Human chorionic gonadotrophin luteal support overcomes luteal phase inadequacy after gonadotrophin-releasing hormone agonist-induced ovulation in gonadotrophin-stimulated cycles

Luteal phase support for women trying to conceive by intrauterine insemination or sexual intercourse

BACKGROUND

Ovulation induction may impact endometrial receptivity due to insufficient progesterone secretion. Low progesterone is associated with poor pregnancy outcomes.

OBJECTIVES

To assess the effectiveness and safety of luteal phase support (LPS) in infertile women trying to conceive by intrauterine insemination or by sexual intercourse.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, LILACS, trial registries for ongoing trials, and reference lists of articles (from inception to 25 August 2021).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of LPS using progestogen, human chorionic gonadotropin (hCG), or gonadotropin-releasing hormone (GnRH) agonist supplementation in IUI or natural cycle.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were live birth rate/ongoing pregnancy rate (LBR/OPR) and miscarriage.  MAIN RESULTS: We included 25 RCTs (5111 participants). Most studies were at unclear or high risk of bias. We graded the certainty of evidence as very low to low. The main limitations of the evidence were poor reporting and imprecision. 1. Progesterone supplement versus placebo or no treatment  We are uncertain if vaginal progesterone increases LBR/OPR (risk ratio (RR) 1.10, 95% confidence interval (CI) 0.81 to 1.48; 7 RCTs; 1792 participants; low-certainty evidence) or decreases miscarriage per pregnancy compared to placebo or no treatment (RR 0.70, 95% CI 0.40 to 1.25; 5 RCTs; 261 participants). There were no data on LBR or miscarriage with oral stimulation. We are uncertain if progesterone increases LBR/OPR in women with gonadotropin stimulation (RR 1.24, 95% CI 0.80 to 1.92; 4 RCTs; 1054 participants; low-certainty evidence) and oral stimulation (clomiphene citrate or letrozole) (RR 0.97, 95% CI 0.58 to 1.64; 2 RCTs; 485 participants; low-certainty evidence). One study reported on OPR in women with gonadotropin plus oral stimulation; the evidence from this study was uncertain (RR 0.73, 95% CI 0.37 to 1.42; 1 RCT; 253 participants; low-certainty evidence). Given the low certainty of the evidence, it is unclear if progesterone reduces miscarriage per clinical pregnancy in any stimulation protocol (RR 0.68, 95% CI 0.24 to 1.91; 2 RCTs; 102 participants, with gonadotropin; RR 0.67, 95% CI 0.30 to 1.50; 2 RCTs; 123 participants, with gonadotropin plus oral stimulation; and RR 0.53, 95% CI 0.25 to 1.14; 2 RCTs; 119 participants, with oral stimulation). Low-certainty evidence suggests that progesterone in all types of ovarian stimulation may increase clinical pregnancy compared to placebo (RR 1.38, 95% CI 1.10 to 1.74; 7 RCTs; 1437 participants, with gonadotropin; RR 1.40, 95% CI 1.03 to 1.90; 4 RCTs; 733 participants, with gonadotropin plus oral stimulation (clomiphene citrate or letrozole); and RR 1.44, 95% CI 1.04 to 1.98; 6 RCTs; 1073 participants, with oral stimulation). 2. Progesterone supplementation regimen  We are uncertain if there is any difference between 300 mg and 600 mg of vaginal progesterone for OPR and multiple pregnancy (RR 1.58, 95% CI 0.81 to 3.09; 1 RCT; 200 participants; very low-certainty evidence; and RR 0.50, 95% CI 0.05 to 5.43; 1 RCT; 200 participants, very low-certainty evidence, respectively). No other outcomes were reported for this comparison. There were three different comparisons between progesterone regimens. For OPR, the evidence is very uncertain for intramuscular (IM) versus vaginal progesterone (RR 0.59, 95% CI 0.34 to 1.02; 1 RCT; 225 participants; very low-certainty evidence); we are uncertain if there is any difference between oral and vaginal progesterone (RR 1.25, 95% CI 0.70 to 2.22; 1 RCT; 150 participants; very low-certainty evidence) or between subcutaneous and vaginal progesterone (RR 1.05, 95% CI 0.54 to 2.05; 1 RCT; 246 participants; very low-certainty evidence). We are uncertain if IM or oral progesterone reduces miscarriage per clinical pregnancy compared to vaginal progesterone (RR 0.75, 95% CI 0.43 to 1.32; 1 RCT; 81 participants and RR 0.58, 95% CI 0.11 to 3.09; 1 RCT; 41 participants, respectively). Clinical pregnancy and multiple pregnancy were reported for all comparisons; the evidence for these outcomes was very uncertain. Only one RCT reported adverse effects. We are uncertain if IM route increases the risk of adverse effects when compared with the vaginal route (RR 9.25, 95% CI 2.21 to 38.78; 1 RCT; 225 participants; very low-certainty evidence). 3. GnRH agonist versus placebo or no treatment  No trials reported live birth. The evidence is very uncertain about the effect of GnRH agonist in ongoing pregnancy (RR 1.10, 95% CI 0.70 to 1.74; 1 RCT; 291 participants, very low-certainty evidence), miscarriage per clinical pregnancy (RR 0.73, 95% CI 0.26 to 2.10; 2 RCTs; 79 participants, very low-certainty evidence) and clinical pregnancy (RR 1.00, 95% CI 0.68 to 1.47; 2 RCTs; 340 participants; very low-certainty evidence), and multiple pregnancy (RR 0.28, 95% CI 0.11 to 0.70; 2 RCTs; 126 participants). 4. GnRH agonist versus vaginal progesterone  The evidence for the effect of GnRH agonist injection on clinical pregnancy is very uncertain (RR 1.00, 95% CI 0.51 to 1.95; 1 RCT; 242 participants). 5. HCG injection versus no treatment  The evidence for the effect of hCG injection on clinical pregnancy (RR 0.93, 95% CI 0.40 to 2.13; 1 RCT; 130 participants) and multiple pregnancy rates (RR 1.03, 95% CI 0.22 to 4.92; 1 RCT; 130 participants) is very uncertain. 6. Luteal support in natural cycle No study evaluated the effect of LPS in natural cycle. We could not perform sensitivity analyses, as there were no studies at low risk of selection bias and not at high risk in other domains.

AUTHORS' CONCLUSIONS

We are uncertain if vaginal progesterone supplementation during luteal phase is associated with a higher live birth/ongoing pregnancy rate. Vaginal progesterone may increase clinical pregnancy rate; however, its effect on miscarriage rate and multiple pregnancy rate is uncertain. We are uncertain if IM progesterone improves ongoing pregnancy rates or decreases miscarriage rate when compared to vaginal progesterone. Regarding the other reported comparisons, neither oral progesterone nor any other medication appears to be associated with an improvement in pregnancy outcomes (very low-certainty evidence).

Individualized luteal phase support after fresh embryo transfer: unanswered questions, a review

Background

Luteal phase support (LPS) is an important part of assisted reproductive technology (ART), and adequate LPS is crucial for embryo implantation. At present, a great number of studies have put emphasis on an individualized approach to controlled ovarian stimulation (COS) and endometrium preparation of frozen- thawed embryo transfer (FET); However, not much attention has been devoted to the luteal phase and almost all ART cycles used similar LPS protocol bases on experience.

Main body

This review aims to concisely summarize individualized LPS protocols in fresh embryo transfer cycles with hCG trigger or GnRH-a trigger. The PubMed and Google Scholar databases were searched using the keywords: (luteal phase support or LPS) AND (assisted reproductive technology or ART or in vitro fertilization or IVF). We performed comprehensive literature searches in the English language describing the luteal phase support after ART, since 1978 and ending in May 2019. Recent studies have shown that many modified LPS programs were used in ART cycle. In the cycle using hCG for final oocyte maturation, the progesterone with or without low dose of hCG may be adequate to maintain pregnancy. In the cycle using GnRH-a for trigger, individualized low dose of hCG administration with or without progesterone was suggested. The optimal timing to start the LPS would be between 24 and 72 h after oocyte retrieval and should last at least until the pregnancy test is positive. Addition of E₂ and the routes of progesterone administration bring no beneficial effect on the outcomes after ART.

Conclusions

Individualized LPS should be applied, according to the treatment protocol, the patients’ specific characteristics, and desires.

Luteal phase support (LPS) is an important part of assisted reproductive technology (ART). In the cycle using hCG for final oocyte maturation, the progesterone with or without low dose of hCG may be adequate to maintain pregnancy. In the cycle using GnRH-a for trigger, individualized low dose of hCG administration with or without progesterone was suggested. The optimal timing to start the LPS would be between 24 and 72 h after oocyte retrieval and should last at least until the pregnancy test is positive. Addition of E₂ and the routes of progesterone administration bring no beneficial effect on the outcomes after ART. Individualized LPS should be applied, according to the treatment protocol, the patients’ specific characteristics, and desires.

Gonadotropin-releasing hormone agonist for ovulation trigger - OHSS prevention and use of modified luteal phase support for fresh embryo transfer

The introduction of gonadotrophin-releasing hormone agonist (GnRHa) trigger greatly impacted modern IVF treatment. Patients at low risk of ovarian hyperstimulation syndrome (OHSS) development, undergoing fresh embryo transfer and GnRHa trigger can be offered a virtually OHSS-free treatment with non-inferior reproductive outcomes by using a modified luteal phase support in terms of small boluses of human chorionic gonadotrophin (hCG), daily recombinant luteinizing hormone LH (rLH) or GnRHa. In the OHSS risk patient, GnRHa trigger can safely be performed, followed by a 'freeze-all' policy with a minimal risk of OHSS development and high live birth rates in the subsequent frozen embryo transfer cycle. Importantly, GnRHa trigger opened the 'black box' of the luteal phase, promoting research in the most optimal steroid levels during the luteal phase. GnRHa trigger allows high-dose gonadotropin stimulation to achieve the optimal number of oocytes and embryos needed to ensure the highest chance of live birth. This review thoroughly discusses how the GnRHa trigger concept adds safety and efficacy to modern IVF in terms of OHSS prevention. Furthermore, the optimal luteal phase management after GnRHa trigger in fresh embryo transfer cycles is discussed.

The role of luteal support during IVF: a qualitative systematic review

The aim of this review is to provide qualitative evidence-based synthesis regarding efficacy of luteal-phase support on fertility outcome in women undergoing in vitro fertilization (IVF) with respect to clinical or live birth rates and pregnancy loss rates. Although the need of luteal phase support in IVF/ICSI cycles is well-known, the optimal start, dosage, route and the duration of the luteal phase support is still subject of debate. Data suggest that the optimal period to start with the luteal phase support would be between 24-72 hours after oocyte-retrieval and should continue at least until a positive pregnancy test is achieved. However, the majority of IVF-centers worldwide provide progesterone support up to 8 weeks of pregnancy. Among the well-established routes of luteal support, oral dydrogesterone and subcutaneous progesterone represent new and interesting routes of progesterone administration. The current studies support these routes of progesterone administration use in terms of comparable pregnancy rates and pregnancy loss rates to vaginal and intramuscular progesterone. Furthermore, the acceptance and tolerability among patients seems to be even better. In the frozen-thawed embryo transfer, dydrogesterone and vaginal progesterone are not effective as monotherapy treatments; however, when combined there is no reason to avoid one or the other in this setting.

Gonadotropin-releasing hormone agonist versus HCG for oocyte triggering in antagonist-assisted reproductive technology

BACKGROUND

Human chorionic gonadotropin (HCG) is routinely used for final oocyte maturation triggering in in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) cycles, but the use of HCG for this purpose may have drawbacks. Gonadotropin-releasing hormone (GnRH) agonists present an alternative to HCG in controlled ovarian hyperstimulation (COH) treatment regimens in which the cycle has been down-regulated with a GnRH antagonist. This is an update of a review first published in 2010.

OBJECTIVES

To evaluate the effectiveness and safety of GnRH agonists in comparison with HCG for triggering final oocyte maturation in IVF and ICSI for women undergoing COH in a GnRH antagonist protocol.

SEARCH METHODS

We searched databases including the Menstrual Disorders and Subfertility Group (MDSG) Specialised Register of Controlled Trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, the Cumulative Index to Nursing and Allied Health Literature (CINAHL) and trial registers for published and unpublished articles (in any language) on randomised controlled trials (RCTs) of gonadotropin-releasing hormone agonists versus HCG for oocyte triggering in GnRH antagonist IVF/ICSI treatment cycles. The search is current to 8 September 2014.

SELECTION CRITERIA

RCTs that compared the clinical outcomes of GnRH agonist triggers versus HCG for final oocyte maturation triggering in women undergoing GnRH antagonist IVF/ICSI treatment cycles were included.

DATA COLLECTION AND ANALYSIS

Two or more review authors independently selected studies, extracted data and assessed study risk of bias. Treatment effects were summarised using a fixed-effect model, and subgroup analyses were conducted to explore potential sources of heterogeneity. Treatment effects were expressed as mean differences (MDs) for continuous outcomes and as odds ratios (ORs) for dichotomous outcomes, together with 95% confidence intervals (CIs). Primary outcomes were live birth and rate of ovarian hyperstimulation syndrome (OHSS) per women randomised. Grades of Recommendation, Assessment, Development and Evaluation (GRADE) methods were used to assess the quality of the evidence for each comparison.

MAIN RESULTS

We included 17 RCTs (n = 1847), of which 13 studies assessed fresh autologous cycles and four studies assessed donor-recipient cycles. In fresh autologous cycles, GnRH agonists were associated with a lower live birth rate than was seen with HCG (OR 0.47, 95% CI 0.31 to 0.70; five RCTs, 532 women, I(2) = 56%, moderate-quality evidence). This suggests that for a woman with a 31% chance of achieving live birth with the use of HCG, the chance of a live birth with the use of an GnRH agonist would be between 12% and 24%.In women undergoing fresh autologous cycles, GnRH agonists were associated with a lower incidence of mild, moderate or severe OHSS than was HCG (OR 0.15, 95% CI 0.05 to 0.47; eight RCTs, 989 women, I² = 42%, moderate-quality evidence). This suggests that for a woman with a 5% risk of mild, moderate or severe OHSS with the use of HCG, the risk of OHSS with the use of a GnRH agonist would be between nil and 2%.In women undergoing fresh autologous cycles, GnRH agonists were associated with a lower ongoing pregnancy rate than was seen with HCG (OR 0.70, 95% CI 0.54 to 0.91; 11 studies, 1198 women, I(2) = 59%, low-quality evidence) and a higher early miscarriage rate (OR 1.74, 95% CI 1.10 to 2.75; 11 RCTs, 1198 women, I² = 1%, moderate-quality evidence). However, the effect was dependent on the type of luteal phase support provided (with or without luteinising hormone (LH) activity); the higher rate of pregnancies in the HCG group applied only to the group that received luteal phase support without LH activity (OR 0.36, 95% CI 0.21 to 0.62; I(2) = 73%, five RCTs, 370 women). No evidence was found of a difference between groups in risk of multiple pregnancy (OR 3.00, 95% CI 0.30 to 30.47; two RCTs, 62 women, I(2) = 0%, low-quality evidence).In women with donor-recipient cycles, no evidence suggested a difference between groups in live birth rate (OR 0.92, 95% CI 0.53 to 1.61; one RCT, 212 women) or ongoing pregnancy rate (OR 0.88, 95% CI 0.58 to 1.32; three RCTs, 372 women, I² = 0%). We found evidence of a lower incidence of OHSS in the GnRH agonist group than in the HCG group (OR 0.05, 95% CI 0.01 to 0.28; three RCTs, 374 women, I² = 0%).The main limitation in the quality of the evidence was risk of bias associated with poor reporting of methods in the included studies.

AUTHORS' CONCLUSIONS

Final oocyte maturation triggering with GnRH agonist instead of HCG in fresh autologous GnRH antagonist IVF/ICSI treatment cycles prevents OHSS to the detriment of the live birth rate. In donor-recipient cycles, use of GnRH agonists instead of HCG resulted in a lower incidence of OHSS, with no evidence of a difference in live birth rate.Evidence suggests that GnRH agonist as a final oocyte maturation trigger in fresh autologous cycles is associated with a lower live birth rate, a lower ongoing pregnancy rate (pregnancy beyond 12 weeks) and a higher rate of early miscarriage (less than 12 weeks). GnRH agonist as an oocyte maturation trigger could be useful for women who choose to avoid fresh transfers (for whatever reason), women who donate oocytes to recipients or women who wish to freeze their eggs for later use in the context of fertility preservation.

Assisted reproductive techniques

Assisted reproductive technologies (ART) encompass fertility treatments, which involve manipulations of both oocyte and sperm in vitro. This chapter provides a brief overview of ART, including indications for treatment, ovarian reserve testing, selection of controlled ovarian hyperstimulation (COH) protocols, laboratory techniques of ART including in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI), embryo transfer techniques, and luteal phase support. This chapter also discusses potential complications of ART, namely ovarian hyperstimulation syndrome (OHSS) and multiple gestations, and the perinatal outcomes of ART.

The luteal phase after ovarian stimulation

Evaluation of the luteal phase after ovarian stimulation presents several difficulties. Until today, it has not been proved that in cycles stimulated with clomiphene citrate/human menopausal gonadotrophins, luteal supplementation with progesterone significantly increases implantation rate. On the contrary, it is accepted that in cycles stimulated with GnRH agonists/gonadotrophins, support of the luteal phase is essential for the achievement of pregnancy. In GnRH antagonist cycles luteal supplementation, although widely practised, is not at present supported by randomized controlled trials. Finally, it appears that the combination of gonadotrophin stimulation with human chorionic gonadotrophin results in an inadequate luteal phase with or without the use of either agonists or antagonists.

GnRH agonist for triggering of final oocyte maturation: time for a change of practice?

BACKGROUND

GnRH agonist (GnRHa) triggering has been shown to significantly reduce the occurrence of ovarian hyperstimulation syndrome (OHSS) compared with hCG triggering; however, initially a poor reproductive outcome was reported after GnRHa triggering, due to an apparently uncorrectable luteal phase deficiency. Therefore, the challenge has been to rescue the luteal phase. Studies now report a luteal phase rescue, with a reproductive outcome comparable to that seen after hCG triggering.

METHODS

This narrative review is based on expert presentations and subsequent group discussions supplemented with publications from literature searches and the authors' knowledge. Moreover, randomized controlled trials (RCTs) were identified and analysed either in fresh IVF cycles with embryo transfer (ET), oocyte donation cycles or cycles without ET; risk differences were calculated regarding pregnancy rate and OHSS rate.

RESULTS

In fresh IVF cycles with ET (9 RCTs) no OHSS was reported after GnRHa triggering [0% incidence in the GnRHa group: risk difference 5% (with 95% CI: -0.07 to 0.02)]. Importantly, the delivery rate improved significantly after modified luteal support [6% risk difference in favour of the HCG group (95% CI: -0.14 to 0.2)] when compared with initial studies with conventional luteal support [18% risk difference (95% CI: -0.36 to 0.01)]. In oocyte donation cycles (4 RCTs) the OHSS incidence is 0% [10% risk difference (95% CI: 0.02-0.40)].

CONCLUSIONS

GnRHa triggering is a valid alternative to hCG triggering, resulting in an elimination of OHSS. After modified luteal support there is now a non-significant difference of 6% in delivery rate in favour of hCG triggering.

Gonadotropin-releasing hormone agonist versus HCG for oocyte triggering in antagonist assisted reproductive technology cycles

BACKGROUND

Gonadotropin-releasing hormone (GnRH) antagonist protocols for pituitary down regulation in in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) allow the use of GnRH agonists for triggering final oocyte maturation. Currently, human chorionic gonadotropin (HCG) is still the standard medication for this purpose. The effectiveness of triggering with a GnRH agonist compared to HCG measured as pregnancy and ovarian hyperstimulation(OHSS) rates are unknown.

OBJECTIVES

To compare the effectiveness of a GnRH agonist with HCG for triggering final oocyte maturation in IVF and ICSI patients undergoing controlled ovarian hyperstimulation in a GnRH antagonist protocol followed by embryo transfer. 

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE , EMBASE, the National Research Register, the Medical Research Council's Clinical Trials Register, and the NHS Centre for Reviews and Dissemination database. We also examined the reference lists of all known primary studies and review articles, citation lists of relevant publications and abstracts of major scientific meetings.

SELECTION CRITERIA

All randomised controlled studies (RCTs) reporting data comparing clinical outcomes for women undergoing IVF and ICSI cycles and using a GnRH agonist in comparison with HCG for final oocyte maturation triggering.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

We identified 11 RCTs (n = 1055). Eight studies assessed fresh autologous cycles and three studies assessed donor-recipient cycles. In fresh-autologous cycles, GnRH agonist was less effective than HCG in terms of the live birth rate per randomised woman (OR 0.44, 95% CI 0.29 to 0.68; 4 RCTs) and ongoing pregnancy rate per randomised woman (OR 0.45, 95% CI 0.31 to 0.65; 8 RCTs). For a group with a 30% live birth or ongoing pregnancy rate using HCG, the rate would be between 12% and 22% using an GnRH agonist. Moderate to severe ovarian hyperstimulation syndrome (OHSS) incidence per randomised woman was significantly lower in the GnRH agonist group compared to the HCG group (OR 0.10, 95% CI 0.01 to 0.82; 5 RCTs). For a group with a 3% OHSS rate using HCG the rate would be between 0% and 2.6% using GnRH agonist. In donor recipient cycles, there was no evidence of a statistical difference in the live birth rate per randomised woman (OR 0.92, 95% CI 0.53 to 1.61; 1 RCT).

AUTHORS' CONCLUSIONS

We do not recommend that GnRH agonists be routinely used as a final oocyte maturation trigger in fresh autologous cycles because of lowered live birth rates and ongoing pregnancy rates. An exception could be made for women with high risk of OHSS, after appropriate counselling.

Gonadotropin-releasing hormone agonist versus HCG for oocyte triggering in antagonist assisted reproductive technology cycles

BACKGROUND

Gonadotropin-releasing hormone (GnRH) antagonist protocols for pituitary down regulation in in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) allow the use of GnRH agonists for triggering final oocyte maturation. Currently, human chorionic gonadotropin (HCG) is still the standard medication for this purpose. The effectiveness of triggering with a GnRH agonist compared to HCG measured as pregnancy and ovarian hyperstimulation(OHSS) rates are unknown.

OBJECTIVES

To compare the effectiveness of a GnRH agonist with HCG for triggering final oocyte maturation in IVF and ICSI patients undergoing controlled ovarian hyperstimulation in a GnRH antagonist protocol followed by embryo transfer. 

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE , EMBASE, the National Research Register, the Medical Research Council's Clinical Trials Register, and the NHS Centre for Reviews and Dissemination database. We also examined the reference lists of all known primary studies and review articles, citation lists of relevant publications and abstracts of major scientific meetings.

SELECTION CRITERIA

All randomised controlled studies (RCTs) reporting data comparing clinical outcomes for women undergoing IVF and ICSI cycles and using a GnRH agonist in comparison with HCG for final oocyte maturation triggering.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

We identified 11 RCTs (n = 1055). Eight studies assessed fresh autologous cycles and three studies assessed donor-recipient cycles. In fresh-autologous cycles, GnRH agonist was less effective than HCG in terms of the live birth rate per randomised woman (OR 0.44, 95% CI 0.29 to 0.68; 4 RCTs) and ongoing pregnancy rate per randomised woman (OR 0.45, 95% CI 0.31 to 0.65; 8 RCTs). For a group with a 30% live birth or ongoing pregnancy rate using HCG, the rate would be between 12% and 22% using an GnRH agonist. Moderate to severe ovarian hyperstimulation syndrome (OHSS) incidence per randomised woman was significantly lower in the GnRH agonist group compared to the HCG group (OR 0.10, 95% CI 0.01 to 0.82; 5 RCTs). For a group with a 3% OHSS rate using HCG the rate would be between 0% and 2.6% using GnRH agonist. In donor recipient cycles, there was no evidence of a statistical difference in the live birth rate per randomised woman (OR 0.92, 95% CI 0.53 to 1.61; 1 RCT).

AUTHORS' CONCLUSIONS

We do not recommend that GnRH agonists be routinely used as a final oocyte maturation trigger in fresh autologous cycles because of lowered live birth rates and ongoing pregnancy rates. An exception could be made for women with high risk of OHSS, after appropriate counselling.

1,500 IU human chorionic gonadotropin administered at oocyte retrieval rescues the luteal phase when gonadotropin-releasing hormone agonist is used for ovulation induction: a prospective, randomized, controlled study

OBJECTIVE

To prospectively assess the reproductive outcome with a small bolus of hCG administered on the day of oocyte retrieval after ovulation induction with a GnRH agonist (GnRHa).

DESIGN

Prospective, randomized trial.

SETTING

Three hospital-based IVF clinics.

PATIENT(S)

Three hundred five IVF/intracytoplasmic sperm injection patients after a GnRH antagonist protocol.

INTERVENTION(S)

Ovulation induction was performed with either 10,000 IU hCG or 0.5 mg GnRHa (buserelin) supplemented with 1,500 IU hCG on the day of oocyte retrieval.

MAIN OUTCOME MEASURE(S)

Reproductive outcome in the two groups.

RESULT(S)

No significant differences were seen regarding positive hCG/ET rate (48% and 48%), ongoing pregnancy rate (26% and 33%), delivery rate (24% and 31%), and rate of early pregnancy loss (21% and 17%) between the GnRHa and 10,000 IU hCG groups, respectively.

CONCLUSION(S)

A small bolus of hCG in the GnRHa group secured the luteal phase, resulting in a comparable reproductive outcome in the two groups. However, a nonsignificant difference of 7% in delivery rates justifies further studies to refine the use of GnRHa for ovulation induction.

Effects of gonadotropin-releasing hormone agonists and antagonists on luteal function

PURPOSE OF REVIEW

This review addresses the effects of gonadotropin-releasing hormone agonists and antagonists on various aspects of the luteal phase.

RECENT FINDINGS

Recent studies have shown that use of both gonadotropin-releasing hormone agonists and antagonists during in-vitro fertilization cycles leads to alterations in the hormonal profiles of the luteal phase as well as changes in endometrial histology. Gonadotropin-releasing hormone agonists are effective in triggering final oocyte maturation and reducing the incidence of ovarian hyperstimulation syndrome. Ongoing pregnancy rates are excellent after gonadotropin-releasing hormone agonist trigger when luteal phase and early pregnancy supplementation with estradiol and progesterone is provided. Gonadotropin-releasing hormone agonists have recently been used for luteal phase support in in-vitro fertilization cycles.

SUMMARY

Although gonadotropin-releasing hormone agonists and antagonists are clinically useful, they may have adverse effects on luteal function. Luteal phase supplementation significantly improves clinical outcomes in in-vitro fertilization cycles because it may correct some of these detrimental effects. Use of gonadotropin-releasing hormone agonist to induce oocyte maturation is beneficial to patients who are at increased risk for ovarian hyperstimulation syndrome. The key factor in achieving favorable ongoing pregnancy rates with use of gonadotropin-releasing hormone agonist to induce oocyte maturation appears to be adequate luteal phase support.

GnRH agonist Lupron® (leuprolide acetate) pre-treatments prevent ovulation in response to gonadotropin stimulation in the clouded leopard (Neofelis nebulosa)

In many species, controlling the ovary prior to induction of ovulation improves the success of ovarian response and artificial insemination (AI). We assessed the impact of suppression of estrus with the GnRH agonist, Lupron, on ovarian sensitivity to equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) in the clouded leopard. Seven female clouded leopards were given two injections of Lupron (3.75 mg IM) 23 d apart, followed 44 d later by eCG and hCG. Daily fecal samples were collected from 60 d before Lupron to 60 d after hCG. Fecal metabolites of estrogen (E) and progesterone (P) were measured by radioimmunoassay. Lupron decreased (P < 0.05) the number of E peaks during Lupron treatment compared to pre-Lupron. All females had baseline E and six of seven (86%) had nadir P on day of eCG. Exogenous gonadotropins induced E elevations in all females. However, mean E in the gonadotropin-provoked estrus was decreased (P < 0.05) compared to pre-Lupron estrous periods. Only one of seven (14%) females ovulated after eCG/hCG. In conclusion, estrous cycle control with Lupron resulted in predictable ovarian suppression prior to gonadotropin stimulation but altered ovarian sensitivity by an as yet unknown mechanism so that ovulation was inhibited, even when using a proven exogenous gonadotropin protocol.

Safety and efficacy of low dose hCG for luteal support after triggering ovulation with a GnRH agonist in cases of polyfollicular development

OBJECTIVE

The use of GnRH agonists instead of hCG to trigger ovulation seems to be an effective way to prevent subsequent hCG induced ovarian hyperstimulation in cases of polyfollicular development. But conflicting results are reported on the efficiency of subsequent luteal support using hCG and/or progesterone supplementation.

STUDY DESIGN

We investigated the efficiency and safety of different luteal support regimes in low dose gonadotropin stimulation non-ivf cycles. A risk for an imminent ovarian hyperstimulation was assumed if preovulatory estradiol levels rose up higher than 700 pg/ml and more than 12 intermediate sized follicles (8-14 mm) were observed. Thirty-six women received 0.5mg Triptorelin subcutaneously to trigger the ovulation inducing LH surge. After randomization, luteal support regimes started on day 2 after the Triptorelin administration with injections every second day five times in all. Group (a) received 5 x 1000 IU hCG, group (b) received 5 x 500 IU hCG, and group (c) received 5 x 250 mg progesterone, intramuscularly. The monitoring of the ovulation period and the subsequent luteal phase included sonographic measurement of ovarian diameter and estimation of LH, FSH, estradiol and progesterone levels 10 and 34 h as well as 8 days after Triptorelin administration.

RESULTS

We could prove ovulation in all women and did not find symptoms of ovarian hyperstimulation in any case. Midluteal controls showed extremely low gonadotropins in all groups indicating a long lasting pituitary down regulation after one injection of 0.5 mg Triptorelin. We found high normal sex steroid levels in both hCG groups. The progesterone group displayed a marked luteal phase defect with low levels of progesterone and estradiol in all cases.

CONCLUSION

The use of GnRH agonist in cases of polyfollicular development is capable to induce ovulation without a subsequent ovarian enlargement and/or any sign of hyperstimulation syndrome. Luteal support by low dose hCG does not counteract the benefit of GnRH agonist in preventing an ovarian hyperstimulation syndrome, but seems to remedy at least in part the possible deleterious effects of GnRH agonists on luteal functionality.

Rescue of corpus luteum function with peri-ovulatory HCG supplementation in IVF/ICSI GnRH antagonist cycles in which ovulation was triggered with a GnRH agonist: a pilot study

Previous studies found a poor clinical outcome when a GnRH agonist (GnRHa) was used to trigger ovulation in GnRH antagonist IVF/ICSI cycles. This study aimed to determine the clinical and endocrine effects as well the optimal timing of HCG supplementation. Forty-five normogonadotrophic IVF/ICSI patients following a flexible antagonist protocol were prospectively randomized (sealed envelopes) to triggering of ovulation with a single bolus of either 10,000 IU of HCG (group 1, n = 15) or 0.5 mg buserelin s.c. In addition, the GnRHa triggered group was randomized into two groups: group 2 (n = 17) was supplemented with HCG 1500 IU, 12 h after ovulation induction and group 3 (n = 13) was supplemented with HCG 1500 IU 35 h after ovulation induction. Group 1 and group 3 had significantly higher luteal phase concentrations of progesterone (P < 0.001) as compared with group 2. Moreover, the clinical pregnancy rate of groups 1 and 3 was similar and significantly higher (P < 0.02) than that of group 2. A larger study, however, is required to substantiate these differences. No differences were seen regarding mid-luteal inhibin A concentrations between the three groups. Triggering of ovulation with GnRHa supplemented with 1500 IU HCG 35 h later (group 3) seems to secure a normal luteal phase and a normal clinical pregnancy outcome.

Luteal phase support in assisted reproductive technology

PURPOSE OF REVIEW

The purpose of this review is to discuss luteal support in assisted reproduction and to provide an evidence-based overview of the current options available.

RECENT FINDINGS

The luteal phase has been found to be defective in virtually all of the stimulation protocols used for in-vitro fertilization. Common mechanisms such as supraphysiological levels of estradiol, decreased output of luteinizing hormone, inhibition of the corpus luteum and asynchronization of estradiol and progesterone may be involved in insufficient function of the corpus luteum in assisted reproductive technology.

SUMMARY

Gonadotropin releasing hormone agonist undoubtedly provides benefits in stimulated cycles, however it also has adverse effects, inhibition of the corpus luteum together with supraphysiological hormonal profiles finally leading to luteal phase defects. Luteal phase support with human chorionic gonadotropin or progesterone after assisted reproduction results in increased pregnancy rates. The role of luteal phase support in these cycles has also been recently elucidated. Use of human chorionic gonadotropin for luteal phase support is associated with a marked increase in the risk of ovarian hyperstimulation syndrome, therefore progesterone is the preferred choice. Data on the benefits of estrogen supplementation are conflicting. Among the routes of progesterone administration, reductions in pregnancy rates are noted on oral administration. In spite of a lack of statistical significance, the intramuscular route seems to be more beneficial than the vaginal route when considering rates of ongoing pregnancy and live birth. Further clarification is needed on the ideal dose, the optimal route and the duration of progesterone administration in assisted reproduction.

GnRH agonist (buserelin) or hCG for ovulation induction in GnRH antagonist IVF/ICSI cycles: a prospective randomized study

BACKGROUND

We aimed to determine the efficacy of ovarian hyperstimulation protocols employing a GnRH antagonist to prevent a premature LH rise allowing final oocyte maturation and ovulation to be induced by a single bolus of either a GnRH agonist or hCG.

METHODS

A total of 122 normogonadotrophic patients following a flexible antagonist protocol was stimulated with recombinant human FSH and prospectively randomized (sealed envelopes) to ovulation induction with a single bolus of either 0.5 mg buserelin s.c. (n = 55) or 10,000 IU of hCG (n = 67). A maximum of two embryos was transferred. Luteal support consisted of micronized progesterone vaginally, 90 mg a day, and estradiol, 4 mg a day per os.

RESULTS

Ovulation was induced with GnRH agonist in 55 patients and hCG in 67 patients. Significantly more metaphase II (MII) oocytes were retrieved in the GnRH agonist group (P < 0.02). Significantly higher levels of LH and FSH (P < 0.001) and significantly lower levels of progesterone and estradiol (P < 0.001) were seen in the GnRH agonist group during the luteal phase. The implantation rate, 33/97 versus 3/89 (P < 0.001), clinical pregnancy rate, 36 versus 6% (P = 0.002), and rate of early pregnancy loss, 4% versus 79% (P = 0.005), were significantly in favour of hCG.

CONCLUSIONS

Ovulation induction with a GnRH agonist resulted in significantly more MII oocytes. However, a significantly lower implantation rate and clinical pregnancy rate in addition to a significantly higher rate of early pregnancy loss was seen in the GnRH agonist group, most probably due to a luteal phase deficiency.

Luteal phase defects following agonist-triggered ovulation: a patient-dependent response

The luteal phase (LP) of patients receiving triptorelin 0.1 mg to trigger ovulation was studied. Patients not pregnant in the first cycle with 0.1 mg were randomized into different groups for a second cycle: 0.1 mg again for patients who experienced a normal LP (group 1); patients affected with LP disorders were randomized into the following groups: 0.1 mg again (group 2); increasing dosage of triptorelin 0.5 mg once (group 3) or 0.1 mg three times (group 4); luteal support either with oral micronized progesterone (group 5) or human chorionic gonadotrophin (HCG) 1500 IU (group 6). Ovulation occurred in all cycles, but an inadequate LP was observed in 34.4% of the non-conceptional cycles. Patients demonstrating a normal LP as well as those affected with luteal disorders in their first cycle showed the same luteal pattern in their consecutive cycles triggered in the same way. In defective LP patients, increasing or repeating triptorelin doses did not restore the luteal phase or the pregnancy rate, both returning closer to normal after luteal support. Defective LP observed after agonist-triggered ovulation do not occur at random; therefore this patient-dependent response may be related to the personal characteristics of each patient's pre-ovulatory physiological surge profile.