The use of the GnRH analogue buserelin for IVF--does it improve fertility?

Oral medications including clomiphene citrate or aromatase inhibitors with gonadotropins for controlled ovarian stimulation in women undergoing in vitro fertilisation

BACKGROUND

Gonadotropins are the most commonly used medications for controlled ovarian stimulation in in vitro fertilisation (IVF). However, they are expensive and invasive, and are associated with the risk of ovarian hyperstimulation syndrome (OHSS). Recent calls for more patient-friendly regimens have led to growing interest in the use of clomiphene citrate (CC) and aromatase inhibitors with or without gonadotropins to reduce the burden of hormonal injections. It is currently unknown whether regimens using CC or aromatase inhibitors such as letrozole (Ltz) are as effective as gonadotropins alone.

OBJECTIVES

To determine the effectiveness and safety of regimens including oral induction medication (such as clomiphene citrate or letrozole) versus gonadotropin-only regimens for controlled ovarian stimulation in IVF or intracytoplasmic sperm injection (ICSI) treatment.

SEARCH METHODS

We searched the following databases: Cochrane Gynaecology and Fertility Group Specialised Register (searched January 2017), the Cochrane Central Register of Controlled Trials (CENTRAL CRSO), MEDLINE (1946 to January 2017), Embase (1980 to January 2017), and reference lists of relevant articles. We also searched trials registries ClinicalTrials.gov (clinicaltrials.gov/) and the World Health Organization International Clinical Trials Registry Platform (www.who.int/trialsearch/Default.aspx). We handsearched relevant conference proceedings.

SELECTION CRITERIA

We included randomized controlled trials (RCTs). The primary outcomes were live-birth rate (LBR) and OHSS.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trial eligibility and risk of bias. We calculated risk ratios (RR) and Peto odds ratio (OR) with 95% confidence intervals (CIs) for dichotomous outcomes and mean differences (MD) for continuous outcomes. We analyzed the general population of women undergoing IVF treatment and (as a separate analysis) women identified as poor responders. We assessed the overall quality of the evidence using the GRADE approach.

MAIN RESULTS

We included 27 studies in the updated review. Most of the new trials in the updated review included poor responders and evaluated Ltz protocols. We could perform meta-analysis with data from 22 studies including a total of 3599 participants. The quality of the evidence for different comparisons ranged from low to moderate. The main limitations in the quality of the evidence were risk of bias associated with poor reporting of study methods, and imprecision.In the general population of women undergoing IVF, it is unclear whether CC or Ltz used with or without gonadotropins compared to use of gonadotropins along with gonadotropin-releasing hormone (GnRH) agonists or antagonists resulted in a difference in live birth (RR 0.92, 95% CI 0.66 to 1.27, 4 RCTs, n = 493, I2 = 0%, low-quality evidence) or clinical pregnancy rate (RR 1.00, 95% CI 0.86 to 1.16, 12 RCTs, n = 1998, I2 = 3%, moderate-quality evidence). This means that for a typical clinic with 23% LBR using a GnRH agonist regimen, switching to CC or Ltz protocols would be expected to result in LBRs between 15% and 30%. Clomiphene citrate or Ltz protocols were associated with a reduction in the incidence of OHSS (Peto OR 0.21, 95% CI 0.11 to 0.41, 5 RCTs, n = 1067, I2 = 0%, low-quality evidence). This means that for a typical clinic with 6% prevalence of OHSS associated with a GnRH regimen, switching to CC or Ltz protocols would be expected to reduce the incidence to between 0.5% and 2.5%. We found evidence of an increase in cycle cancellation rate with the CC protocol compared to gonadotropins in GnRH protocols (RR 1.87, 95% CI 1.43 to 2.45, 9 RCTs, n = 1784, I2 = 61%, low-quality evidence). There was moderate quality evidence of a decrease in the mean number of ampoules used,) and mean number of oocytes collected with CC with or without gonadotropins compared to the gonadotropins in GnRH agonist protocols, though data were too heterogeneous to pool.Similarly, in the poor-responder population, it is unclear whether there was any difference in rates of live birth (RR 1.16, 95% CI 0.49 to 2.79, 2 RCTs, n = 357, I2 = 38%, low-quality evidence) or clinical pregnancy (RR 0.85, 95% CI 0.64 to 1.12, 8 RCTs, n = 1462, I2 = 0%, low-quality evidence) following CC or Ltz with or without gonadotropin versus gonadotropin and GnRH protocol. This means that for a typical clinic with a 5% LBR in the poor responders using a GnRH protocol, switching to CC or Ltz protocols would be expected to yield LBRs between 2% to 14%. There was low quality evidence that the CC or Ltz protocols were associated with an increase in the cycle cancellation rate (RR 1.46, 95% CI 1.18 to 1.81, 10 RCTs, n = 1601, I2 = 64%) and moderate quality evidence of a decrease in the mean number of gonadotropin ampoules used and the mean number of oocytes collected, though data were too heterogeneous to pool. The adverse effects of these protocols were poorly reported. In addition, data on foetal abnormalities following use of CC or Ltz protocols are lacking.

AUTHORS' CONCLUSIONS

We found no conclusive evidence indicating that clomiphene citrate or letrozole with or without gonadotropins differed from gonadotropins in GnRH agonist or antagonist protocols with respect to their effects on live-birth or pregnancy rates, either in the general population of women undergoing IVF treatment or in women who were poor responders. Use of clomiphene or letrozole led to a reduction in the amount of gonadotropins required and the incidence of OHSS. However, use of clomiphene citrate or letrozole may be associated with a significant increase in the incidence of cycle cancellations, as well as reductions in the mean number of oocytes retrieved in both the general IVF population and the poor responders. Larger, high-quality randomized trials are needed to reach a firm conclusion before they are adopted into routine clinical practice.

Clomiphene citrate and letrozole to reduce follicle-stimulating hormone consumption during ovarian stimulation: systematic review and meta-analysis

OBJECTIVE

To assess the available evidence comparing effectiveness of ovarian stimulation (OS) using clomiphene citrate (CC) and/or letrozole (LTZ) to reduce follicle-stimulating hormone (FSH) consumption compared with standard OS.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials that compared reproductive outcomes following in-vitro fertilization. We searched 11 electronic databases and hand-searched the reference lists of included studies and related reviews. We stratified the results, separating studies according to the oral agent used (CC or LTZ) and the characteristics of the included women (expected poor ovarian response or other women). When combining the results of the included studies, we assessed the relative risk (RR) for live birth, clinical pregnancy, miscarriage and cycle cancelation, the Peto odds ratio (OR) for ovarian hyperstimulation syndrome (OHSS) and mean difference (MD) for the number of oocytes retrieved and FSH consumption.

RESULTS

A total of 22 studies were included in the review. Considering women with expected poor ovarian response, the available evidence suggested that using CC to reduce FSH consumption during OS provided similar rates of live birth (RR, 0.9 (95% CI, 0.6-1.2), moderate-quality evidence) and clinical pregnancy (RR, 1.0 (95% CI, 0.8-1.4), moderate-quality evidence); the use of LTZ did not cause a relevant change in the number of oocytes retrieved (MD, -0.4 (95% CI, -0.9 to 0.1), high-quality evidence). Considering the studies evaluating other women, the available evidence suggested that using CC to reduce FSH consumption during OS reduced the number of oocytes retrieved (MD, -4.6 (95% CI, -6.1 to -3.0), high-quality evidence) and risk of OHSS (Peto OR, 0.2 (95% CI, 0.1-0.3), moderate-quality evidence), while results were similar for rates of live birth (RR, 0.9 (95% CI, 0.7-1.1), moderate-quality evidence) and clinical pregnancy (RR, 1.0 (95% CI, 0.8-1.1), high-quality evidence). The quality of the evidence was low or very low for other outcomes.

CONCLUSION

The use of CC to reduce FSH consumption in women with expected poor ovarian response has the advantage of providing similar reproductive outcomes with reduced costs. For the other women, the use of CC for reducing FSH consumption has the additional advantage of reducing OHSS, but also reduces the total number of oocytes retrieved. More studies are needed to evaluate the effect of LTZ for the same purpose. Future studies should focus on cumulative pregnancy per oocyte retrieval, patient dissatisfaction and agreement to repeat the cycle if not pregnant, which are important outcomes for clinical decisions. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Clomiphene citrate in combination with gonadotropins for controlled ovarian stimulation in women undergoing in vitro fertilization

BACKGROUND

Gonadotropins are the most commonly used medication for controlled ovarian stimulation in in vitro fertilization (IVF). However, they are expensive, invasive and are associated with risk of ovarian hyperstimulation syndrome (OHSS). With recent calls for patient friendly IVF, there has been an interest in the use of clomiphene citrate with or without gonadotropins to reduce the burden of injections. However, it is not known whether regimens using clomiphene are at least as effective as gonadotropins alone.

OBJECTIVES

To determine whether clomiphene citrate with gonadotropins (with or without mid-cycle antagonist) is more effective than gonadotropins with gonadotropin-releasing hormone (GnRH) agonists for controlled ovarian stimulation in IVF or intracytoplasmic sperm injection (ICSI) treatment.

SEARCH METHODS

Cochrane Menstrual Disorders and Subfertility Group Trials Register (searched March 2012), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, first quarter), MEDLINE (1970 to March 2012), EMBASE (1985 to Mar 2012) and reference lists of articles. Relevant conference proceedings were handsearched.

SELECTION CRITERIA

Randomised controlled trials (RCT) were included. Live birth rate (LBR) per woman was the primary outcome.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility and quality of trials

MAIN RESULTS

Fourteen studies were included in the review. Meta-analysis could be performed with the data of 12 included studies, with a total of 2536 participants. There was no evidence that clomiphene along with gonadotropins for IVF, with or without mid-cycle GnRH antagonist, differed from gonadotropins alone in GnRH agonist protocols in terms of live births (5 RCTs, 1079 women; OR 0.93, 95% CI 0.69 to1.24) or clinical pregnancy (11 RCTs, 1864 women; OR 1.07, 95% CI 0.85 to1.33). This means that for a typical clinic with 23% LBR using a GnRH agonist regimen, switching to clomiphene protocols would be expected to result in LBRs between 16% and 26%. There was a significant reduction in the incidence of OHSS (5 RCTs, 1559 women; OR 0.23, 95% CI 0.10 to 0.52). This means that for a typical clinic with 3.5% prevalence of OHSS using a GnRH agonist regimen, switching to clomiphene citrate protocols would be expected to reduce the incidence to between 0.8% and 1.8%. The trials included in this review were very old and outcomes such as live births, multiple pregnancy, OHSS and miscarriages have not been reported by most studies.

AUTHORS' CONCLUSIONS

There was no evidence to indicate that clomiphene with gonadotropins (with or without GnRH antagonist) differed significantly from gonadotropins in GnRH agonist protocols for women undergoing IVF treatment, in terms of live births or pregnancy rates. Meanwhile, use of clomiphene led to a reduction in the incidence of OHSS. However, these results were based on data from a small number of underpowered randomised trials with few participants. Hence there was insufficient evidence to recommend use of clomiphene citrate in routine IVF practice. Larger trials with adequate power are required.

Efficacy and safety of long-acting GnRH agonists in in vitro fertilization and embryo transfer

The introduction of gonadotrophin-releasing hormone (GnRH) agonists combined with gonadotrophins is considered to be one of the most significant events in the development of in vitro fertilization and embryo transfer (IVF-ET) programmes. This article reviews the use of GnRH agonists in IVF-ET programmes and the efficacy and safety of long-acting GnRH agonists. The use of agonists results in higher clinical pregnancy rates, more supernumerary embryos for cryopreservation and allows convenient programming of oocyte recovery. There are different types of agonist and ovarian stimulation protocol available for clinical use. Recent meta-analysis of the Cochrane database has demonstrated the superiority of the long protocols over the short and ultra-short protocols for GnRH agonist use in IVF and GIFT. The depot injection offers increased clinical and patient compliance and improves efficacy of pituitary downregulation. However, compared with short-acting agonists, the depot preparations are associated with a longer period of stimulation and higher doses of gonadotrophins. To date, there is no evidence of an increased risk of pregnancy wastages or teratogenicity in human pregnancies exposed to long-acting agonists.

Cost-effective approaches to in vitro fertilization: Means to improve access

Many childless couples would like to have access to in vitro fertilization (IVF) through public-sector programs, but such programs are scant because of the high costs that IVF entails today. A solution for health departments worldwide might be to leave IVF methods requiring expensive equipment and ovarian stimulating hormones - such as human recombinant gonadotropins, plus gonadotropin-releasing hormone analogues to prevent a surge of luteinizing hormone - to the private sector. Rather, health departments could focus on methods using less equipment and no ovarian stimulating agent at all if possible. If not possible, inexpensive clomiphene citrate could be used, combined with human menopausal gonadotropin if needed. Before embryo transfer, oocyte maturation could occur in vitro or in a makeshift incubator: a tube closed, wrapped, and left in the woman's vagina for 24 h. To prevent short- and long-term costs as well as possible lifelong problems, the transfer of multiple embryos should not be performed.

Influence of hormonal stimulation on in vitro fertilization/embryo transfer outcome

OBJECTIVE

To compare efficacy and efficiency of ovarian stimulation therapy.

STUDY DESIGN

Retrospective study compares ovarian response as number of retrieved oocytes, fertilization rates, endometrial patterns, number of pregnancies and pregnancy rates to different stimulation protocols.

RESULTS

The least number of cancelled cycles was in long protocols with buserelin. There was no difference in overall number of retrieved oocytes between the rFSH and HMG protocols, but 75% of the patients undergoing both protocols had higher number of oocytes after rFSH. The highest pregnancy rate (35.13%) was with rFSH. There was no statistical correlation between endometrial pattern and type of protocol used. Data showed the 9 mm cut-off value for endometrial thickness, and RI = 0.58 for subendometrial blood flow between the pregnant and non-pregnant group of patients. Nitriderm patches significantly decreased (P < 0.05) subendometrial RI of the patients with impaired uterine perfusion, increased endometrial thickness and achieved better morphology.

CONCLUSIONS

These findings demonstrate that rFSH alone and in long protocol gives better results in wide patient population. Nitriderm patches seem to have good impact on pregnancy rate, but further studies are necessary before making any statements.