Objective: To investigate the effect of induced endogenous hyperprolac
tinemia on the luteinization process, as expressed by the shift in the
P:E(2) ratio after hCG injection in IVF cycles. Patients and Interven
tions: Serum PRL, E(2), and P levels were measured in 49 IVF patients
(leuprolide acetate and hMG protocol) on the day of hCG injection. Est
radiol and P also were measured on the day after hCG. Serum P:E(2) rat
ios were calculated for two groups of patients; group I (control): PRL
less than or equal to 20 ng/mL (conversion factor to SI unit, 1.00);
group II (hyperprolactinemia): PRL > 20 ng/mL. Estradiol and P also we
re measured in follicular fluid (FF) and the gamete performance was co
mpared between groups. Results: Data analysis showed no significant di
fferences in the mean +/- SD serum peak E(2) (pg/mL; conversion factor
to SI unit, 3.671) between groups: group I, 1,769 +/- 843; group II,
2,333 +/- 1,194; the mean FF E(2) (pg/mL) group I, 351 +/- 221; group
II, 370 +/- 186; or the mean FF P (ng/mL; conversion factor to SI unit
, 3.180) group I, 8,357 +/- 3,127; group II, 11,354 +/- 12,888. No sig
nificant differences were found between groups in the P:E(2) ratios on
days 1 or 2: group I, 78 +/- 48 and 209 +/- 137; group II, 70 +/- 47
and 224 +/- 197, respectively. The magnitude of the P shift also showe
d no significant difference between the two groups; the mean +/- SD sh
ift in the P level was 2.9 +/- 2.2 for group I, and 4.3 +/- 5.1 for gr
oup II. The serum PRL level had no effect on the fertilization rate (6
0% for group I and 70% for group II) or on the pregnancy rate (17% for
group I and 23% for group II). Conclusion: These findings suggest tha
t mild endogenous hyperprolactinemia induced by ovarian stimulation do
es not affect granulosa cell luteinization and gamete performance in h
umans.