Increased concentration of the free beta-subunit of human chorionic gonadotropin in hyperemesis gravidarum.
OBJECTIVE
The amount of free beta subunit hCG (free beta) has been reported to be increased in trophoblast disease and Down's syndrome, conditions also associated with high total hCG. Increased total hCG has been reported in hyperemesis gravidarum. We sought to determine if sera from singleton gestations with hyperemesis gravidarum contained a higher proportion of free beta hCG compared to controls of comparable gestational age.


METHODS
Sera from 39 patients with hyperemesis gravidarum was compared with that from 23 control subjects of comparable gestational age with respect to beta hCG and its subunits (free beta and free alpha).


RESULTS
Hyperemesis patients and controls were comparable with respect to age, weight and gestational age. The concentration of hCG was greater in hyperemesis patients (9237 +/- 3613 ng/ml, mean +/- s.d.) compared to controls (5543 +/- 2290, p < 0.005) as was the concentration of free beta hCG (101 +/- 70 ng/ml vs. 31 + 31, p < 0.001). Free alpha did not differ between hyperemesis patients and controls (399 +/- 231 ng/ml vs. 377 +/- 214). A percent free beta greater than 0.6 was found in 33/39 hyperemesis patients (85%) compared to 5/23 controls (22%), p < 0.001.


CONCLUSIONS
Increased free beta hCG is found in hyperemesis gravidarum. This finding strengthens the association of hyperemesis with abnormal metabolism of hCG.
Goodwin
T M
TM
Department of Obstetrics and Gynecology, University of Southern California.
Hershman
J M
JM
Cole
L
L
D000328:Adult; D000367:Age Factors; D001835:Body Weight; D006063:Chorionic Gonadotropin / Q000097:blood* / Q000378:metabolism; D004314:Down Syndrome / Q000209:etiology; D005260:Female; D005865:Gestational Age; D006801:Humans; D006939:Hyperemesis Gravidarum / Q000097:blood*; D011247:Pregnancy; D014327:Trophoblasts
D006063:Chorionic Gonadotropin