Ag. Andersen et al., TIME-INTERVAL FROM HUMAN CHORIONIC-GONADOTROPIN (HCG) INJECTION TO FOLLICULAR RUPTURE, Human reproduction, 10(12), 1995, pp. 3202-3205
The aim of this study was to estimate the time interval from human cho
rionic gonadotrophin (HCG) injection to follicular rupture, Furthermor
e, it was observed whether there was any effect on the pregnancy rate
if the insemination was performed at the time of follicular rupture, I
n a programme of intrauterine insemination 37 consecutive cycles in 32
patients were monitored after stimulation with clomiphene citrate. HC
G was administered by i.m. injection when a leading follicle of at lea
st 18 mm in diameter was observed sonographically. All patients were m
onitored by sonography with 1 h intervals from 32 h after HCG injectio
n until the first rupture of a follicle, Insemination was performed im
mediately after the first follicular rupture, The pregnancy rate was 1
6% (5/32). In 66%, the largest follicle was the first to rupture, The
mean time interval from HCG administration to first follicular rupture
was 38.3 h (SEM = 0.54; range = 34-46). Our findings support the conc
ept that ovulation occurs about 38 h after HCG administration, The pre
gnancy rate was within the normal range, although insemination was per
formed at the time of follicular rupture, The largest follicle was not
always the first to rupture.