A randomized prospective trial comparing gonadotropin-releasing hormone (GnRH) antagonist/recombinant follicle-stimulating hormone (rFSH) versus GnRH-agonist/rFSH in women pretreated with oral contraceptives before in vitro fertilization

Impact of GnRH ovarian stimulation protocols on intracytoplasmic sperm injection outcomes

BACKGROUND

Although a large number of studies have been conducted in relation to ovarian response and pregnancy after GnRH agonist and GnRH antagonist controlled ovarian hyperstimulation protocols, most of them used single or combinations of a few predictive factors, and none included the stimulation protocol in the multivariable analysis. The present study was thus primarily designed to investigate the predictive value of the stimulation protocol and to analyze the possible relationships between stimulation protocols and treatment outcomes after adjusting for a large set of variables that potentially affect reproductive outcomes. Factors related to pregnancy achievement and predictive of the number of oocytes retrieved and high quality of the embryos obtained were also analyzed.

METHODS

To analyze the impact of GnRH ovarian stimulation protocols on the independent predictors of ovarian response, high quality embryos and clinical pregnancy, two groups out of 278 ICSI treatment cycles were compared prospectively, 123 with a GnRH agonist and 155 with a GnRH antagonist, with multivariable analysis assessing outcomes after adjusting for a large set of variables.

RESULTS

Antagonists were significantly associated with lower length and total dose of GnRH, lower length of rFSH, and higher numbers of oocytes and high quality embryos, whereas the agonist presented a higher fertilization rate and probability of pregnancy. Significant predictors of retrieved oocytes and high quality embryos were the antagonist protocol, lower female age, lower serum levels of basal FSH and higher total number of antral follicles. Significant predictors of clinical pregnancy were the agonist protocol, reduced number of attempts, increased endometrial thickness and lower female age. The probability of pregnancy increased until 30 years-old, with a decline after that age and with a sharp decline after 40 years-old.

CONCLUSION

The models found suggest that not only the protocol but also factors as female age, basal FSH, antral follicles, number of attempts and endometrial thickness should be analyzed for counselling patients undergoing an ICSI treatment.

The effect of oral contraceptive pill for cycle scheduling prior to GnRH-antagonist protocol on IVF cycle parameters and pregnancy outcome

OBJECTIVE

To evaluate the effect of oral contraceptive pills (OCP) pretreatment on IVF cycle outcome in GnRH-antagonist protocol.

DESIGN

Retrospective cohort study.

SETTING

Major tertiary university-affiliated center.

PATIENTS

All patients treated with GnRH antagonist in our IVF unit during the last 3 years were included in the study. Overall 1,799 IVF cycles were performed. Of these, in 604 cycles OCP pretreatment was used prior to GnRH-antagonist for cycle scheduling. Patients were divided into two age groups-young group aged < or = 35 years and older group aged > or = 36 years.

INTERVENTIONS

The young group underwent 927 cycles, 281 cycles with OCP pretreatment and 646 cycles without. The older group underwent 872 cycles, 323 cycles with OCP pretreatment and 549 cycles without. Data was analyzed within each age group.

MAIN OUTCOME MEASURES

Treatment duration and total dose of FSH IU used for stimulation, number of oocytes retrieved, implantation and pregnancy rates.

RESULTS

All OCP-pretreated cycles required significantly longer stimulation than non-pretreated cycles (young: 10.76 vs. 9.21 days; older: 10.48 vs. 8.73 days, respectively) and higher total dose of FSH IU (young: 3,210 IU vs. 2,565 IU; older: 4,973 IU vs. 3,983 IU, respectively). There were no other differences in cycle characteristics between groups. Implantation and pregnancy rates were not affected by OCP pretreatment.

CONCLUSIONS

OCP pretreatment can be offered as a mode for cycle scheduling prior to GnRH-antagonist protocol, though it may be associated with longer stimulation and higher gonadotropin consumption.

Pretreatment with oral contraceptives in infertile anovulatory patients with polycystic ovary syndrome who receive gonadotropins for controlled ovarian stimulation

This study was intended to assess the effects of oral contraceptives given before treatment in infertile anovulatory patients with polycystic ovary syndrome who receive gonadotropins for controlled ovarian stimulation. Pretreatment with oral contraceptives increased the mono-ovulatory cycles, the duration of stimulation for noncanceled cycles, and the number of vials of gonadotropins used. It also reduced the number of dominant follicles and the peak E(2) levels for dominant follicles. No effect was observed in rates of cycle cancellation, pregnancy, abortion, live birth, multiple pregnancies, and ovarian hyperstimulation syndrome.

Gonadotrophin-releasing hormone antagonists for assisted conception: a Cochrane review

Gonadotrophin-releasing hormone (GnRH) antagonists suppress gonadotrophin secretion resulting in dramatic reduction in treatment cycle duration. Assuming comparable clinical outcomes, these benefits may justify changing the standard long GnRH agonist protocol to GnRH antagonist regimens. To evaluate the evidence, databases (e.g. Cochrane Library, MEDLINE, EMBASE) were electronically searched, hand searches were performed, and manufacturers in the field were contacted. Twenty-seven randomized controlled trials (RCT) fulfilled inclusion criteria for comparison of GnRH antagonist with long GnRH agonist protocol. Clinical pregnancy rate and ongoing pregnancy/live-birth rate were significantly lower in the antagonist group (P = 0.009; OR = 0.83, 95% CI 0.72-0.95 and P = 0.02; OR = 0.82, 95% CI 0.68-0.97 respectively). Conversely, incidence of severe OHSS was significantly reduced with the antagonist protocol (P = 0.01; OR = 0.60, 95% CI 0.40-0.88), and interventions to prevent OHSS were administered more frequently in the agonist group (P = 0.03; OR = 0.43, 95% CI 0.20-0.92). Concluding, GnRH antagonist protocols are short, simple, with good clinical outcomes and significant reduction in severe OHSS incidence and gonadotrophin amount; however, the lower pregnancy rate compared with the GnRH agonist long protocol necessitates counselling subfertile couples before recommending change from GnRH agonist to antagonist.

Adding human menopausal gonadotrophin to antagonist protocols – is there a benefit?

The objective of this retrospective analysis was to compare the clinical outcomes of recombinant FSH (r-FSH) with combination r-FSH plus human menopausal gonadotrophin (HMG) protocols in a large private practice using a single IVF laboratory, from 2001 to 2003. Patients underwent ovarian stimulation by standard gonadotrophin-releasing hormone (GnRH) antagonist protocol using r-FSH or combination r-FSH plus HMG. When two or more follicles had attained a minimum mean diameter of 20 mm, follicular triggering was achieved with either recombinant HCG (r-HCG; Ovidrel, 250 microg s.c.) or urinary HCG (u-HCG; 10,000 IU i.m.). The main outcome measures were number of oocytes retrieved and clinical pregnancy rate. There was a lower percentage of cancelled cycles and an increased number of oocytes retrieved, mature oocytes, oocytes that fertilized, embryo that cleaved and a tendency towards higher clinical pregnancy rates in patients treated with r-FSH alone compared with those treated with r-FSH plus HMG. Patients treated with r-FSH plus HMG had lower miscarriage rates and the live birth rate was similar in both treatment groups. In conclusion, irrespective of age, using a treatment regimen consisting of a combination of HMG plus r-FSH was not beneficial compared with r-FSH alone in patients using a GnRH antagonist protocol.

Gonadotropin-releasing hormone antagonist in in vitro fertilization superovulation

The use of gonadotropin-releasing hormone (GnRH) antagonists in in vitro fertilization superovulation remains controversial. The GnRH agonist 'long protocol' has been seen as the gold standard for many years. Comparisons and meta-analyses of the efficacy of GnRH antagonists and agonists have been largely inconclusive, with the dataset being contaminated with outdated reports of poorer efficacy with GnRH antagonists, which have stemmed from studies of their use as a second-line drug in older women and women who were poor responders. This work cannot reflect the actual clinical effectiveness of GnRH antagonist and must be interpreted with care. The major advantages of GnRH antagonists use in superovulation include a gentler and more patient-friendly stimulation cycle with less hypoestrogenic side effects, with the potential to lower the risk of ovarian hyperstimulation and enhanced embryo growth. Our current clinical experience with GnRH antagonists in in vitro fertilization is limited, although there are a growing number of in vitro fertilization centers embracing this new technology. There is a clear need for a modern, suitably powered clinical trial to demonstrate the place of GnRH antagonist-based superovulation protocols and in subgroups of patients, such as polycystic ovary syndrome or poor responders.

Use of oral contraceptives in infertile patients: A descriptive review

In the past and currently, there are several applications of oral contraceptives (OCs) in the field of infertility. The aim of the present descriptive review is to analyze the old and new uses of OCs in infertile patients undergoing simple or multiple ovulation-induction programs. Available data seem to indicate that OCs given before treatment could be effective in patients who are resistant to clomiphene citrate and in poor responders. In addition, the use of OCs is useful for scheduling in vitro fertilization programs downregulated with gonadotropin-releasing hormone-antagonists.

Effects of oral contraceptive, synthetic progestogen or natural estrogen pre-treatments on the hormonal profile and the antral follicle cohort before GnRH antagonist protocol

BACKGROUND

Steroid pre-treatments may be useful to program GnRH antagonist IVF/ICSI cycles. This prospective study assessed hormonal and ultrasound data collected during the free period after the discontinuation of three different pre-treatments to provide information on the optimal time interval required before starting stimulation.

METHODS

Women were randomized to receive oral contraceptive pill (OCP) [ethinyl estradiol (E(2)) 30 microg + desogestrel 150 microg] (n = 21) or norethisterone 10 mg/day (n = 23) or 17-betaE(2) 4 mg/day (n = 25) or no pre-treatment (n = 24) for one cycle before IVF. Assessments were performed on post-treatment day (PD) 1, 3 and 5, or on spontaneous cycle day (CD) 1 and 3.

RESULTS

After OCP and progestogen administration, FSH and LH concentrations shifted from strongly suppressed PD1 levels to PD5 values similar to those observed on CD1. Meanwhile, follicle sizes remained small up to PD5. In contrast, estrogen pre-treatment poorly reduced FSH levels on PD1 compared with OCP or progestogen. Consequently, follicle size was more heterogeneous. FSH rebound was maximal on PD3, whereas LH levels were slightly increased up to PD5.

CONCLUSIONS

A 5-day free interval after OCP or progestogen offers the advantages of gonadotrophin recovery and homogeneous follicular cohort, whereas early FSH rebound occurring after estrogen pre-treatment argues for a short free period.

Among patients treated for IVF with gonadotrophins and GnRH analogues, is the probability of live birth dependent on the type of analogue used? A systematic review and meta-analysis

This systematic review and meta-analysis aimed to answer the following clinical question: among patients treated for IVF with gonadotrophins and GnRH analogues, is the probability of live birth per randomized patient dependent on the type of analogue used? Eligible studies were randomized controlled trials (RCTs), published as a full manuscript in a peer-reviewed journal, that contained sufficient information to allow ascertainment of whether randomization was true and whether equality was present between the groups compared. A literature search identified 22 RCTs comparing GnRH antagonists and GnRH agonists that involved 3176 subjects. Where live birth was not reported in a study that fulfilled the inclusion criteria, an effort was made to contact the corresponding authors to retrieve the missing information. If this was not possible, the reported outcome measure, clinical pregnancy or ongoing pregnancy was converted to live birth in 12 studies using published data (Arce et al., 2005). No significant difference was present in the probability of live birth between the two GnRH analogues [odds ratio (OR), 0.86; 95% confidence intervals (CI), 0.72 to 1.02]. This result remains stable in subgroup analysis that ordered the studies by type of population studied, gonadotrophin type used for stimulation, type of agonist protocol used, type of agonist used, type of antagonist protocol used, type of antagonist used, presence of allocation concealment, presence of co-intervention and the way the information on live birth was retrieved. In conclusion, the probability of live birth after ovarian stimulation for IVF does not depend on the type of analogue used for pituitary suppression.

Influence of pituitary suppression with triphasic or monophasic oral contraceptives on the outcome of in vitro fertilization and embryo transfer

PURPOSE

To compare the clinical outcome of IVF treatment after pituitary suppression with two different oral contraceptives (OCs).

METHODS

65 patients who received IVF treatment was classified into 2 groups based on the difference of OCs they used for pituitary suppression before ovarian hyperstimulation. Group 1 included 36 patients who received monophasic OCs. Group 2 included 29 patients who received triphastic OCs. Both groups received the OCs from the 5th day of the cycle for consecutive 21 days. The hormone profiles after OCs and clinical outcome of IVF treatment were compared between two groups. Two-sample t-tests and X2 tests were used for statistical analyses. P < 0.05 was considered statistically significant.

RESULTS

The mean age and basal hormone profiles were comparable between two groups. After ovulation suppression with different OCs, the day 2 FSH and LH value revealed statistically significant difference between two groups(4.2+/-1.8 vs 6.0+/-2.6; 2.7+/-2.0 vs 4.2+/-3.3 respectively). The numbers of oocyte per retrieval and fertilization rate were comparable between two groups, but higher quality embryos as revealed by the cleavage speed were noted in the triphastic OCs group. Although statistically not significant, higher implantation rate and pregnancy rate were also noted in the triphastic OCs group.

CONCLUSIONS

Different OCs for pituitary suppression can result in different hormone profiles. Ovulation induction in IVF treatment should be individualized according to these hormone changes to achieve the optimal clinical outcome. Triphastic OCs exceeds monophastic OCs in producing good quality embryo in IVF-ET treatment.

Investigation and treatment of repeated implantation failure following IVF-ET

Pregnancy rate following one cycle of IVF and ET can be as high as 60%. But even in the very successful units, some couples fail repeatedly. The causes for repeated implantation failure (RIF) may be because of reduced endometrial receptivity, embryonic defects or multifactorial causes. Various uterine pathologies, such as thin endometrium, altered expression of adhesive molecules and immunological factors, may decrease endometrial receptivity, whereas genetic abnormalities of the male or female, sperm defects, embryonic aneuploidy or zona hardening are among the embryonic reasons for failure of implantation. Endometriosis and hydrosalpinges may adversely influence both. In this mini review, we discuss the suggested methods for evaluation and treatment of RIF: repeated hysteroscopy, myomectomy, endometrial stimulation, immunotherapy, preimplantation genetic screening (PGS), assisted hatching, zygote intra-Fallopian transfer (ZIFT), co-culture, blastocyst transfer, cytoplasmic transfer, tailoring stimulation protocols and salpingectomy for hydrosalpinges.

Gonadotrophin-releasing hormone antagonists for assisted conception

BACKGROUND

Gonadotrophin-releasing hormone antagonists produce immediate suppression of gonadotrophin secretion, hence, they can be given after starting gonadotrophin administration. This has resulted in dramatic reduction in the duration of treatment cycle. Two different regimes have been described. The multiple-dose protocol involves the administration of 0.25 mg cetrorelix (or ganirelix) daily from day six to seven of stimulation, or when the leading follicle is 14 to15 mm, until human chorionic gonadotrophin (HCG) administration and the single-dose protocol involves the single administration of 3 mg cetrorelix on day seven to eight of stimulation. Assuming comparable clinical outcome, these benefits would justify a change from the standard long protocol of GnRH agonists to the new GnRH antagonist regimens.

OBJECTIVES

To evaluate the evidence regarding the efficacy of gonadotrophin-releasing hormone (GnRH) antagonists with the standard long protocol of GnRH agonists for controlled ovarian hyperstimulation in assisted conception.

SEARCH STRATEGY

We searched Cochrane Menstrual Disorders and Subfertility Group's Specialised Register, MEDLINE and EMBASE databases from 1987 to February 2006, and handsearched bibliographies of relevant publications and reviews, and abstracts of scientific meetings. We also contacted manufacturers in the field.

SELECTION CRITERIA

Randomized controlled studies comparing different protocols of GnRH antagonists with GnRH agonists in assisted conception cycles were included in this review.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. If relevant data were missing or unclear, the authors have been consulted

MAIN RESULTS

Twenty seven RCTs comparing the GnRH antagonist to the long protocol of GnRH agonist fulfilled the inclusion criteria. Clinical pregnancy rate was significantly lower in the antagonist group. (OR = 0.84, 95% CI = 0.72 - 0.97). The ongoing pregnancy/ live-birth rate showed the same significant lower pregnancy in the antagonist group (P = 0.03; OR 0.82, 95% CI 0.69 to 0.98).However, there was statistically significant reduction in incidence of severe OHSS with antagonist protocol. The relative risk ratio was (P = 0.01; RR 0.61, 95% CI 0.42 to 0.89). In addition, interventions to prevent OHSS (e.g. coasting, cycle cancellation) were administered more frequently in the agonist group (P = 0.03; OR 0.44, 95% CI 0.21 to 0.93).

AUTHORS' CONCLUSIONS

GnRH antagonist protocol is a short and simple protocol with good clinical outcome with significant reduction in incidence of severe ovarian hyperstimulation syndrome and amount of gonadotrophins but the lower pregnancy rate compared to the GnRH agonist long protocol necessitates counseling subfertile couples before recommending change from GnRH agonist to antagonist..

A randomized controlled trial of increasing recombinant follicle-stimulating hormone after initiating a gonadotropin-releasing hormone antagonist for in vitro fertilization-embryo transfer

OBJECTIVE

Pituitary suppression with a GnRH antagonist before IVF may result in a plateau or decrease in estradiol levels. We sought to investigate the effect of increasing recombinant FSH (rFSH) after starting a GnRH antagonist on estradiol levels, implantation rates, and pregnancy rates.

DESIGN

Prospective, randomized multicenter study.

SETTING

Military medical center and private practice.

PATIENT(S)

Sixty infertile women undergoing IVF who met the appropriate inclusion criteria.

INTERVENTION(S)

Participants were pretreated with combined oral contraceptives (COCs) and received a dose 150-300 IU of rFSH 5 days after taking their last COC. They were randomly assigned to receive their current dose of rFSH (control group) or an additional 75 IU of rFSH (step-up group) after starting a GnRH antagonist. Daily GnRH antagonist injections were started when the lead follicles were 13-14 mm in diameter and continued until hCG was given when two follicles were >or=18 mm. One to three embryos were transferred 3 or 5 days following oocyte retrieval. Women with PCOS, a body mass index >33, a day 3 FSH >14.1 mIU/mL, or prior poor stimulation were excluded.

MAIN OUTCOME MEASURE(S)

The primary endpoints of this pilot study were embryo implantation, pregnancy, and livebirth rates. Secondary endpoints included the amount and days of rFSH; number of days of GnRH antagonist use; estradiol levels on the day of GnRH antagonist initiation, day 1 and day 2 after initiation, and on the day of hCG; endometrial stripe thickness; number of follicles; and number of oocytes.

RESULT(S)

No differences were reported within the groups with respect to age, BMI, baseline FSH, use of intracytoplasmic sperm injection, vials of rFSH, number of GnRH antagonist injections, changes in estradiol patterns, or peak estradiol level. The control and step-up groups had similar pregnancies (73.3% vs. 63.3%, P=.41), clinical pregnancies (70.0% vs. 60.0%, P=.42), live births (56.7% vs. 60.0%, P=.8), and implantation rates (50.0% and 39.1%, P=.22).

CONCLUSION(S)

The use of rFSH and a GnRH antagonist in good candidates for IVF resulted in outstanding implantation and pregnancy rates. Increasing the dose of rFSH after starting a GnRH antagonist does not alter the estradiol response or improve the implantation and pregnancy rates.

A prospective trial comparing oocyte donor ovarian response and recipient pregnancy rates between suppression with gonadotrophin-releasing hormone agonist (GnRHa) alone and dual suppression with a contraceptive vaginal ring and GnRH

BACKGROUND

Contraceptive treatment before gonadotrophin-releasing hormone agonist administration presents advantages in women with a tendency to hyper-response and simplifies donor-recipient treatment synchronization. This study compares response to gonadotrophin stimulation under hypophyseal suppression in oocyte donors with or without vaginal contraceptive pretreatment.

METHODS

One hundred and ninety oocyte donors were recruited in a single centre and prospectively assigned to one of two treatment groups, according to the day of the week menstruation initiated: Group VC-, no prior vaginal contraceptive and Group VC+, prior vaginal contraceptive.

RESULTS

VC+ patients presented a significantly higher cancellation rate, lower plasma estradiol levels and fewer follicles >12 mm on the day of hCG, versus the VC- group. Number of oocytes recovered was significantly lower in the VC+ group. All the cases of severe ovarian hyperstimulation syndrome (SOHSS) were in the VC- group. Pregnancy rates by embryo transfer to synchronic recipients were similar between VC+ and VC- (59.5 versus 57.9%, respectively).

CONCLUSIONS

Vaginal contraceptive pretreatment resulted in a higher ovarian suppression, whereas SOHSS rate was lower than in donors who did not receive pretreatment. There were no differences in pregnancy rates between the two groups of synchronic oocyte recipients.

Cetrorelix in an oral contraceptive-pretreated stimulation cycle compared with buserelin in IVF/ICSI patients treated with r-hFSH: a randomized, multicentre, phase IIIb study

BACKGROUND

The aim of this study was to assess the non-inferiority of an oral contraceptive (OC)-pretreated cetrorelix regimen and a buserelin regimen in IVF/ICSI patients treated with r-hFSH in terms of total number of oocytes retrieved.

METHODS

Multicentre, randomized study. One hundred and eighty two patients were randomized to receive cetrorelix with OC pretreatment (n = 91) or to receive buserelin (n = 91). The cetrorelix group started with daily OCs on cycle day 5 and continued for 21-28 days. Cetrorelix (0.25 mg) was given daily from stimulation day 6 up to and including the day of r-hCG administration. The buserelin group started with buserelin (500 microg/day) for at least 10 days until down-regulation was achieved, after which the dose was reduced to daily 200 microg up to and including the day of r-hCG administration. r-hFSH was started in both groups on a Friday, in the cetrorelix group 5 days after the last OC pill intake. Both regimens were followed by a standard IVF or ICSI procedure. The primary efficacy endpoint was the number of oocytes retrieved per patient.

RESULTS

Number of oocytes, cancellation rates, r-hFSH requirements, number of oocyte retrievals during the weekend or public holiday and number of pregnancies were similar in both groups. Both treatment regimens were well tolerated.

CONCLUSIONS

Cetrorelix pretreated with OCs resulted in similar number of oocytes retrieved compared with a long buserelin protocol. Both regimens were well tolerated and allowed scheduling of the oocyte retrieval, with only small number of retrievals falling on a weekend or public holiday.

Effect of an oral contraceptive pill on follicular development in IVF/ICSI patients receiving a GnRH antagonist: a randomized study

This randomized controlled study compared the effectiveness of a gonadotrophin releasing hormone (GnRH) antagonist protocol with or without oral contraceptive (OC) pretreatment on the number of oocytes retrieved in IVF or intracytoplasmic sperm injection (ICSI) patients. Sixty-four patients were randomized to start recombinant human FSH (r-hFSH) on day 2 or 3 after OC withdrawal (OC group) or on day 2 of a natural cycle (control group). From stimulation day 6 onwards, all patients were treated with daily (0.5 mg/ml) GnRH antagonist (Antide). OC pretreatment resulted in significantly lower starting concentrations of FSH, LH and oestradiol (P < 0.001) and a thinner endometrium (P < 0.0001). In the early stimulation period, fewer large follicles were found after OC pretreatment, leading to a significantly extended stimulation period (11.6 versus 8.7 days, P < 0.0001) with more follicles on the day of recombinant human chorionic gonadotrophin administration (15.4 versus 12.5, P = 0.02) and more oocytes retrieved (13.5 versus 10.2, P < 0.001) as compared with the control group. GnRH antagonist regimen, pretreated with OC, prevented the early endogenous FSH rise and improved follicular homogeneity, resulting in more oocytes. As a consequence of the extended treatment period, more rhFSH was required.

Effect of oral contraceptive pill pretreatment on ongoing pregnancy rates in patients stimulated with GnRH antagonists and recombinant FSH for IVF. A randomized controlled trial

BACKGROUND

The objective of this randomized controlled trial was to assess the effect of oral contraceptive pill (OCP) pretreatment on the probability of ongoing pregnancy in patients treated with a GnRH antagonist for IVF.

METHODS

A fixed dose of 200 IU recombinant FSH (rFSH) was started in 425 patients either on day 2 of the menstrual cycle (non-OCP group: n = 211) or 5 days after discontinuing the OCP (OCP group: n = 214). GnRH-antagonist was initiated on day 6 of stimulation, and triggering of final oocyte maturation was performed with 10,000 IU of HCG.

RESULTS

Ongoing pregnancy rates per started cycle in the non-OCP and OCP group were 27.5% and 22.9%, respectively [95% confidence interval (CI) of the difference: -3.7 to +12.8]. Pregnancy loss was significantly increased in the OCP (36.4%) compared with the non-OCP group (21.6%) (95% CI of the difference: -28.4 to -2.3).

CONCLUSION

Pretreatment with OCP, as compared with initiation of stimulation on day 2 of the cycle in patients treated with GnRH antagonist and recombinant FSH, appears to be associated with a not significant difference in ongoing pregnancy rates per started cycle and results in a significantly higher early pregnancy loss.