GnRH antagonists and endometrial receptivity in oocyte recipients: a prospective randomized trial.

The effect that gonadotrophin-releasing hormone (GnRH) antagonists exert on endometrial receptivity has not yet been elucidated. GnRH antagonists might directly affect oocytes, the embryo and/or the endometrium. The aim of this study was to investigate the direct effect of GnRH antagonists on the endometrium in oocyte donation cycles. In an oocyte donation programme, oocytes from each donor (n = 49), stimulated with gonadotrophins and a GnRH antagonist, were equally shared between two different matched recipients. Recipients were randomly allocated to either receive a GnRH antagonist concomitant to donor during their endometrial priming with oestradiol (group I, n = 49) or to solely continue with their endometrial preparation (group II, n = 49). Pregnancy rate was 55.1% in group I and 59.1% in group II. Implantation rate was 26.1% in group I and 24.4% in group II. Endometrial thickness was also similar between the two groups on the day of human chorionic gonadotrophin injection to the donor. In conclusion, GnRH antagonist administration during the proliferative phase at a dose of 0.25 mg per day does not appear to adversely affect endometrial receptivity in oocyte recipients.

Low-dose human chorionic gonadotropin during the proliferative phase may adversely affect endometrial receptivity in oocyte recipients.

The effect of low-dose human chorionic gonadotropin (hCG) administration in the proliferative phase of oocyte recipients was investigated in a prospective randomized trial. Sibling oocytes from the same donor were shared at random among two different recipients. In group I oocyte recipients received 750 IU of hCG every three days concomitant to endometrial preparation with estradiol until hCG injection to the donor, whereas in group II recipients received no hCG during endometrial priming with estradiol. Endometrial thickness was significantly lower in group I compared with group II, although similar endometrial thickness was detected during the mock cycle. Pregnancy rates were significantly lower in group I than in group II (13.6% vs. 45.4%, p<0.05). Implantation rates were also significantly lower in group I (1.7% vs. 22.4%, p<0.01). The study was discontinued prematurely for ethical reasons when 22 cycles were completed, as pregnancy rates were very low in group I. In conclusion, hCG administration in the proliferative phase might directly affect endometrial proliferation and receptivity.

Effect of clomiphene citrate on follicular and luteal phase luteinizing hormone concentrations in in vitro fertilization cycles stimulated with gonadotropins and gonadotropin-releasing hormone antagonist.

OBJECTIVE: To investigate the effect that clomiphene citrate exerts on luteinizing hormone (LH) concentrations in gonadotropin/gonadotropin-releasing hormone (GnRH) antagonist cycles. DESIGN: Retrospective analysis. SETTING: Tertiary referral center. PATIENT(S): Two groups of patients undergoing in vitro fertilization (IVF) were compared. In group I, 20 patients were stimulated with clomiphene citrate (CC) in combination with gonadotropins and 0.25 mg of Cetrorelix (ASTA Medica AG; Frankfurt am Main, Germany) and in group II, 20 patients were stimulated with gonadotropins and 0.25 mg of Cetrorelix. INTERVENTION(S): Blood sampling was performed in the late follicular, periovulatory, early, mid, and late luteal phases. MAIN OUTCOME MEASURE(S): Luteinizing hormone (LH), estradiol, and progesterone. RESULT(S): LH levels were significantly higher in group I than in group II on all the days studied. Progesterone serum concentrations were significantly higher in group II in the early luteal phase, but not in the follicular or the middle and late luteal phases. CONCLUSION(S): LH concentrations are significantly higher in the follicular and luteal phases in cycles stimulated with CC, despite GnRH antagonist administration. This observation might have implications for the dose of GnRH antagonist needed to suppress LH in the follicular phase and questions the need for luteal-phase supplementation in cycles in which CC was used.

Endometrial hormone receptors and proliferation index in the periovulatory phase of stimulated embryo transfer cycles in comparison with natural cycles and relation to clinical pregnancy outcome.

OBJECTIVE: To investigate the endometrial steroid receptors and proliferation index in GnRH analogue/hMG-stimulated cycles in comparison with natural cycles and their relation to clinical pregnancy outcome. DESIGN: Prospective observational study. SETTING: Tertiary referral center. PATIENT(S): Twenty-seven stimulated patients with GnRH agonist and hMG. Twenty normo-ovulatory patients were the natural cycle controls. INTERVENTION(S): Endometrial aspiration biopsies: in stimulated cycles on the day of oocyte retrieval within the ET cycle (Day OPU) (n = 20) or 2 days later (Day OPU + 2) (n = 7); in natural cycles on the natural day of ovulation (Day NO) (n = 10) or on the day of ovulation + 2 (Day NO + 2) (n = 10). MAIN OUTCOME MEASURE(S): Comparison of endometrial maturation, estrogen (ER) and P receptor (PR), and proliferation index by immunohistochemistry in natural and stimulated cycles, correlation with pregnancy outcome in stimulated cycles. RESULT(S): Stimulated cycles Day OPU showed significantly advanced endometrial maturation compared to natural cycles Day NO; stromal ER and glandular and stromal PR staining was lower in stimulated than in natural cycles, but higher on Day OPU than on Day NO + 2; proliferation index was lower in all stimulated cycles. Steroid receptors and proliferation index in stimulated cycles were unrelated to clinical pregnancy occurrence. CONCLUSION(S): Compared to natural cycles, ovarian stimulation induced an imbalance in endometrial ER and PR and led to a profound antimitotic effect in the peri-ovulatory phase. These parameters were, however, not predictive of clinical pregnancy in cycles with ET.

Endometrial integrin expression in the early luteal phase in natural and stimulated cycles for in vitro fertilization.

OBJECTIVE: To investigate the effect of ovarian stimulation on integrin expression in the early luteal phase. STUDY DESIGN: Seven endometrial biopsies were taken 2 days after the oocyte retrieval from stimulated cycles for IVF and 23 from natural cycles, 2 days after ovulation. RESULT: Endometrium was in-phase in 22/23 and 7/7 biopsies from the natural and stimulated cycles, respectively. Integrins alpha(1) and alpha(4) were simultaneously positive in 43.4% from the natural and in all (100%) the stimulated cycles (P<0.03). On the day of the endometrial biopsy, progesterone serum values were higher in the stimulated cycles (55.2+/-9.5 microg/l versus 8.5+/-3.8 microg/l) (P<0.001). HSCORE value was significantly higher in stimulated cycles for both integrins. CONCLUSION: Endometrial integrin expression is more consistently present in the early luteal phase in stimulated cycles than in natural cycles and this may be related to the higher serum progesterone concentration and/or the more advanced endometrial histological features.

Luteal hormonal profile of oocyte donors stimulated with a GnRH antagonist compared with natural cycles.

The effect of gonadotrophin-releasing hormone (GnRH) antagonist treatment on luteal phase hormonal profile has not yet been fully investigated. Cycle characteristics of 23 fertile donors stimulated with recombinant FSH and the GnRH antagonist, ganirelix 0.25, for IVF and receiving no kind of luteal supplementation were compared with control, natural cycles. Luteal luteinizing hormone (LH) serum concentrations as well area under the curve (AUC) for LH were significantly higher in natural cycles. In addition, luteal phase length was longer in natural cycles compared with donor cycles. Luteinizing hormone values dropped in the luteal phase of the stimulated cycles, with the lowest values being observed in the mid-luteal phase. AUC for progesterone in the luteal phase was significantly higher in the stimulated cycles compared with natural cycles (P < 0.001). Low LH serum concentrations and shortened luteal phase indicate the need for luteal phase supplementation in GnRH antagonist IVF cycles.

The impact of LH serum concentration on the clinical outcome of IVF cycles in patients receiving two regimens of clomiphene citrate/gonadotrophin/0.25 mg cetrorelix.

Clomiphene citrate treatment with the association of gonadotrophins and the GnRH antagonist cetrorelix 0.25mg was analysed in two different stimulation protocols for IVF. In protocol I, 18 patients were sequentially stimulated with clomiphene citrate and gonadotrophins. In protocol II, 28 patients started the gonadotrophin injections during the clomiphene citrate administration. LH values significantly dropped after the first 0.25 mg cetrorelix injection in both protocols. A total of 22% and 7% of cycles were cancelled in protocols I and II, respectively, because of poor follicular development. The clinical pregnancy rate following embryo transfer was 18.1% in protocol I and 29.1% in protocol II. In two (11.1%) cycles stimulated according to protocol I and in eight (28.5%) cycles from protocol II, premature LH surges occurred. In patients with premature LH surge, significantly fewer metaphase II oocytes were obtained. The clinical pregnancy rate following embryo transfer was 12.5% in patients with surge compared with 29.6% in patients without. LH values were lower before HCG injection in patients who achieved pregnancy in the study cycle. In conclusion, sequential clomiphene citrate and gonadotrophin administration is not recommended for clomiphene citrate/gonadotrophin/cetrorelix 0.25 cycles. Cetrorelix 0.25 mg/day was associated with a high incidence of premature LH surges and premature LH surges were associated with an adverse cycle outcome.