Ovulation rates in a stair-step protocol with Letrozole vs clomiphene citrate in patients with polycystic ovarian syndrome

A comparison of letrozole regimens for ovulation induction in women with polycystic ovary syndrome

Objective

To determine the optimal letrozole regimen for ovulation induction (OI) in women with polycystic ovary syndrome (PCOS).

Design

Retrospective cohort study.

Setting

Single academic fertility clinic from 2015-2022.

Patients

A total of 189 OI cycles in 52 patients with PCOS.

Interventions

Patients were prescribed 1 of 4 letrozole regimens (group 1: 2.5 mg for 5 days, group 2: 2.5 mg for 10 days, group 3: 5 mg for 5 days, and group 4: 5 mg for 10 days).

Main outcome measures

The primary outcome was ovulation, and secondary outcomes included multifollicular development, and clinical pregnancy rate, which were analyzed with binary logistic regression. Kaplan-Meier cumulative response curves and a Cox proportional hazard regression model were used for time-dependent analyses.

Results

Mean age was 30.9 years (standard deviation [SD], 3.6) and body mass index was 32.1 kg/m2 (SD, 4.0). Group 2 (odds ratio [OR], 9.12; 95% confidence interval [CI], 1.92-43.25), group 3 (OR, 3.40; 95% CI, 1.57-7.37), and group 4 (OR, 5.94; 95% CI, 2.48-14.23) had improved ovulation rates after the starting regimen as compared with group 1. Cumulative ovulation rates exceeded 84% in all groups, yet those who received 5 mg and/or 10 days achieved ovulation significantly sooner. Multifollicular development was not increased in groups 2-4 as compared with group 1. Groups 2-4 also demonstrated improved time to pregnancy.

Conclusions

Ovulation rates are improved when starting with letrozole at 5 mg and/or a 10-day extended course as compared with the frequently-used 2.5 mg for 5 days. This may shorten time to ovulation and pregnancy.

Finding of the optimal preparation and timing of endometrium in frozen-thawed embryo transfer: a literature review of clinical evidence

Frozen-thawed embryo transfer (FET) has been a viable alternative to fresh embryo transfer in recent years because of the improvement in vitrification methods. Laboratory-based studies indicate that complex molecular and morphological changes in endometrium during the window of implantation after exogenous hormones with controlled ovarian stimulation may alter the interaction between the embryo and endometrium, leading to a decreased implantation potential. Based on the results obtained from randomized controlled studies, increased pregnancy rates and better perinatal outcomes have been reported following FET. Compared to fresh embryo transfer, fewer preterm deliveries, and reduced incidence of ovarian hyperstimulation syndrome were found after FETs, yet there is a trend of increased pregnancy-related hypertensive diseases in women receiving FET. Despite the increased application of FET, the search for the most optimal priming protocol for the endometrium is still undergoing. Three available FET protocols have been proposed to prepare the endometrium: i) natural cycle (true natural cycle and modified natural cycle) ii) artificial cycle (AC) or hormone replacement treatment cycle iii) mild ovarian stimulation (mild-OS) cycle. Emerging evidence suggests that the optimal timing for FET using warmed blastocyst transfer is the LH surge+6 day, hCG administration+7 day, and the progesterone administration+6 day in the true natural cycle, modified natural cycle, and AC protocol, respectively. Although still controversial, better clinical pregnancy rates and live birth rates have been reported using the natural cycle (true natural cycle/modified natural cycle) compared with the AC protocol. Additionally, a higher early pregnancy loss rate and an increased incidence of gestational hypertension have been found in FETs using the AC protocol because of the lack of a corpus luteum. Although the common clinical practice is to employ luteal phase support (LPS) in natural cycles and mild-OS cycles for FET, the requirement for LPS in these protocols remains equivocal. Recent findings obtained from RCTs do not support the routine application of endometrial receptivity testing to optimize the timing of FET. More RCTs with rigorous methodology are needed to compare different protocols to prime the endometrium for FET, focusing not only on live birth rate, but also on maternal, obstetrical, and neonatal outcomes.

Ovulation induction with letrozole and dexamethasone in infertile patients with letrozole-resistant polycystic ovary syndrome

PURPOSE

To assess efficacy of adjuvant dexamethasone during letrozole cycles for ovulation induction (OI) in women with letrozole-resistant polycystic ovary syndrome (PCOS).

METHODS

We retrospectively evaluated 42 cycles of OI from 28 infertile women with letrozole-resistant PCOS between September 2019 and November 2022. Letrozole was initiated on cycle day 3 for 5 days and increased via a stair-step approach to 7.5 mg as indicated. Patients were deemed letrozole-resistant if no dominant follicle was identified on transvaginal ultrasound following this dose. Resistant patients then received 5 additional days of letrozole 7.5 mg with low-dose dexamethasone 0.5 mg for 7 days and had a repeat ultrasound. The primary outcome was ovulation rate determined by the presence of a dominant follicle on ultrasound. Secondary outcomes included endometrial thickness, number of measurable follicles, and pregnancy outcomes among responders.

RESULTS

Twenty-two of 28 (79%) letrozole-resistant PCOS patients had evidence of ovulation after the addition of dexamethasone in 35 out of 42 (83%) cycles. Clinical pregnancy occurred in 20% of ovulatory cycles with a cumulative rate of 32%. All clinical pregnancies resulted in a live birth. Patients who responded to adjuvant dexamethasone were more likely to have a shorter duration of infertility; however, there were no differences in other demographics, serum androgens including DHEA-S, or pretreatment glycemic status.

CONCLUSION

Adding dexamethasone to letrozole increased ovulation rates in letrozole-resistant PCOS patients undergoing OI with similar pregnancy outcomes to prior studies. The addition of dexamethasone is an effective, inexpensive, and safe option for PCOS patients otherwise at risk for cycle cancelation.

Comparing efficacy and safety of stair step protocols for clomiphene citrate and letrozole in ovulation induction for women with polycystic ovary syndrome (PCOS): a randomized controlled clinical trial

Polycystic ovary syndrome (PCOS) is characterized by menstrual irregularities, high androgen levels, and ovarian cysts. Clomiphene citrate (Clomid) and letrozole have both been investigated as ovulation induction therapies for PCOS. This interventional study aimed to compare the efficacy and safety of a stairstep practice of letrozole versus clomiphene citrate in women with PCOS. A total of 100 women diagnosed with PCOS and infertility participated in the study, which took place from March 2021 to July 2022 at the Maternity and Children Teaching Hospital in Adiwaniyah Province, Iraq. Participants were randomly assigned to one of two groups (each with 50 women): the first group received clomiphene citrate in a stair step pattern (single dose of 50 mg, 100 mg, and 150 mg) for five days, for a maximum of three cycles; the second group received letrozole in a stair step pattern (single dose of 2.5, 5, and 7.5 mg) for five days, for a maximum of three cycles. Follicle size was monitored using ultrasound to achieve a follicle size >18 mm. The ovulation rate was higher in the letrozole group (86.0%) compared to the clomiphene citrate group (72.0%), although the difference was not statistically significant (p=0.086). The pregnancy rate was slightly higher in the letrozole group (22.0% vs 18.0%), but also not statistically significant (p=0.617). However, the mean time from menstruation to ovulation was significantly shorter in the letrozole group (17.20±1.32 days) compared to the clomiphene citrate group (24.08 ± 1.56 days, p<0.001). There were no significant differences in common side effects between the two groups. Overall, letrozole was found to be as safe as clomiphene citrate but demonstrated a shorter time to ovulation. Further studies with larger sample sizes are necessary to validate these findings and determine their clinical implications.

Extending letrozole treatment duration is effective in inducing ovulation in women with polycystic ovary syndrome and letrozole resistance

OBJECTIVE

To evaluate whether extending letrozole (LE) treatment duration could induce ovulation in women with polycystic ovary syndrome (PCOS) who previously failed to ovulate after a 5-day regimen of 5 mg LE daily for at least 1 ovulation induction cycle, defined as "LE resistance".

DESIGN

Retrospective cohort study.

SETTING

Tertiary care academic medical center.

PATIENT(S)

A total of 69 women with PCOS and LE resistance were included.

INTERVENTION(S)

The duration of LE treatment was increased in a stepwise manner (named as "2-step extended LE regimen"): a 7-day regimen of 5 mg LE daily was prescribed in the first ovulation induction cycle, and if ovulation did not occur, a 10-day regimen was prescribed in the subsequent cycle.

MAIN OUTCOME MEASURE(S)

Ovulation rate was the primary outcome. Clinical pregnancy rate, live birth rate, spontaneous ovulation rate, and ovarian hyperstimulation syndrome rate were the secondary outcomes.

RESULT(S)

Of the 69 patients, 48 ovulated after the 7-day and 16 after the 10-day regimen. Overall, the cumulative ovulation rate reached 92.75% (64/69) after the 2-step extended LE regimen, with a cumulative clinical pregnancy rate of 31.88% (22/69) and a cumulative live birth rate of 24.63% (17/69). All patients ovulated spontaneously without exogenous trigger agents and none experienced ovarian hyperstimulation syndrome.

CONCLUSION(S)

Extending LE treatment duration is a feasible method for inducing ovulation in women with PCOS and LE resistance.

D-chiro-inositol Induces Ovulation in Non-Polycystic Ovary Syndrome (PCOS), Non-Insulin-Resistant Young Women, Likely by Modulating Aromatase Expression: A Report of 2 Cases

Case series

Patients: Female, 19-year-old • Female, 23-year-old

Final Diagnosis: Anovulation

Symptoms: Oligomenorrhea

Medication: —

Clinical Procedure: —

Specialty: Obstetrics and Gynecology

Comparison of the efficacy of letrozole stair-step protocol with clomiphene citrate stair-step protocol in the management of clomiphene citrate-resistant polycystic ovary syndrome patients

PURPOSE

We sought to compare the efficacy of the letrozole (LTZ) stair-step protocol with clomiphene citrate (CC) stair-step protocol in the management of 150 mg dose of CC-resistant polycystic ovary syndrome (PCOS) patients.

METHODS

We retrospectively compared a total of 61 patients diagnosed as being resistant to the traditional CC protocol who were subsequently managed using the LTZ stair-step protocol with CC-resistant 56 patients who were treated with CC stair-step protocol. The number of follicles ≥18 mm, endometrial thickness, time to ovulation, clinical pregnancy rates, multiple pregnancy rates, spontaneous abortion rates, live birth rates, and systemic side effects in patients were evaluated.

RESULTS

The mean time to ovulation was significantly shorter in the LTZ stair-step group than the CC stair-step group (17.3 ± 7.7 and 22.4 ± 8.1 days, respectively, p < 0.001). The ovulation rate was significantly higher in patients treated with LTZ stair-step protocol than those treated with the CC stair-step protocol (83.6% and 64.2%, respectively, p = 0.007). The clinical pregnancy rate was higher in the LTZ stair-step than the CC stair-step group (32.7% and 17.8%, respectively, p = 0.015). LTZ stair-step group had a significantly higher live birth rate than that of the CC stair-step group (27.8% and 14.2%, respectively, p = 0.012).

CONCLUSION

The LTZ stair-step protocol revealed higher ovulation, clinical pregnancy, and live birth rates with a shorter time to achieve ovulation than the CC stair-step protocol. Increment of the dose in the same cycle in both protocols did not cause any additional severe side effects.