An observational study in Female Subjects Undergoing Controlled Ovarian Hyperstimulation, sponsored by McGill University Health Centre/Research Institute of the McGill University Health Centre. Not yet recruiting at 1 site in Canada. Open to female participants aged 18 Years to 44 Years. Per ClinicalTrials.gov, last updated 2026-03-10.
Sponsored by McGill University Health Centre/Research Institute of the McGill University Health Centre · Observational
Follicle-stimulating hormone (FSH) plays a central role in controlled ovarian stimulation (COS) during in vitro fertilization (IVF) cycles. While baseline FSH is commonly used to assess ovarian reserve, the clinical significance of dynamic FSH changes during stimulation remains unclear. Limited evidence suggests that serum FSH levels during COS may reflect ovarian response and could be associated with follicular development and treatment outcomes, yet FSH is not routinely monitored throughout stimulation protocols.
This prospective single-center cohort study aims to evaluate the dynamics of serum FSH levels during COS and to examine their association with ovarian response and IVF outcomes. Serum FSH, luteinizing hormone (LH) and estradiol (E2) will be measured at predefined time points during stimulation. Associations between FSH levels and oocyte yield, embryo development, and pregnancy outcomes will be analyzed to better understand the clinical relevance of FSH monitoring during IVF treatment.
Background and Rationale
Follicle-stimulating hormone (FSH), secreted by the anterior pituitary gland in response to gonadotropin-releasing hormone (GnRH), plays a critical role in ovarian follicular development and estradiol production. In assisted reproductive technologies (ART), exogenous FSH is administered during controlled ovarian stimulation (COS) to promote multifollicular growth. Although baseline FSH is widely used as a marker of ovarian reserve and predictor of ovarian response, the clinical significance of dynamic FSH changes during stimulation remains insufficiently characterized.
Day 7 of stimulation represents a clinically important time point during which follicular growth and synchronization are assessed. Prior studies have suggested that serum FSH levels during COS may correlate with ovarian response and may reflect an individualized FSH threshold beyond which increasing exogenous dosing may not improve follicular recruitment. However, consensus is lacking regarding the clinical utility of serial FSH monitoring during stimulation, and it is not routinely incorporated into IVF protocols.
Understanding the relationship between FSH dynamics, follicular development, estradiol production, and treatment outcomes may support more individualized stimulation strategies and improve reproductive outcomes.
Study Design
This is a prospective observational cohort study conducted at a single academic fertility center at the McGill University Health Centre (MUHC) Reproductive Centre.
Study Population
Eligible participants include patients undergoing controlled ovarian stimulation for IVF or ICSI at the MUHC Reproductive Centre. All stimulation protocols (GnRH agonist and antagonist) and all gonadotropin formulations (including Gonal-F, Menopur, Rekovelle, and Puregon) are included.
Data Collection
Demographic and clinical data will include age, body mass index (BMI), obstetric history, indication for treatment, and stimulation protocol details.
Serum hormone levels of will be measured at three predefined time points:
Blood samples will be collected at time points that coincide with routine visits for women undergoing ovarian stimulation, during which blood tests are already performed as part of standard clinical care
The hormones measured include:
Serum Follicle-stimulating hormone (FSH) (mIU/mL) Luteinizing hormone (LH) (mIU/mL) Estradiol (E2) (pmol/L) Anti-Müllerian Hormone (AMH) (ng/mL)
McGill University Health Centre/Research Institute of the McGill University Health Centre is the lead sponsor of 414 studies on the registry; 106 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Study will include patients undergoing controlled ovarian stimulation at the MUHC Reproductive Center. Nursing and medical team will recruit patients on their initial visit when they get their treatment plan and prescription at the MUHC Reproductive Center.
Exclusion Criteria:
Patients undergoing controlled ovarian stimulation at the MUHC Reproductive Center.
-Trigger day FSH levels
Serum Follicle-stimulating hormone (FSH) (mIU/mL) measured at the day of the trigger shot
Time frame: 60 months
Trigger day E2 levels
Serum Estradiol (E2) (pg/mL) levels measured at trigger shot day
Time frame: 60 months
Number of patients reaching trigger
The number of patients that received the trigger shot and proceeding to oocyte retrieval / The number pf patients canceled during the ovarian stimulation
Time frame: 60 months
Number of oocytes retrieved
The number of oocytes collected in the oocyte retrieval procedure
Time frame: 60 months
Number of transferable embryos
Number of embryos were transferred in the fresh cycle plus the number of frozen embryos
Time frame: 60 months
Biochemical pregnancy rate
Positive pregnancy test (i.e positive serum HCG level \>20 U/L after 11 days of ET of D5 embryo and 13 after D3 embryo transfer) per transfer
Time frame: 60 months
Clinical pregnancy rate
Pregnancy diagnosed by ultrasound with at least one embryo and a discernable heartbeat per transfer
Time frame: 60 months
Miscarriage rate
Spontaneous loss of clinical pregnancy before 12 weeks per transfer
Time frame: 60 months
Plan to share: No
This study is not yet recruiting, as verified in Mar 2026. You cannot join it, but the record below documents what was studied.
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McGill University Health Centre/Research Institute of the McGill University Health Centre