Letrozole and gonadotropins versus luteal estradiol and gonadotropin-releasing hormone antagonist protocol in women with a prior low response to ovarian stimulation

Live birth associated with peak serum estradiol levels in letrozole intrauterine insemination cycles

OBJECTIVE

To identify whether the serum estradiol (E2) level on the day of human chorionic gonadotropin (hCG) trigger or luteinizing hormone (LH) surge (hCG-LH) was associated with the live birth rate (LBR) during ovulation induction (OI) or controlled ovarian hyperstimulation with letrozole followed by intrauterine insemination (IUI).

DESIGN

Retrospective cohort study.

SETTING

Large, multicenter private practice.

PATIENT(S)

A total of 2,368 OI-IUI cycles in patients treated with letrozole followed by IUI were evaluated from January 1, 2014, to July 31, 2019.

INTERVENTION(S)

Ovulation induction with letrozole, followed by autologous IUI.

MAIN OUTCOME MEASURE(S)

The primary outcome measure was the LBR as a function of the serum E2 level at the time of hCG administration or LH surge, adjusting for age, body mass index, the largest follicle diameter, and the number of follicles ≥14 mm in diameter. The clinical pregnancy rate as a function of the E2 level, pregnancy rate as a function of the lead follicle diameter, and pregnancy loss rates were the secondary outcome variables.

RESULT(S)

A total of 2,368 cycles met the inclusion criteria. Outcomes were evaluated at the 25th (E2 level, 110 pg/mL), 50th (157 pg/mL), 75th (225 pg/mL), and 90th (319 pg/mL) percentiles. The LBRs ranged from 9.4% to 11.1% in the lower E2 cohorts and from 12.5% to 13.5% in the higher E2 cohorts. The LBR was significantly greater in the cohort of women with higher E2 levels in all percentile comparisons except for the 90th percentile. The mean periovulatory follicle diameter of ≥20 or <20 mm was not independently associated with the LBR or clinical pregnancy rate, despite a significantly higher mean E2 level in the larger follicle group.

CONCLUSION(S)

In letrozole OI cycles followed by IUI, lower LBRs and clinical pregnancy rates were found in women with lower E2 levels than in those with higher E2 levels at the 25th, 50th, and 75th percentile E2 level quartiles. Where possible, delaying hCG trigger until the E2 level increases after aromatase inhibition and approaches the physiologic periovulatory level may improve the pregnancy rates with letrozole followed by IUI.

Comparison of the standard GnRH antagonist protocol and the luteal phase estradiol/GnRH antagonist priming protocol in poor ovarian responders

BACKGROUND/AIM

The aim of the study was to compare the luteal estradiol patch/GnRH antagonists priming protocol (LPP) with the standard GnRH antagonist protocol in poor ovarian responders (PORs) in terms of the outcomes of in vitro fertilization (IVF) treatment.

MATERIALS AND METHODS

IVF outcomes of 265 cycles in 265 patients (106 in the LPP group, 159 in the standard GnRH antagonist group) were evaluated retrospectively.

RESULTS

Mean length of stimulation (11.4 ± 2.7 vs. 10.0 ± 2.7 days; P < 0.05) and the total gonadotropin dose (3403 ± 1060 vs. 2984 ± 1112) used were significantly greater in the LPP group than in the standard GnRH antagonist protocol group. The mean number of oocytes retrieved (3.5 ± 2.6 vs. 3.7 ± 2.8), the number of mature oocytes (2.8 ± 2.2 vs. 2.6 ± 2.2), fertilization rates (65% vs. 62%), the number of embryos transferred (1.6 ± 0.6 vs. 1.7 ± 0.6), and implantation rates (16% vs. 13%) were similar. The cancellation rate did not significantly differ between the groups (9.4% vs. 13.2%). There were no significant differences in the clinical pregnancy (11.3% vs. 13.2%) or live birth rates per patient (3.8% vs. 9.4%) and clinical pregnancy (18.8% vs. 22.6%) or live birth rates per embryo transfer (6.3% vs. 12.9%) between the groups.

CONCLUSION

LPP does not improve IVF outcomes when compared with the standard GnRH antagonist protocol in PORs.

A randomized, single-blind, prospective trial comparing three different gonadotropin doses with or without addition of letrozole during ovulation stimulation in patients with poor ovarian response

OBJECTIVE

The aim of this randomized controlled trial (RCT) was to investigate whether IVF outcomes would differ between patients with POR who received three different gonadotropin doses with or without the addition of letrozole during ovulation stimulation.

STUDY DESIGN

Only those who fulfilled two of the three Bologna criteria were included to the study. 95 patients met the inclusion criteria and agreed to participate in the study. In the first group, 31 patients were treated with 450IU gonadotropins. In the second group, 31 patients were treated with 300IU gonadotropins. The third group comprised 33 patients and was treated with 150IU gonadotropins in combination with letrozole.

RESULTS

The results indicate that differences in doses of hMG and rFSH in patients with POR result in a similar number of retrieved MII and fertilized oocytes, similar fertilization rates, number of transferred embryos, implantation, cancelation, chemical, clinical, and ongoing pregnancy rates.

CONCLUSIONS

Increasing the dose of gonadotropins during ovulation stimulation is an intuitively appealing approach when the patient is a poor responder. However, increasing the dose does not necessarily improve the reproductive outcome. Using a mild stimulation with addition of letrozole was as effective as stimulation with higher doses of gonadotropins alone in this patient population.

The association of serum estradiol level with outcomes of clomiphene citrate/human menopausal gonadotropin ovarian stimulation for in vitro fertilization and embryo transfer

BACKGROUND

The purpose of this study was to test the hypothesis that estradiol (E2) level on day 3 may be associated with in vitro fertilization (IVF) outcomes.

METHODS

The records of patients who received clomiphene citrate 100 mg/day plus human menopausal gonadotropin 150 IU/day from day 3 and received frozen-thawed embryo transfers were reviewed. Patients were divided into three groups: group A (E2 ≤30 pg/ml), group B (30< E2 ≤50 pg/ml), and group C (E2 >50 pg/ml). A total of 1080 cycles from 941 patients were included.

RESULTS

The number of eggs and MII oocytes were less in group C than group A (both, P = 0.001). The embryo implantation (P = 0.006) and clinical pregnancy rates (P = 0.036) were lower in group C than group B, and the rates were similar between group A and B.

CONCLUSION

Maintaining the serum E2 level from 30 to 50 pg/ml may result in a higher clinical pregnancy rate in IVF cycles.

Estrogen or anti-estrogen for Bologna poor responders?

The current study aims to compare cycle outcomes of two ovarian stimulation protocols in poor responders according to the Bologna criteria; luteal estrogen priming (LE) or letrozole (LZ) co-treatment in antagonist protocol. Following retrospective chart review of a single center, 162 cycles were found eligible for the comparison of two ovarian stimulation protocols. After interpreting data, significantly higher serum estradiol levels, longer duration of cycle, higher number of fertilized oocytes and good quality embryos were detected in patients who received LE. Despite any statistical significance, higher clinical pregnancy rate (CPR) and ongoing pregnancy rate (OPR) per embryo transfer (ET) were detected with LE protocol compared with LZ (12.3% versus 18.2% and 9.6% versus 12.7%, respectively). Younger patients (<40 years) revealed higher CPR and OPR per started cycle compared with older patients (≥40 years) where only OPR was statistically significant. Multivariable analysis demonstrated that basal antral follicle count, peak serum estradiol levels and number of fertilized oocytes were independent variables significantly associated with clinical pregnancies (p < 0.05). In the current analysis, LE or LZ protocols revealed comparable but quite low pregnancy rates in poor responders according to the Bologna criteria. Younger patients were more likely to achieve pregnancy compared to older patients with both protocols.

Cycle cancellation and pregnancy after luteal estradiol priming in women defined as poor responders: a systematic review and meta-analysis

STUDY QUESTION

Does a luteal estradiol (LE) stimulation protocol improve outcomes in poor responders to IVF?

SUMMARY ANSWER

LE priming is associated with decreased cycle cancellation and increased chance of clinical pregnancy in poor responders

WHAT IS KNOWN ALREADY

Poor responders to IVF are one of the most challenging patient populations to treat. Many standard protocols currently exist for stimulating these patients but all have failed to improve outcomes.

STUDY DESIGN, SIZE, DURATION

Systematic review and meta-analysis including eight published studies comparing assisted reproduction technology (ART) outcomes in poor responders exposed to controlled ovarian hyperstimulation with and without LE priming. A search of the databases MEDLINE, EMBASE and PUBMED was carried out for studies in the English language published up to January 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Studies evaluating women defined as poor responders to ART were evaluated. These studies were identified following a systematic review of the literature and data were analyzed using the DerSimonian-Laird random effects model. The main outcomes of interest were cycle cancellation rate and clinical pregnancy. Although the definition of clinical pregnancy varied between studies, the principal definition included fetal cardiac activity as assessed by transvaginal ultrasonography after 5 weeks of gestation.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 2249 publications were identified from the initial search, and the bibliographies, abstracts and other sources yielded 11 more. After excluding duplications, 1227 studies remained and 8 ultimately met the inclusion criteria. Compared with women undergoing non-LE primed protocols (n = 621), women exposed to LE priming (n = 468) had a lower risk of cycle cancellation [relative risk (RR): 0.60, 95% confidence interval (CI): 0.45-0.78] and an improved chance of clinical pregnancy (RR: 1.33, 95% CI: 1.02-1.72). There was no significant improvement in the number of mature oocytes obtained or number of zygotes obtained per cycle.

LIMITATIONS, REASONS FOR CAUTION

These findings are limited by the body of literature currently available. As the poor responder lacks a concrete definition, there is some heterogeneity to these results, which merits caution when applying our findings to individual patients. Furthermore, the increased clinical pregnancy rate demonstrated when using the LE protocol may be principally related to the decreased cycle cancellation rate.

WIDER IMPLICATIONS OF THE FINDINGS

The LE protocol may be of some utility in the poor responder to IVF and may increase clinical pregnancy rates in this population by improving stimulation and thereby decreasing cycle cancellation.

STUDY FUNDING/COMPETING INTERESTS

NIH K12 HD063086 (ESJ, MGT), NIH T32 HD0040135-11 (KAR), F32 HD040135-10 NIH (KRO), 5K12HD000849-25 (PTJ). No competing interests.