG subunit ratio in trisomy 18. These findings suggest some modifications in the biosynthesis and/or release rates of the hCG subunits in these trisomies. Journal of Endocrinology (1996) 148, 27–31

Maternal serum human chorionic gonadotrophin and pregnancy-associated plasma protein A in twin pregnancies in the first trimester

2002 ◽  
Vol 22 (3) ◽  
pp. 183-185 ◽  
Author(s):  
Marko Niemimaa ◽  
Mikko Suonpää ◽  
Seppo Heinonen ◽  
Maija Seppälä ◽  
Risto Bloigu ◽  
...  
Keyword(s):  
Plasma Protein ◽  
Protein A ◽  
First Trimester ◽  
Maternal Serum ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Twin Pregnancies
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