Modulation of folliculogenesis and steroidogenesis in women by graded menotrophin administration

Highly purified hMG versus recombinant FSH in ovarian hyperstimulation with GnRH antagonists--a randomized study

BACKGROUND

Highly purified hMG (hp-hMG) has recently shown better cycle outcome than the recombinant FSH (rFSH) when compared in GnRH agonist long protocol cycles. However, they have not yet been compared in GnRH antagonist cycles.

METHODS

A RCT comparing the ongoing pregnancy rate (primary end-point) in 280 patients undergoing IVF/ICSI after stimulation with hp-hMG or rFSH controlled with a GnRH antagonist.

RESULTS

No significant differences were observed between hp-hMG and rFSH in terms of the ongoing pregnancy rate per started cycle (35.0 versus 32.1%, respectively; P = 0.61); relative risk: 1.09 (95% confidence interval: 0.78-1.51; risk difference: 2.9%). No differences were observed for implantation, clinical pregnancy and pregnancy loss rates. More oocytes were obtained from patients receiving rFSH then hMG (14.4 +/- 8.1 versus 11.3 +/- 6.0, respectively; P = 0.001). Estradiol was higher at the end of stimulation in the hp-hMG group (P = 0.02), whereas progesterone was higher in patients stimulated with rFSH (P < 0.001).

CONCLUSIONS

A similar outcome was observed for hp-hMG and rFSH when used for stimulation in GnRH antagonist cycles. However, some differences were found in ovarian response in terms of oocyte yield and hormonal profile. Clinical Trials.gov

TRIAL REGISTRATION NUMBER

NCT00669786.

Effectiveness of highly purified human menopausal gonadotropin vs. recombinant follicle-stimulating hormone in first-cycle in vitro fertilization–intracytoplasmic sperm injection patients

OBJECTIVE

To compare the effectiveness of highly purified hMG with recombinant FSH (rFSH) in IVF-intracytoplasmic sperm injection patients who were treated with a GnRH agonist.

DESIGN

An open-label, prospective, randomized comparison of fixed gonadotropin regimens.

SETTING

Eighteen Dutch IVF centers.

PATIENT(S)

Six hundred twenty-nine patients who were selected for IVF-intracytoplasmic sperm injection.

INTERVENTION(S)

Patients were randomized to receive either highly purified hMG or rFSH in a fixed dosage of 150 IU/d after GnRH-agonist suppression (long protocol).

MAIN OUTCOME MEASURE(S)

Ongoing pregnancy rate per started cycle. Difference between the two treatment groups was tested by using odds ratios, including the 95% confidence limits (intention-to-treat sample), and by using the Fisher's exact test (per-protocol sample).

RESULT(S)

The ongoing pregnancy rates per started cycle were 26.3% and 25.2% for highly purified hMG and rFSH, respectively (no statistically significant difference). Treatment with highly purified hMG resulted in statistically significantly fewer oocytes (n = 7.8) than did treatment with rFSH (n = 10.6). There were no differences with respect to fertilization rates and implantation rates. Cycles with highly purified hMG were statistically significantly less often canceled as a result of ovarian hyperresponse (2.0% vs. 6.0% for highly purified hMG and rFSH, respectively).

CONCLUSION(S)

Compared with rFSH, highly purified hMG did not result in superiority in ongoing pregnancy rates in first-cycle IVF-intracytoplasmic sperm injection patients who were treated with a fixed dosage of 150 IU of gonadotropin per day. Compared with rFSH, treatment with highly purified hMG resulted in retrieval of fewer oocytes, a lower incidence of hyperresponse, and comparable pregnancy rates.

Insulin and insulin-like growth factor stimulation of vascular endothelial growth factor production by luteinized granulosa cells: comparison between polycystic ovarian syndrome (PCOS) and non-PCOS women

CONTEXT

Vascular endothelial growth factor A (VEGF-A) is a potent cytokine that promotes angiogenesis and vascular permeability. After controlled ovarian stimulation (COS) for in vitro fertilization (IVF), excessive VEGF-A production can occur, particularly in women with polycystic ovarian syndrome (PCOS); however, it is unclear whether the regulation of VEGF-A production is different between PCOS and non-PCOS women.

OBJECTIVE

The aim of this study was to determine whether there were differences in the dose- and time-dependent effects of insulin and IGFs on VEGF-A production by luteinized granulosa cells (LGCs) from women with and without PCOS.

DESIGN AND SETTING

A prospective comparative experimental study was conducted at an institutional practice.

PATIENTS

Patients included six PCOS and six non-PCOS women undergoing COS and IVF.

INTERVENTIONS

Interventions included COS for IVF.

MAIN OUTCOME MEASURES

VEGF-A levels in culture media were collected daily for 3 d from LGCs after incubation with variable doses of insulin, IGF-I, and IGF-II in the presence and absence of LH.

RESULTS

In both study groups, exposure to LH alone did not alter VEGF-A levels. However, insulin or IGF increased VEGF-A levels within 1 d and appeared to synergize with LH at 3 d. VEGF-A production by non-PCOS LGCs was more sensitive to IGF exposure, whereas PCOS cells were more sensitive to insulin. Although an increase in DNA content (P < 0.05) was noted in cultures of PCOS cells, progesterone levels were lower compared with non-PCOS LGCs.

CONCLUSION

Insulin and IGFs promote VEGF-A production in LGCs, but the response patterns are different when cells from PCOS and non-PCOS women are compared.

Clinical effects of ovulation induction with recombinant follicle-stimulating hormone supplemented with recombinant luteinizing hormone or low-dose recombinant human chorionic gonadotropin in the midfollicular phase in microdose cycles in poor responders

OBJECTIVE

To assess the clinical effects of recombinant luteinizing hormone (LH) or low-dose recombinant human chorionic gonadotropin (hCG) supplementation administered in the midfollicular phase in microdose gonadotropin-releasing hormone analogue (GnRH-a) flare-up cycles.

DESIGN

Prospective randomized study.

SETTING

Private infertility clinic.

PATIENT(S)

A total of 170 women enrolled, with 145 women eligible for randomization.

INTERVENTION(S)

After randomization, 51 patients (group A) received only 600 IU of recombinant follicle-stimulating hormone (FSH) as the control group, 46 patients (group B) received 600 IU of recombinant FSH plus daily supplementation with 75 IU of recombinant luteinizing hormone, and 48 patients (group C) received 600 IU of recombinant FSH plus daily supplementation with 75 IU of recombinant hCG.

MAIN OUTCOME MEASURE(S)

Peak estradiol (E(2)) levels, days of stimulation with recombinant FSH, total recombinant FSH dosage, metaphase II oocytes retrieved, pregnancy rate (positive hCG levels), clinical pregnancy rate (positive fetal cardiac activity), and cancellation rates of stimulation and embryo transfer.

RESULT(S)

The pregnancy rates were 35.1%, 27.6% and 31.2% for groups A, B, and C, respectively. Clinical pregnancy rates were 27.1%, 27.5, and 21.8% for groups A, B, and C, respectively. There were no statistically significant differences in the age, peak serum E(2) concentration, total recombinant FSH dosage, days of stimulation with recombinant FSH, total number of metaphase II oocytes retrieved, number of embryos transferred, pregnancy rates, clinical pregnancy rates, or cancellation rates of stimulation and embryo transfer among the three groups.

CONCLUSION(S)

Additional exogenous LH activity in the form of either recombinant luteinizing hormone or low-dose recombinant hCG is unnecessary in microdose cycles to increase pregnancy rates.

Ovarian stimulation with daily late follicular phase administration of low-dose human chorionic gonadotropin for in vitro fertilization: a prospective, randomized trial

OBJECTIVE

Evaluate the effectiveness of a new ovarian stimulation (OS) protocol before IVF.

DESIGN

Prospective clinical randomized trial.

SETTING

Private centers.

PATIENT(S)

Three hundred and twenty-three intended-to-treat women candidates for IVF.

INTERVENTION(S)

Patients were divided into three groups and administered the following treatments: group A, recombinant hFSH from day 3 until follicles reached 13-14 mm, when recombinant hFSH was lowered to 75 IU daily and daily injections of 200 IU of hCG and a GnRH antagonist were administered until final maturation; group B, recombinant hFSH and a GnRH antagonist; group C, recombinant hFSH and a GnRH agonist.

MAIN OUTCOME MEASURE(S)

Primary outcome was the number of mature oocytes. Secondary outcomes included average initial and total recombinant hFSH dosage, serum E2 level on day of ovulation, number of oocytes retrieved, fertilization, number of top-quality embryos, endometrial thickness, implantation rate, pregnancy rate (PR), and incidence of ovarian hyperstimulation syndrome (OHSS).

RESULT(S)

The numbers of oocytes retrieved, mature oocytes, fertilization, top-quality embryos, and embryos transferred were comparable in all groups. Implantation rate, PR, and incidence of OHSS were also comparable. The total dose of recombinant hFSH was significantly lower in group A (1,674.7 +/- 59.4 IU, vs. 2,197.9 +/- 77.8 IU in group B and 2,156.7 +/- 80.9 IU in group C).

CONCLUSION(S)

This new OS protocol permits follicles and oocytes to fully develop, helps generate top-quality embryos, avoids premature ovulation, establishes clinical pregnancies, reduces administration of recombinant hFSH, minimizes costs, and does not increase the chances of OHSS.

Clinical outcome following stimulation with highly purified hMG or recombinant FSH in patients undergoing IVF: a randomized assessor-blind controlled trial

BACKGROUND

LH activity may influence treatment response and outcome in IVF cycles.

METHODS

A randomized, assessor-blind, multinational trial compared ongoing pregnancy rates (primary end-point) in 731 women undergoing IVF after stimulation with highly purified menotrophin (HP-hMG) (n = 363) or recombinant FSH (rFSH) (n = 368) following a long GnRH agonist protocol. Patients received identical pre- and post-randomization interventions. One or two embryos were transferred on day 3.

RESULTS

More oocytes were retrieved (P < 0.001) after rFSH treatment (11.8) compared with HP-hMG treatment (10.0), but a higher proportion developed into top-quality embryos (P = 0.044) with HP-hMG (11.3%) than with rFSH (9.0%). At the end of stimulation, lower estradiol (E(2)) (P = 0.031) and higher progesterone (P < 0.001) levels were found with rFSH, even after adjusting for follicular response. The distribution of hypo-, iso- and hyper-echogenic endometrium showed a significant (P = 0.023) shift towards the hyperechogenic pattern after rFSH treatment. The ongoing pregnancy rate per cycle was 27% with HP-hMG and 22% with rFSH [odds ratio (95% confidence interval): 1.25 (0.89-1.75)].

CONCLUSION

Superiority of HP-hMG over rFSH in ongoing pregnancy rate could not be concluded from this study, but non-inferiority was established. Pharmacodynamic differences in follicular development, oocyte/embryo quality, endocrine response and endometrial echogenicity exist between HP-hMG and rFSH preparations, which may be relevant for treatment outcome.

The significance of premature luteinization in an oocyte-donation programme

BACKGROUND

Several evidences indicate that premature luteinization (PL) may affect IVF outcome. The primary end-point of the present study was to verify the effect of PL on the pregnancy rate (PR) of our oocyte-donation programme.

METHODS

PL was defined as serum progesterone > or = 1.2 ng/ml on the day of HCG. We analysed retrospectively 240 oocyte-donation cycles in which 120 women donated twice, with PL in the first donation cycle and no PL in the following one, acting as its own control. Recipients (n = 240) were divided in two groups according to the presence of PL (n = 120) or not (n = 120). Both groups were compared regarding donor cycle parameters and recipient cycle outcome.

RESULTS

There was no difference in PR between the groups (55.7 versus 54.4%, respectively). The number of total oocytes (18.2 +/- 0.6 versus 20.8 +/- 0.6; P = 0.003) and the number of mature oocytes retrieved (16.9 +/- 0.6 versus 19.4 +/- 0.6; P = 0.005) were different among donors with progesterone < 1.2 ng/ml and PL, respectively. There were no differences between the oocyte recipients in fertilization, cleavage, embryo division on day 3, blastocyst development or fragmentation rates. The number of embryos transferred, number of embryos cryopreserved, and implantation and miscarriage rates were similar between the groups.

CONCLUSION

PL does not appear to have a negative impact on ongoing PR in our oocyte-donation programme.

Recombinant LH in ovarian stimulation

The advent of recombinant gonadotrophins brought significant changes in fertility therapy. Treatment options with recombinant gonadotrophins add more to knowledge on folliculogenesis and ovarian steroidogenesis. Over a decade, recombinant LH (rLH) has been used for clinical trials, and the amount of peripheral LH that is necessary for optimal follicular growth, oocyte maturation, subsequent embryo development and assisted reproduction outcome during ovulation induction can now be better evaluated. This review evaluates the effect of rLH supplementation on ovarian stimulation and assisted reproduction outcome. The studies conducted with rLH supplementation in ovarian stimulation in different groups of patients and in cases of controlled ovarian stimulation are clearly discussed in this review.

Novel concepts of human chorionic gonadotropin: reproductive system interactions and potential in the management of infertility

OBJECTIVE

To extensively review the scientific literature on the potential sites of hCG action and the role of this hormone on reproductive processes not necessarily related to the classic hCG functions of supporting early pregnancy.

DESIGN

Review of the international scientific literature and the authors' personal research experience in this area.

RESULT(S)

The LH/hCG receptor has an almost ubiquitous distribution in reproductive organs, thus suggesting that the actions of hCG might be more extensive than previously thought. Independently of FSH, low-dose hCG can support development and maturation of larger ovarian follicles that have acquired granulosa cells LH/hCG receptors, potentially providing effective and safer ovulation induction regimens. Human chorionic gonadotropin seems to be capable of improving uterine receptivity by enhancing endometrial quality and stromal fibroblast function. Furthermore, through its actions on insulin-like growth factor binding protein-1 and vascular endothelial growth factor, hCG might stimulate endometrial angiogenesis and growth and extend the implantation window, thus making pregnancy more likely.

CONCLUSION(S)

Mounting evidence indicates that hCG could be mediating relevant actions enhancing fertility and the efficacy of therapeutic procedures used in the management of infertility. Greater understanding of the physiologic roles that hCG plays in human reproduction might suggest novel clinical applications for this traditional hormone of pregnancy.

Impact of medically assisted fertility on preterm birth

Preterm birth is a frequent problem in women who undergo treatment for infertility. Many factors appear to contribute to the occurrence of this complication. Infertile women seem to have a predisposition to giving birth preterm and to having low birthweight babies. These complications also occur in women with a history of infertility who achieve pregnancy without treatment and who have singleton pregnancies. Assisted reproduction patients treated with in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) have a disproportionately high occurrence of preterm births even with singleton pregnancies. Spontaneous preterm labour may be related to underlying medical conditions of the female partner, as its occurrence is not increased in subjects treated with ICSI (i.e. when the infertility problem is associated with male reproductive dysfunction in normal female partners). Multiple pregnancy is the factor most likely to be related to preterm birth in infertile women. The administration of drugs to induce ovulation either alone or combined with intrauterine insemination causes a significant increase in multiple pregnancies. The occurrence of higher order multiple pregnancy is also increased. Multiple pregnancy in women undergoing IVF or ICSI is related to the number of embryos transferred at the end of treatment. The transfer of more than two embryos in women under 35 is not associated with an increased chance of conception, while the occurrence of multiple pregnancy is significantly increased. Women over 40 may benefit from the transfer of more than two embryos, with fewer risks of multiple pregnancy. Single embryo transfer is increasingly considered a workable clinical option, particularly in young women. Hopefully, a more cautious approach to infertility management will reduce the occurrence of multiple pregnancy, spontaneous preterm labour and the high number of low birthweight infants born after treating these women.

Treatment of female infertility with recombinant human luteinising hormone: is there a benefit over other available drugs?

This manuscript reviews the role of recombinant human luteinising hormone (rhLH) as a therapeutic drug in ovarian stimulation for assisted reproductive technology (ART) and ovulation induction. For this purpose, the role of LH during the follicular phase and during the ovulatory surge, along with the role of human chorionic gonadotropin (hCG) as a surrogate LH, is reviewed and compared to the results available with the new rhLH formulation. The use of rhLH was found to be safe and highly effective given during the follicular phase and to mimic an endogenous LH surge. The availability of both LH and follicle stimulating hormone (FSH) as separate recombinant preparations enables physicians to adjust the doses of each gonadotropin to the individual patient according to the 'therapeutic window' concept for each drug to maximise the success of ovarian stimulation.

Exogenous luteinizing hormone in controlled ovarian hyperstimulation for assisted reproduction techniques

OBJECTIVE

To investigate the role of exogenous LH in controlled ovarian hyperstimulation for assisted reproductive technologies.

DESIGN

Prospective randomized study.

SETTING

SISMER fertility unit.

PATIENT(S)

Women showing a hyporesponsiveness to FSH under GnRH agonist down-regulation were randomized into three groups: group A (n = 54) received an increased dosage of FSH; group B (n = 54) was administered recombinant LH in addition to the increased dose of FSH; group C (n = 22) was given additional FSH and LH using hMG as a combined drug. Fifty-four age-matched women with no need to increase the FSH dose were included as a control group (D).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Implantation and live birth rate per started cycles.

RESULT(S)

In group B, the pregnancy and implantation rates were statistically higher when compared with groups A and C and did not differ from the control group for normal response. The live birth rate was similar in groups B and D but was half as high in groups A and C.

CONCLUSION(S)

Hyporesponsiveness to FSH could be related to iatrogenic LH deficiency that, in turn, could affect oocyte competence. Addition of a small amount of recombinant LH is able to rescue oocyte competence to produce viable embryos.

The role of luteinizing hormone activity in controlled ovarian stimulation

The role of LH in the natural menstrual cycle is undisputed. The active participation of LH in both steroidogenesis and ovulation is well established, but its potential effect on oocyte maturation in the issue of assisted reproduction protocols remains a topic of debate. Although several studies have added to our understanding of the specific actions of androgens in human follicular development, some discrepancies persist regarding their role in oocyte atresia. Clinical situations, where LH is either decreased or absent (e.g. in women with hypogonadotrophic hypogonadism or LH-receptor gene mutations), provide important data supporting the necessity for a minimal amount of LH to evoke ovulation. Recent use of GnRH antagonists, which results in profound suppression of LH concentration, in combination with the pharmacological production of recombinant gonadotrophins, has attracted the attention of investigators. Identification of sub-fertilized women, in whom LH administration could be beneficial and should be indicated, is arousing ever more interest. Based on the available data in the literature, the aims of this review are to assess the role of both endogenous and exogenous LH activity in stimulated cycles, and to evaluate the effects of recombinant human LH supplementation on the ovarian hormonal milieu and on the main outcomes of controlled stimulated cycles.

Evaluation of mixed protocols with bravelle® (human-derived FSH) and repronex® (hMG) to assess clinical efficacy (EMBRACE) in women undergoing in vitro fertilization

OBJECTIVE

To compare the efficacy and safety of three different ratios of human-derived follicle-stimulating hormone/human menopausal gonadotropin (human-derived FSH:hMG, Bravelle and Repronex) mixed together in the same syringe and administered subcutaneously once daily, to in vitro fertilization (IVF) patients <34 years or 34 to 40 years of age.

DESIGN

Two randomized, prospective, age stratified, IVF studies.

SETTING

Twenty-one academic and private clinics with experience in IVF/embryo transfer (ET).

PATIENT(S)

Infertile premenopausal women undergoing IVF-ET.

INTERVENTION(S)

Pituitary suppression with leuprolide acetate, randomization to one of three treatment groups, followed by gonadotropin stimulation (GS) for up to 15 days. The human-derived FSH:hMG ratios were the following: Group 1, a 1:1 ratio throughout; Group 2, a 3:0 ratio that was changed to 1:1 after GS day 5; Group 3, a 2:1 ratio that was increased to 3:1, 4:1, or 5:1 after GS day 5, as needed.

MAIN OUTCOME MEASURE(S)

Mean number of oocytes retrieved; peak estradiol levels; dose and duration of stimulation; implantation rates; adverse events; injection site pain; and pregnancy and live birth rates.

RESULT(S)

Overall, women <34 years had higher E(2) levels, more oocytes retrieved, and improved implantation and live birth rates compared with women 34 to 40 years old. Nonetheless, each ratio of human-derived FSH:hMG produced comparable implantation rates, and continuing pregnancy and take-home baby rates.

CONCLUSION(S)

All three ratios of human-derived FSH:hMG in both age groups produced comparable pregnancy and live birth rates with similar safety results.

Premature luteinization during gonadotropin-releasing hormone antagonist cycles and its relationship with in vitro fertilization outcome

OBJECTIVE

To determine the prevalence and the effect of premature luteinization in GnRH antagonist IVF-ET cycles.

DESIGN

Prospective observational study.

SETTING

In vitro fertilization-embryo transfer (IVF-ET) program at the Instituto Valenciano de Infertilidad.

PATIENT(S)

Eighty-one infertile patients undergoing controlled ovarian hyperstimulation with gonadotropins and GnRH antagonist for IVF-ET.

INTERVENTION(S)

Gonadotropin-releasing hormone (GnRH) antagonist was administered from stimulation day 6. Serum P, E(2), and LH were determined on the day of hCG administration.

MAIN OUTCOME MEASURE(S)

Cycles were grouped according to serum P level on the day of hCG administration (<1.2 ng/mL or > or =1.2 ng/mL). Clinical pregnancy and implantation rates were determined.

RESULT(S)

The incidence of premature luteinization was 38.3%. Total recombinant FSH dose and stimulation days differed significantly between the groups. Pregnancy rate (25.8% vs. 54.0%) and implantation rate (13.8% vs. 32.0%) were significantly lower in the premature luteinization group.

CONCLUSION(S)

Premature luteinization during GnRH antagonist IVF-ET cycles is a frequent event that is associated with lower pregnancy and implantation rates. Progesterone elevations are not related to serum LH levels and may reflect the mature granulosa cell response to high FSH exposure.

Current concepts and novel applications of LH activity in ovarian stimulation

Luteinizing hormone (LH) is a crucial physiological regulator of the human menstrual cycle. LH activity is also contained in many medications used to treat anovulation and to stimulate multiple folliculogenesis for assisted reproduction techniques. However, LH activity had previously been regarded as just a contaminant of follicle-stimulating hormone (FSH)-containing products and deemed potentially detrimental for reproductive function. Novel experimental and clinical evidence now suggests that the administration of pharmacological amounts of LH activity, instead of being harmful, is therapeutically advantageous, particularly in the support and modulation of ovarian folliculogenesis. The aim of this article is to provide an overview of the effects of LH activity administration in ovarian stimulation and to outline novel unconventional gonadotropin regimens that might improve the efficacy, safety and convenience of ovulation induction.

Comparison of controlled ovarian stimulation with human menopausal gonadotropin or recombinant follicle-stimulating hormone

OBJECTIVE

To carefully examine the features of controlled ovarian stimulation performed with recombinant FSH-alpha or hMG.

DESIGN

Controlled, prospective, randomized comparison of fixed gonadotropin regimens.

SETTING

Academic research institution.

PATIENT(S)

Fifty infertile patients who were candidates for IUI.

INTERVENTION(S)

Patients were randomized to receive a fixed regimen of recombinant FSH-alpha (150 IU/day, 25 patients) or hMG (150 IU/day, 25 patients), after GnRH-agonist suppression (long regimen).

MAIN OUTCOME MEASURES

Daily measurements of serum LH, immunoreactive FSH, hCG, E(2), P, and T. Transvaginal pelvic ultrasound every 2 days. Pregnancy and abortion rates. Cost of medications. Two recombinant FSH-alpha-treated patients did not respond. Despite matched daily FSH dose, duration of treatment (hMG 10.8 +/- 0.4 vs. recombinant FSH-alpha 12.4 +/- 0.5 days), gonadotropin dose (21.7 +/- 0.8 vs. 25.3 +/- 1.3 ampoules), gonadotropin cost (288 +/- 10 vs. 1,299 +/- 66 /cycle), serum P levels, and small preovulatory follicle number were significantly lower, and LH, hCG, immunoreactive FSH levels, and larger follicles on day 8 were significantly higher in hMG-treated patients. The pregnancy, abortion, and twin pregnancy rates did not differ.

CONCLUSION

The hMG administration was associated with: [1]. increased serum LH activity and immunoreactive FSH levels during treatment; [2]. reduced signs of premature luteinization; [3]. differential modulation of folliculogenesis; [4]. lower treatment duration, gonadotropin dose, and cost; and [5]. clinical outcome comparable to recombinant FSH-alpha.

Does the Addition of Luteinizing Hormone in Ovarian Stimulation Protocols Improve the Outcome?

Ovarian stimulation is an integral part of assisted reproductive technologies (ART). Under physiologic conditions, both follicle-stimulating hormone (FSH) and luteinizing hormone (LH) activity is necessary to guarantee follicle growth and maturation. This can be shown in patients with hypogonadotrophic hypogonadism, who have no endogenous FSH or LH activity. The use of FSH alone in these patients does not result in sufficient follicle growth and oocyte quality. Approximately 75IU of LH activity per day is necessary to guarantee optimal success. The use of gonadotropin-releasing hormone (GnRH) agonists in normogonadotrophic patients may result in suppression of LH levels below a certain threshold, resulting in suboptimal outcomes. The question under discussion in this article is the threshold level of LH below which exogenous LH activity should be added to provide optimal ovarian response. Different studies indicate that the endogenous LH level should be 0.5-1.5IU in long-term protocol situations. Patients treated in ultra-long GnRH agonist protocols, as well as older patients, patients with a low response to gonadotropin treatment, and patients treated with a GnRH antagonist protocol may benefit from exogenous LH activity. There are three ways of adding LH activity in ovarian stimulation cycles. Nowadays, lutropin alfa (recombinant LH) may be the optimal choice since it has no chorionic gonadotropin activity and allows individual dosage titration. Every menotropin preparation currently on the market contains some chorionic gonadotropin activity. However, more data are necessary before evidence-based recommendations regarding LH supplementation in ovarian stimulation protocols can be given.