Free alpha-subunits of human chorionic gonadotropin in preeclampsia.
OBJECTIVE
To investigate free alpha-human chorionic gonadotropin (hCG) as a marker of preeclampsia.


METHODS
Four groups of patients were studied: normal pregnancies, preeclampsia, eclampsia and normal pregnant women <20 weeks' gestation. Patients were further divided according to parity and gestational age (< or =20, 21-30, 31-40 weeks). An immunoradiometric assay employing monoclonal antibodies specific for free alpha-hCG was used.


RESULTS
A total of 313 patients were analyzed. Thirty-four patients < or =20 weeks' gestation were followed until delivery: five (14.7%) developed preeclampsia; none had abnormal alpha-hCG levels before onset of preeclampsia. Patients with preeclampsia (21-30 weeks' gestation) demonstrated a mean alpha-hCG level greater than that of normotensive controls but this was not statistically significant. Between 31 and 40 weeks' gestation, mean alpha-hCG levels in the hypertensive and control groups were 210.8 ng/ml and 115.8 ng/ml, respectively (P < 0.001). A stronger association was observed between alpha-hCG and preeclampsia with increasing gestational age (relative risk [RR] 2.07, 21-30 weeks; RR 3.02, 31-40 weeks) and severity (RR 4.51, mild; RR 12.15, severe; RR 16.88, eclampsia).


CONCLUSIONS
There is a strong association between alpha-hCG and preeclampsia, nevertheless this test is unsuitable for predicting preeclampsia.
Moodley
D
D
Department of Obstetrics and Gynaecology, Faculty of Medicine, University of Natal, Durban, South Africa.
Moodley
J
J
Buck
R
R
Haneef
R
R
Payne
A
A
D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004461:Eclampsia / Q000097:blood*; D005260:Female; D005865:Gestational Age; D015292:Glycoprotein Hormones, alpha Subunit / Q000097:blood*; D006801:Humans; D015592:Immunoradiometric Assay; D010298:Parity; D011225:Pre-Eclampsia / Q000097:blood*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D015203:Reproducibility of Results; D012306:Risk; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
D015415:Biomarkers; D015292:Glycoprotein Hormones, alpha Subunit