HUMAN MENOPAUSAL GONADOTROPIN INCREASES PREGNANCY RATE IN COMPARISON WITH CLOMIPHENE CITRATE DURING REPLACEMENT CYCLES OF FROZEN THAWED PRONUCLEATE OVA/
I. Vanderauwera et al., HUMAN MENOPAUSAL GONADOTROPIN INCREASES PREGNANCY RATE IN COMPARISON WITH CLOMIPHENE CITRATE DURING REPLACEMENT CYCLES OF FROZEN THAWED PRONUCLEATE OVA/, Human reproduction, 9(8), 1994, pp. 1556-1560
In a prospective randomized study, the effect of two ovulation inducti
on regimens on implantation rate of frozen/thawed pronucleate ova was
investigated. Patients received either human menopausal gonadotrophin
(HMG) or clomiphene/HMG. Ovulation induction was done on an individual
basis using ultrasound and plasma 17 beta-oestradiol concentrations.
Ovulation was induced with human chorionic gonadotrophin (HCG) when th
e leading follicle reached a diameter of 18 mm. Pronucleate ova had be
en frozen using the slow-freezing method of Lassalle et al. (1985) (Fe
rtil. Steril., 44, 645- 651) and were thawed in synchrony with the age
of the endometrium. Both groups of patients were comparable for age,
indication for in-vitro fertilization, pre-ovulatory 17 beta-oestradio
l concentration, number of large follicles and number and quality of e
mbryos transferred. The only difference found was that HCG was adminis
tered 1 day earlier in the HMG group compared to the clomiphene/HMG gr
oup (P < 0.01). Using univariate analysis, the pregnancy rate was high
er in patients stimulated, with HMG alone compared to those stimulated
with clomiphene/HMG (27 versus 15% respectively; P < 0.03), when HCG
was administered later in the menstrual cycle (P < 0.01) and when more
and better quality embryos were transferred (P < 0.01). Using multiva
riate regression analysis, the influence of the stimulation on pregnan
cy rate was even more pronounced (P < 0.01) when the day of HCG admini
stration and the number and quality embryos transferred were taken int
o account. Therefore, we conclude that HMG alone increases pregnancy r
ate compared to clomiphene/HMG during replacement cycles of frozen/tha
wed pronucleate ova. These data suggest that HMG results in a better e
ndometrium receptivity for embryos. This could be important not only f
or embryo replacement cycles but also for ovulation induction in gener
al.