Characterization of the normal progesterone and placental protein 14 responses to human chorionic gonadotropin stimulation in the luteal phase.
OBJECTIVE
To examine whether midluteal phase administration of the luteotrophic hormone hCG can result in higher and more stable serum levels than random sampling of P and placental protein 14 (PP14).


METHODS
Prospective controlled clinical study.


METHODS
Normal human volunteers in an academic research environment.


METHODS
Twenty-six fertile, regularly cycling women.


METHODS
Blood samples were drawn at 0, 3, 6, 9, 12, 18, and 24 hours and then daily for the next 6 days, after a single IM injection of 5,000 IU hCG or saline given on day 5, 7, or 9 after the LH surge, as detected by rapid plasma assays.


METHODS
Serum P and PP14 measurements.


RESULTS
Peak P and PP14 concentrations occurred at 6 hours and 5 days, respectively, after hCG stimulation on luteal phase day 9. Progesterone but not PP14 levels were significantly higher and less variable after hCG than after saline administration on this day. Progesterone responses exceeded 11.0 ng/mL (35.0 nmol/L) in all women, suggesting that this represents the cutoff limit for normal luteal function. Because PP14 responses were highly variable and inconsistent, it was not possible to determine a threshold for normal endometrial function.


CONCLUSIONS
Midluteal phase administration of hCG in normal women induces consistent serum P levels > 11.0 ng/mL (35.0 nmol/L) but highly variable PP14 responses.
Batista
M C
MC
Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892.
Cartledge
T P
TP
Nieman
L K
LK
Bravo
N
N
Loriaux
D L
DL
Merriam
G R
GR
D000328:Adult; D006063:Chorionic Gonadotropin / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D000071816:Glycodelin; D006023:Glycoproteins; D006801:Humans; D007700:Kinetics; D008183:Luteal Phase / Q000187:drug effects*; D011257:Pregnancy Proteins / Q000097:blood*; D011374:Progesterone / Q000097:blood*; D011446:Prospective Studies
D006063:Chorionic Gonadotropin; D000071816:Glycodelin; D006023:Glycoproteins; C045246:PAEP protein, human; D011257:Pregnancy Proteins; D011374:Progesterone