Delaying the ovulation trigger in antagonist IVF cycles
Comparison of Regular Trigger Timing and 1～2 Days Delay of Trigger in Ovarian Stimulations by GnRH Antagonist Protocol in in Vitro Fertilization
This trial will test whether waiting 1–2 days before the ovulation trigger improves embryo quality for people having IVF with an antagonist protocol.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 834 (estimated) |
| Ages | 18 Years to 42 Years |
| Sex | Female |
| Sponsor | Peking University Third Hospital Academic / other |
| Locations | 1 site (Beijing, Beijing Municipality) |
| Trial ID | NCT04163133 on ClinicalTrials.gov |
What this trial studies
This single-center, open-label randomized controlled trial at Peking University Third Hospital will assign eligible patients 1:1 to standard trigger timing (when three follicles reach ≥17 mm) or to a trigger delayed by 1–2 days. Ovarian stimulation uses a fixed antagonist protocol with oocyte retrieval performed 36–38 hours after trigger, followed by IVF/ICSI, standard embryo culture, and planned day-3 single or double transfer. The primary outcome is the number of good-quality embryos, with secondary outcomes including cumulative live birth rate and routine IVF safety and efficiency measures. All participant data and outcomes will be recorded in case report forms and analyzed according to the prespecified protocol.
Who should consider this trial
Good fit: Ideal candidates are people aged 18–41 with AFC 5–19, AMH 1.1–2.5 ng/mL, BMI 18.5–29 kg/m2, regular menstrual cycles, two ovaries, and undergoing their first or second IVF/ICSI cycle using a fixed antagonist protocol.
Not a fit: Patients with poor ovarian reserve, significant medical contraindications to IVF, or who fall outside the specified AMH, AFC, BMI, or age ranges are unlikely to benefit from this approach.
Why it matters
Potential benefit: If successful, delaying the trigger by 1–2 days could increase the number of good-quality embryos and potentially improve cumulative live birth rates.
How similar studies have performed: Some observational work suggests antagonist timing can affect oocyte maturation and endometrial receptivity, but randomized evidence specifically testing a 1–2 day trigger delay is limited.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Age: ≥18 and \<42 years old * AFC: ≥5 and \<20 * AMH: ≥1.1 ng/mL and \<2.5 ng/mL * BMI: ≥18.5 Kg/m2 and \<29 Kg/m * First or second ART cycle * Regular menstrual cycles (between 22 and 35 days) * Two ovaries present * Planned for single or double day 3 transfer * Infertile couples scheduled for their first IVF/ICSI cycle with fixed antagonist protocol. * Informed consent obtained. Exclusion Criteria: * Women with contraindication for IVF or ICSI, such as poorly controlled type 1 or type 2 diabetes mellitus; undiagnosed liver disease or dysfunction (based on serum liver enzyme test results); renal disease or abnormal serum renal function; significant anemia; history of deep venous thrombosis, pulmonary embolus or cerebrovascular accident; uncontrolled hypertension or known symptomatic heart disease; history of (or suspected) cervical carcinoma, endometrial carcinoma or breast carcinoma; and undiagnosed vaginal bleeding. * Previous history of poor ovarian response (\<4 oocytes retrieved) with a maximal dose of OS (≥300 IU/day) or OHSS, regardless of gonadotropin dose * Known reasons for impaired implantation (i.e. hydrosalpinx, fibroid distorting the endometrial cavity, Asherman's syndrome, thrombophilia or endometrial tuberculosis) * Repeated miscarriages (\>2 previous biochemical pregnancies or \>2 spontaneous miscarriages) * Recurrent implantation failure (\>3 failed cycles with good quality embryos) * PCOS * Untreated thyroid disfunction * Administration of exogenous E2, P4 or gonadotropins in the preceding menstrual cycle * Active female smoking * Ongoing pregnancy * Women who have previously enrolled in the trial * Those unable to comprehend the investigational nature of the proposed study * either male partner or female partner has to receive donor sperm or donor eggs. * Either male partner or female partner has to receive PGD and PGS.
Where this trial is running
Beijing, Beijing Municipality
- Peking Univesity Third Hospital — Beijing, Beijing Municipality, China (Recruiting)
Study contacts
- Study coordinator: Rong Li, M.D.
- Email: roseli001@sina.com
- Phone: +86-010-82265080
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.