Hyperglycosylated human chorionic gonadotropin and the source of pregnancy failures.
OBJECTIVE
To investigate the proportion of hyperglycosylated human chorionic gonadotropin (hCG-H) produced at the time of implantation as a predictor of pregnancy success.


METHODS
Measuring daily urine hCG and hCG-H on the day of implantation. The time of implantation was assumed to be the first day of hCG detection (total hCG >1 mIU/mL).


METHODS
Urine samples were collected at volunteers' homes throughout city of Albuquerque.


METHODS
110 women attempting to conceive spontaneously; 62 achieved pregnancies (42 to term and 20 failed).


METHODS
None.


METHODS
Measurements of the total hCG and hCG-H, and calculations of the proportion of hCG-H.


RESULTS
In all 42 term pregnancies, the proportion of hCG-H on the day of implantation was >50%. This was also true for 7 of the 20 failures. Statistically significant lower proportions of hCG-H (<50%) were observed in 13 of 20 pregnancies that eventually failed. The predictive values of proportion of hCG-H, concentration of hCG-H, total hCG, and regular hCG alone for detecting failures were 100%, 59%, 41%, and 21%, respectively.


CONCLUSIONS
Hyperglycosylated is produced by cytotrophoblast cells in early pregnancy at the time of implantation. Effective proportions of hCG-H (>50%) are required for successful growth and invasion by cytotrophoblasts at the time of implantation. Low proportions of hCG-H at implantation predict failure and are likely to be the root of many pregnancy failures. The 7 of 20 failures with normal proportions of hCG-H were likely due to genetic, immune, or maternal causes. Measurement of a proportion of hCG-H <50% on the day of implantation absolutely indicates a failing pregnancy.
USA hCG Reference Service, Division of Women's Health Research, Department of Obstetrics and Gynecology, University of New Mexico, Albuquerque, New Mexico 87131, USA.
Yasushi
Y
Sasaki
Donald G
DG
Ladner
Laurence A
LA
Cole
D000022:Abortion, Spontaneous / Q000453:epidemiology*; D006063:Chorionic Gonadotropin / Q000378:metabolism / Q000652:urine*; D010064:Embryo Implantation; D005260:Female; D006031:Glycosylation; D006801:Humans; D009516:New Mexico / Q000453:epidemiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D050497:Stillbirth / Q000453:epidemiology; D014327:Trophoblasts / Q000502:physiology
D006063:Chorionic Gonadotropin