Stimulated In Vitro Fertilization Cycles Research Articles

Correlation of oocyte number with serum anti-Müllerian hormone levels measured by either Access or Elecsys in fresh in vitro fertilization cycles.

ObjectiveThe aim of this study was to assess the correlation of oocyte number with serum anti-Müllerian hormone (AMH) levels measured by two automated methods (Access or Elecsys) in fresh stimulated in vitro fertilization (IVF) cycles.MethodsIn this retrospective study at a university hospital, data were collected from 243 fresh stimulated IVF cycles performed from August 2016 to December 2020. The serum AMH level was measured by Access in 120 cycles and by Elecsys in 123 cycles. The cut-off of serum AMH for prediction of poor responders (three or fewer oocytes) or high responders (15 or more oocytes) was calculated by the receiver operating characteristic curve analysis.ResultsFor the two automated methods, the following equations were derived: total oocyte number=2.378+1.418×(Access-AMH) (r=0.645, p<0.001) and total oocyte number=2.417+2.163×(Elecsys-AMH) (r=0.686, p<0.001). The following combined equation could be derived: (Access-AMH)=0.028+1.525×(Elecsys-AMH). To predict poor responders, the cut-off of Access-AMH was 1.215 ng/mL (area under the curve [AUC], 0.807; 95% confidence interval [CI], 0.730–0.884; p<0.001), and the cut-off of Elecsys-AMH was 1.095 ng/mL (AUC, 0.848; 95% CI, 0.773–0.923; p<0.001). To predict high responders, the cut-off of Access-AMH was 3.450 ng/mL (AUC, 0.922; 95% CI, 0.862–0.981; p<0.001), and the cut-off of Elecsys-AMH was 2.500 ng/mL (AUC, 0.884; 95% CI, 0.778–0.991; p<0.001).ConclusionBoth automated methods for serum AMH measurement showed a good correlation with oocyte number and good performance for predicting poor and high responders in fresh stimulated IVF cycles. The Access method usually yielded higher measured serum AMH levels than the Elecsys method.

Optimal numbers of mature oocytes to produce at least one or multiple top-quality day-3 embryos in normal responders.

ObjectiveWe attempted to identify the optimal cutoff numbers of mature oocytes that would produce at least one or multiple top-quality (grade A) day-3 embryos in normal responders undergoing stimulated in vitro fertilization (IVF) cycles.MethodsWe selected 210 fresh IVF cycles performed in 170 infertile women at a single center from January 2014 to November 2019. Four to 14 (total) oocytes were obtained in all cycles after conventional ovarian stimulation. A receiver operating characteristic curve analysis was performed to find the moderate and extreme cutoff numbers of mature oocytes that would produce ≥ 1, ≥ 2, ≥ 3, ≥ 4, and ≥ 5 top-quality embryos.ResultsThe cutoff number of mature oocytes was significantly correlated with the number of top-quality embryos (r = 0.467, p= 0.000). The moderate cutoff number of mature oocytes was ≥ 3, ≥ 5, ≥ 5, ≥ 6, and ≥ 6 for obtaining ≥ 1, ≥ 2, ≥ 3, ≥ 4, and ≥ 5 top-quality embryos, respectively. The extreme cutoff number of mature oocytes was ≥ 9, ≥ 9, ≥ 10, ≥ 10, and ≥ 11 for obtaining ≥ 1, ≥ 2, ≥ 3, ≥ 4, and ≥ 5 top-quality embryos, respectively.ConclusionWe present the optimal cutoff numbers of mature oocytes that would yield ≥ 1, ≥ 2, ≥ 3, ≥ 4, and ≥ 5 top-quality embryos with 95% specificity. Our findings could help infertility clinicians to set target mature oocyte numbers in women undergoing stimulated IVF cycles.

Embryonic aneuploidy rates are equivalent in natural cycles and gonadotropin-stimulated cycles

To determine if natural selection and follicular stimulation produces a lower risk for embryonic aneuploidy than that attained following superovulation with exogenous gonadotropins. Prospective observational with historical control group. Large academically affiliated private practice. All patients presenting for their evaluation for infertility were offered participation in the study. All participants in the natural cycle group underwent an unstimulated invitro fertilization (IVF) cycle. A subsequent frozen embryo transfer was performed if a euploid blastocyst was attained. Rates of embryonic aneuploidy attained in unstimulated IVF cycles were compared to those observed in age-controlled historical cohort undergoing conventional stimulated IVF cycles with exogenous gonadotropins. Aneuploidy rates were equivalent in unstimulated and stimulated IVF cycles. The prevalence of aneuploidy in natural cycles increased with the age of the female partner in a manner identical to that seen in stimulated IVF cycles. Finally, sustained implantation rates of euploid blastocysts were equivalent in natural and stimulated IVF cycles. Rates of embryonic aneuploidy are not impacted by follicular stimulation with exogenous gonadotropins. Prior concerns of inducing a higher risk of embryonic aneuploidy are not supported by this data. NCT01866618.

Impact of government health coverage for ART: The results of a 5-year experience in Quebec.

An analysis of national registry data for 5 years of in-vitro fertilization (IVF) funding in Quebec, Canada was compared with the previous complete year of non-funded IVF cycles, as well as the first complete year following the end of funding. The number of cycles, livebirth rates, age group of patients treated, use of donor gametes, multiple pregnancy rates and cycle cancellation rates were assessed. The total number of IVF cycles performed increased dramatically during the funded period, averaging over 10,000 cycles per year. There was no change in the age group distribution of patients treated, but less egg donation was performed. Interestingly, funding was also associated with an increase in the IVF cycle cancellation rate (17.0% versus 34.4%, P < 0.001), a dramatic decline in the multiple pregnancy rate (25.6% versus 4.9%, P < 0.001), and a decline in the livebirth rate per fresh embryo transfer in stimulated IVF cycles (32.3% versus 25.5%, P < 0.001). Although the livebirth rate for stimulated IVF declined, over 9000 babies were born as a result of the coverage. Lessons learned from this experience could help develop a more fiscally responsible programme that still facilitates access to IVF care.

Beliefs, attitudes and funding of assisted reproductive technology: Public perception of over 6,000 respondents from 6 European countries

BackgroundFertility rates in Europe are among the lowest in the world, which may be attributed to both biological and lifestyle factors. Cost and reimbursement of fertility treatments vary across Europe, although its citizens enjoy wide access to fertility care. Since few regional studies evaluating public support for fertility treatment exist, we conducted the Listening IVF and Fertility in Europe (LIFE) survey to ascertain public perception of in vitro fertilization (IVF) and gamete donation as a treatment for infertility among European men and women.Methods and findingsThis survey was distributed via an online questionnaire to 8,682 individuals who were voluntary participants in an online research panel residing in France, Germany, Italy, Spain, Sweden, or the UK. The survey covered items to determine respondents’ beliefs regarding IVF and its success, the need for public funding, the use of IVF among modern families with different lifestyles, and the support for gamete donation. Results were analyzed by age, country of origin, sex, and sexual orientation. A total of 6,110 (70% of total) men and women responded. Among all respondents, 10% had undergone IVF treatment and 48% had considered or would consider IVF in case of infertility. Respondents estimated IVF mean success rate to be 47% and over half of respondents believed that availability of IVF would encourage people to delay conception. Although 93% of respondents believed that IVF treatment should be publicly funded to some extent, a majority believed that secondary infertility or use of fertility treatments allowing to delay parenthood should be financed privately. Survey respondents believed that the mean number of stimulated IVF cycles funded publicly should be limited 2 to 3 (average 2.4). 79% of respondents were willing to pay for IVF if needed with a mean amount of 5,400 € for a child brought to life through IVF. According to respondents, mean minimum and maximum ages for IVF should be 29 and 42 years old, respectively. The current survey showed support for egg and sperm donation (78%), for IVF in single women (61%) and for same-sex female couples (64%). When analyzing the results per group (i.e., sex, age, sexual orientation, and countries), youngest age groups, homosexuals, bisexuals, German respondents, and men had similar overall positive attitudes and beliefs toward IVF and opinions on public funding. Perceived limits to availability were stronger in women.ConclusionOverall, the survey results demonstrate a positive attitude among respondents in an online panel toward IVF, gamete donation, and support for public funding for fertility treatment. These findings could potentially drive discussions between patients and prescribers to explore IVF treatment and among legislators and payers to support public funding for these procedures.

The use of in vitro maturation in stimulated antagonist in vitro fertilization cycles of normo-hyperresponder women due to arrested follicular development: A rescue procedure.

Objective: To evaluate the impact of rescue in vitro maturation (IVM) on the clinical outcomes of women with arrested follicular development in stimulated in vitro fertilization (IVF) cycles.Materials and Methods:This is a retrospective review of 13 patients who were evaluated as normo-hyperresponders for ovarian stimulation. The main outcome measure was the clinical pregnancy and livebirth rates. The purpose of gonadotropin stimulation in patients undergoing IVF is to retrieve multiple oocytes by avoiding multifetal gestation and Ovarian Hyperstimulation syndrome (OHSS). The ovarian response to stimulation ranges from poor response to OHSS, which is related to the follicular number and the dose of the gonadotropins used. However, in some cycles of normo-hyperresponder women, follicular development decelerates or ceases. Close follow-up in a daily manner and increasing the dose of gonadotropins did not change the follicular arrest. This clinical situation has two edges; one is cycle cancellation, which has undesired psychological outcomes for women and the IVF team, and second one is the prolongation of the IVF cycle. For such circumstances, IVM may be a valuable option. Stimulated IVF cycles were converted to IVM as a rescue IVM procedure following detailed informed consent of the women who were close to cycle cancellation.Results:Thirteen 13 IVM cycles and their clinical outcomes are presented. Six women achieved pregnancies, but only 4 delivered 5 healthy live born. The other two women had biochemical loss during follow-up.Conclusion:Based on the data obtained, it can be concluded that gonadotropin-stimulated cycles with follicular arrest at the edge of cancellation can be shifted to rescue IVM procedures with reasonable clinical outcomes.

A randomized controlled trial with addition of letrozole as an adjunct to FSH in high responders in stimulated IVF cycles show negative impact of ovarian stimulation on the endomterium

Can letrozole reduces the incidence of premature progesterone rises late follicular phase, and thus impact positively on endometrial receptivity to high responders in stimulated in vitro fertilization (IVF) cycles? A randomized parallel controlled trial This randomized parallel controlled trial was conducted in from the Hospital from October 2015 to August 2016.Altogether 133 women undergoing IVF treatment were randomized into two groups using computer-generated randomization plan, to one of the following two treatment regimens: A standard GnRH-a protocol and 100 IU-225IU recFSH were applied from stimulation day 1 and letrozole 2.5 mg/day from cycle day 5 to the day before hCG administration (Letrozole group, n=69) or none (control group, n=64).Standard luteal phase support with progesterone were provided. While estradiol levels were significantly lower in the letrozole group (P < 0.001), the progesterone levels (1.09±0.40,0.93±0.38)ng/ml and P/E2(0.74,0.30) (P < 0.05) on the day of hCG administration were increased in the letrozole group. RecFSH , the recovery rate of eggs, Fertilization rate, high-quality embryo rate,thickness of endometrium,were similar between the letrozole and control groups. Clinical pregnancy rate: 58.5%(31/53),72.9%(35/48) was lower in the letrozole group, although there was no statistical significance by T test( P=0.128 ). The results suggest that co-treatment with letrozole can not reduce the incidence of premature progesterone rise at the late follicular phase,thus show negative impact on endometrial receptivityin in stimulated IVF cycles.With no increase in clinical pregnancy rates compared with control group in high responders undergoing assisted reproductive technology.

Nomogram to predict the number of oocytes retrieved in controlled ovarian stimulation.

ObjectiveOvarian reserve tests are commonly used to predict ovarian response in infertile patients undergoing ovarian stimulation. Although serum markers such as basal follicle-stimulating hormone (FSH) or random anti-Müllerian hormone (AMH) level and ultrasonographic markers (antral follicle count, AFC) are good predictors, no single test has proven to be the best predictor. In this study, we developed appropriate equations and novel nomograms to predict the number of oocytes that will be retrieved using patients' age, serum levels of basal FSH and AMH, and AFC.MethodsWe analyzed a database containing clinical and laboratory information of 141 stimulated in vitro fertilization (IVF) cycles performed at a university-based hospital between September 2009 and December 2013. We used generalized linear models for prediction of the number of oocytes.ResultsAge, basal serum FSH level, serum AMH level, and AFC were significantly related to the number of oocytes retrieved according to the univariate and multivariate analyses. The equations that predicted the number of oocytes retrieved (log scale) were as follows: model (1) 3.21–0.036×(age)+0.089×(AMH), model (2) 3.422–0.03×(age)–0.049×(FSH)+0.08×(AMH), model (3) 2.32–0.017×(age)+0.039×(AMH)+0. 03×(AFC), model (4) 2.584–0.015×(age)–0.035×(FSH)+0.038×(AMH)+0.026×(AFC). model 4 showed the best performance. On the basis of these variables, we developed nomograms to predict the number of oocytes that can be retrieved.ConclusionOur nomograms helped predict the number of oocytes retrieved in stimulated IVF cycles.

Endometrial vascularity is lower in pregnancies with pregnancy‐induced hypertension or small‐for‐gestational‐age fetus in live birth after in‐vitro fertilization

To assess the relationship between endometrial/subendometrial vascularity and the risk of pregnancy-induced hypertension (PIH) or small-for-gestational-age (SGA) fetuses in women who had a live birth following in-vitro fertilization (IVF). This was a retrospective study of women who had a live birth after IVF from November 2002 to December 2004. Only women with a singleton pregnancy (n = 104) were included for analysis. Three-dimensional ultrasound measurement with power Doppler of the endometrial and subendometrial regions was performed on the day of oocyte retrieval in stimulated IVF cycles or on luteinizing hormone surge + 1 day in frozen-thawed embryo transfer cycles to measure the endometrial volume and the vascularization index (VI), flow index (FI) and vascularization flow index (VFI) of the endometrial and subendometrial regions. Pregnancy outcomes were also reviewed. Eight women (7.7%) had PIH or an SGA fetus. Women in the PIH/SGA group had significantly lower endometrial VI (0.504 vs 1.051; P = 0.023) and VFI (0.121 vs 0.253; P = 0.023) than those in the non-PIH/SGA group. However endometrial FI was significantly higher in the PIH/SGA group (23.04 vs 22.71; P = 0.028). There were no significant differences in subendometrial indices between the two groups. Women who had a live birth following IVF and whose pregnancy was complicated by PIH or an SGA fetus had significantly lower endometrial vascularity in terms of VI and VFI than did women without PIH or SGA.

Ovulation trigger with less than 3 follicles in stimulated in-vitro fertilization (IVF) cycles: a retrospective study

In stimulated IVF cycles, ovulation trigger is usually performed in the presence of 3 or more mature follicles. This minimal number is based on clinical experience rather than on strong literature, and obtained by weighing the probability of implantation and pregnancy versus the risk of not reaching embryo transfer when so few mature follicles are present. This study aims to evaluate if triggering ovulation in a stimulated IVF cycle with only 2 dominant follicles or less (measuring 14 mm or more) results in pregnancy rates comparable to those obtained with 3 follicles (the currently used triggering threshold).

Overnight maturation of a metaphase I oocyte retrieved from a natural cycle using human tubular fluid: a case report

Since the first successful pregnancy and live birth was achieved through natural cycle in vitro fertilization (IVF) in 1978 [1], there have been many technological advancements and refinements of protocols and techniques through the years [2]. Ovarian hyperstimulation was favored over unstimulated cycles, due to the increased number of embryos available for transfer and hence increased success rate. However, stimulated IVF is also associated with side effects such as ovarian hyperstimulation syndrome [3] and it is costly [4]. For patients who have failed to conceive after repeated stimulated IVF cycles, natural cycle IVF may be a cost-saving alternative [5, 6] which allows patients to avoid further exposure to the side effects associated with stimulated IVF cycles [7, 8]. However, one of the drawbacks of pure natural cycle IVF is its higher cancellations rates (28.9 % per cycle) and lower pregnancy rate (0 to 12.5 % per cycle) [5]. The main reasons for cancellation are premature ovulation before oocyte retrieval, failure to retrieve oocytes and retrieval of immature oocytes. The stage of maturation of the oocyte cannot be determined before retrieval as well. When an immature oocyte is retrieved, it is usually discarded and the cycle is cancelled. To maximize the utilization of the immature oocytes collected from unstimulated cycles, our centre evaluated our protocol and started incubating the immature oocytes overnight in human tubular fluid (HTF) (Irvine Scientific, USA) instead of discarding them. Standard IVF culture media has been shown to be as efficacious as specialized IVM media in ‘rescuing’ immature oocytes retrieved from standard stimulated IVF cycles [9]. When fully matured, the oocytes are fertilized, allowed to develop into embryos in culture and eventually transferred. We report the first case of a successful implantation and pregnancy achieved from this ‘rescue’ protocol in a natural IVF cycle.

Recurrence of empty follicle syndrome with stimulated IVF cycles

Aim: To determine the incidence of recurrent empty follicle syndrome (EFS) and to analyse the factors associated with this phenomenon. Methods: Retrospective analysis comparing all EFS cycles with cycles in which oocytes were retrieved in our in vitro fertilization (IVF) unit between 1998 and 2006. Results: Of 8292 IVF cycles, 163 (2.0%) resulted in empty follicles. Risk factors for EFS included advanced age (37.7 ± 6.0 years vs. 34.2 ± 6.0 years, p < 0.001), longer infertility (8.8 ± 10.6 years vs. 6.3 ± 8.4 years, p < 0.05), higher baseline follicle-stimulating hormone levels (8.7 ± 4.7 IU/L vs. 6.7 ± 2.9 IU/L, p < 0.001) and lower E2 levels before the human chorionic gonadotropin injection (499.9 ± 480.9 pg/mL vs. 1516.3 ± 887.5 pg/mL, p < 0.001) compared with cases in which ova were retrieved. Among patients with EFS, recurrent EFSs occurred in 15.8% of subsequent cycles. Conclusion: The EFS is a sporadic event in the majority of patients. However, in about 16% of the patients, EFS may recur. These cases may be a variant form of poor response and patients with repetitive EFS syndrome should be counseled concerning their chances to conceive.

Two-dimensional largest ovarian area to predict ovarian response in in vitro fertilization cycle

Objective: To evaluate the usefulness of two dimensional largest ovarian area (LOA) as a predictive parameter of oocyte yield and pregnancy in in vitro fertilization (IVF) cycle. Methods: Ninety-two stimulated IVF cycles from sixty-eight infertile women were included. On the day 3 of cycles, antral follicle count (AFC) and LOA were measured by ultrasonography before starting gonadotropins. LOA was calculated by ellipsoid formula (D1×D2×0.8) using two perpendicular diameters in the largest cross-sectional view of each ovary and then summed. Results: Both LOA and AFC had a positive correlation with the number of retrieved oocytes. The best cut-off value of LOA was 6.14 cm2 for predicting poor ovarian response (area under curve [AUC], 0.783; 95% confidence interval [CI], 0.684 to 0.862), 7.70 cm2 for predicting cycle cancellation (AUC, 0.794; 95% CI, 0.697 to 0.871) and 8.36 cm2 for predicting pregnancy (AUC, 0.641; 95% CI, 0.534 to 0.739). For AFC, the best cut-off value was 9 for poor ovarian response (AUC, 0.877; 95% CI, 0.792 to 0.936), 6 for predicting cycle cancellation (AUC, 0.942; 95% CI, 0.872 to 0.980) and 9 for pregnancy (AUC, 0.683; 95% CI, 0.578 to 0.776). The predictability for pregnancy was similar between LOA and AFC. Conclusion: LOA is easy to measure and a good marker for predicting ovarian response and IVF pregnancy.

The efficiency of progesterone vaginal gel versus intramuscular progesterone for luteal phase supplementation in gonadotropin-releasing hormone antagonist cycles: a prospective clinical trial

We compared the efficiency of progesterone vaginal gel (PVG) with intramuscular progesterone (IMP) supplementation for luteal phase support after in vitro fertilization and embryo transfer in gonadotropin-releasing hormone (GnRH) antagonist cycles. The treatment outcomes were similar for PVG and IMP for luteal support in GnRH-antagonist protocols. With its ease of use, high tolerability by patients, and fewer side effects, PVG can be a successful alternative to IMP.

Preimplantation genetic screening outcomes are associated with culture conditions

Although preimplantation genetic screening (PGS) is widely offered, there are contradictory reports on the clinical merit of this procedure. Any gain from embryo selection following aneuploidy screening must significantly outweigh the impact of the procedure. Variability of technical expertise in embryo biopsy, blastomere fixation, fluorescence in situ hybridization analysis, along with suboptimal laboratory quality control and inappropriate patient selection may impact PGS outcomes. To investigate such effects, a total of 1508 stimulated in vitro fertilization (IVF) cycles were retrospectively analysed. During 2004, a significant change was made to the embryo culture media used. Clinical outcomes from cycles with PGS were compared prior to and after the change in media and compared with matched controls not utilizing PGS during the same period. Clinical PGS success rates were found to improve following the media change. For patients aged less than 40, clinical outcomes following PGS were significantly lower than those without PGS prior to the change, but became equivalent after the change. For patients >or=40 years and <or=2 previous stimulated IVF cycles, clinical outcomes with PGS were similar to those without PGS prior to the change but became significantly improved after the change. These results suggest that a laboratory procedure change may significantly impact PGS patient outcomes.

Luteinizing response to human chorionic gonadotropin does not predict outcome in gonadotropin releasing hormone agonist-suppressed/human menopausal gonadotropin-stimulated in vitro fertilization (IVF) cycles.

The purpose of this study was to determine if early luteinizing potential in gonadotropin releasing hormone agonist (GnRH-a)-suppressed/human menopausal gonadotropin (hMG)-stimulated IVF cycles is predictive of cycle outcome. The study was a prospective evaluation of 41 women beginning a GnRH-a-suppressed/hMG-stimulated IVF cycle. The in vitro fertilization program of a tertiary care institution was the study setting. The main outcome measures were (1) estradiol (E2) and progesterone (P) levels on the day of human chorionic gonadotropin (hCG) administration and the following day and (2) the ovarian response to ovulation induction and clinical outcome. Ten of the 41 women achieved a clinical pregnancy (24.4%). There was no significant difference in progesterone (P) levels on the day of or the day following hCG administration between the pregnant and the nonpregnant groups. Both groups exhibited a significant rise in P level in response to hCG. There was no significant difference in E2 levels on the day of hCG between the two groups. The serum E2 did not rise significantly in response to hCG in either group. Patients who became pregnant had significantly more oocytes retrieved, fertilized, cleaved, and transferred. Clinical response and outcome in GnRH-a-suppressed/hMG-stimulated IVF cycles are not predicted by early luteinizing potential as indicated by the response of E2 or P to hCG.

Assessing the early luteal phase in in vitro fertilization cycles: relationships between plasma steroids, endometrial receptors, and endometrial histology

The corpus luteum-endometrial unit was investigated in in vitro fertilization (IVF) cycles using endocrine, morphologic, and biochemical measurements on the day normally scheduled for embryo transfer (day 16), in 12 stimulated and 4 natural cycles. Advanced endometrial histologic maturity was recorded in 9 of the 12 stimulated cycles. No in-phase endometria were seen when the preovulatory plasma estradiol (E2) was greater than 500 pg/ml or the day 16 plasma progesterone (P) greater than 10 ng/ml in natural or stimulated cycles. Significant negative correlations were noted between both preovulatory E2 and day 16 P and the concentration of cytosolic progesterone receptor (PRc). Advanced endometrial maturity tended to be associated with low concentrations of PRc. Regardless of endometrial maturity, the natural cycle was characterized by low cytosolic E2 receptors (ERc) and high PRc, whereas the concentration of both receptors was usually greatly reduced in stimulated cycles. It is concluded that the advanced endometrial maturation observed in stimulated IVF cycles is a consequence of the production of supraphysiologic levels of sex steroids by the corpus luteum that cause profound modifications of endometrial receptor dynamics.

Embryo quality and uterine receptivity in in-vitro fertilization cycles with or without agonists of gonadotrophin-releasing hormone

The proportion of abnormal oocytes or embryos per recovered oocyte in in-vitro fertilization (IVF) cycles had no influence on the occurrence of pregnancy following the transfer of normal embryo(s) derived from oocytes capable of fertilization. There were more implantations per transferred embryo in stimulated IVF cycles using long-acting buserelin (30.0%) compared with short-acting decapeptyl (17.3%) or no gonadotrophin-releasing hormone agonist (GnRHa, 15.2%) treatments. However, the chances of implantation per embryo transferred being in excess of one in patients who became pregnant tended to be higher in non-GnRHa (23.5%) compared to buserelin- (16.4%) or decapeptyl- (13.3%) treated IVF cycles. Moreover, frozen--thawed embryos had a higher implantation rate (P less than 0.05) when originating from IVF cycles without GnRHa (11.7%) compared to GnRHa-treated cycles (buserelin, 4.3%; decapeptyl, 5.9%). It can be concluded that GnRHa associated with gonadotrophins produced embryos of a poorer aptitude for development than stimulation treatments without GnRHa. The clinical efficacy of GnRHa in IVF--ET cycles could be the result of an improved uterine receptivity to the transferred embryos.