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Only Gonadotropin Vs. Letrozole Combined Gonadotropin Stimulation in IUI Cycles

Comparison of Two Ovarian Stimulation Strategies in Intrauterine Insemination Cycles of Couples With Unexplained Infertility; Only Gonadotropin Vs. Letrozole Combined Gonadotropin Stimulation. A Randomized Controlled Trial.

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06413771
Enrollment
131
Registered
2024-05-14
Start date
2023-01-01
Completion date
2024-02-01
Last updated
2024-05-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Infertility Unexplained

Keywords

unexplained infertility, letrozole, gonadotropin, intrauterine insemination

Brief summary

The present randomized controlled study aims to investigate the effectiveness of a combined regimen of letrozole and gonadotropin with dose adjustments based on body mass index (BMI) compared to a conventional only gonadotropin regimen in intrauterine insemination (IUI) cycles for couples experiencing unexplained infertility. The study was conducted at a tertiary university hospital's Assisted Reproductive Technologies (ART) center from January 2023 to January 2024. Couples with unexplained infertility were enrolled based on comprehensive assessments, and randomization was performed based on national ID (odd or even). The Conventional Only Gonadotropin (COG) group received recombinant FSH based on body mass index (BMI), while the Combined Letrozole-Gonadotropin (CLG) group received letrozole followed by gonadotropin with dose adjustments based on BMI. Ovulation induction and IUI were performed according to standard protocols. Clinical outcomes, gonadotropin consumption, and pregnancy rates were compared between groups. Among 317 IUI cycles, 131 couples with unexplained infertility were randomized (CLG: 61, COG: 70). Demographic parameters were similar between groups. The CLG group had lower daily gonadotropin doses (67 ± 18 IU/D vs. 76 ± 11 IU/d, p=0.01) and total gonadotropin consumption (750 IU vs. 825 IU, p=0.01) with comparable ovulation and clinical pregnancy rates. The COG group exhibited higher multiple pregnancy rates, although not statistically significant (CLG vs. COG; 1/61 vs. 3/70, p=0.4). The study suggests that the combined letrozole and gonadotropin regimen with BMI-based dose adjustments in IUI cycles for unexplained infertility is associated with reduced gonadotropin consumption and potentially lower multiple pregnancy rates.

Interventions

DRUGLetrozole 2.5mg

Letrozole pretreatment during ovarian stimulation with gonadotropins, in intrauterine insemination cycles.

Ovarian stimulation with gonadotropins, in intrauterine insemination cycles.

Sponsors

Uludag University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Investigator)

Masking description

Patients were divided into two study arms based on the initial digits of their national IDs by ART nurses. Importantly, the IVF clinicians remained blinded to the patients' grouping throughout the study.

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 35 Years
Healthy volunteers
No

Inclusion criteria

* Couples with unexplained infertility * Aged between 18-35

Exclusion criteria

* Male factor infertility * Diminished ovarian reserve * Patient refusion to participate

Design outcomes

Primary

MeasureTime frameDescription
Clinical Pregnancy Rate6 weeksPresence of gestational sac by transvaginal ultrasound

Secondary

MeasureTime frameDescription
Multiple Pregnancy Rate6 weeksPresence of multipl gestational sacs by transvaginal ultrasound

Countries

Turkey (Türkiye)

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026