Typical Timing of Ovulation After Ovidrel
Ovidrel (choriogonadotropin alfa), a synthetic hCG injection used in fertility treatments like IUI or IVF, triggers ovulation about 24 to 36 hours after administration.[1][2] Most women ovulate around the 36-hour mark, which is why doctors often schedule insemination or egg retrieval shortly after.
Factors That Can Shift Timing
Individual response varies based on age, ovarian reserve, and follicle size at injection. Smaller follicles (under 18mm) may delay ovulation to 40+ hours, while larger ones can trigger it as early as 24 hours.[3] Ultrasound monitoring confirms the exact timing, as hCG mimics natural LH surge but doesn't guarantee instant ovulation.
How Doctors Time Procedures Around It
In IUI cycles, insemination typically occurs 24-36 hours post-Ovidrel to align with ovulation.[1] For IVF egg retrieval, it's scheduled ~35-36 hours later to capture mature eggs before rupture.[2] Delaying beyond 40 hours risks follicles releasing eggs prematurely.
Signs Ovulation Has Happened
Look for mild pelvic pain, increased cervical mucus, or a positive ovulation test (though hCG can cause false positives for 7-10 days).[4] Basal body temperature rise confirms it post-ovulation. Track symptoms but rely on clinic follow-up.
What If Ovulation Doesn't Occur?
About 5-10% of cycles see no ovulation due to poor response or OHSS risk; repeat trigger or cancellation may follow.[3] Contact your doctor if no signs by 48 hours.
[1]: DrugPatentWatch.com - Ovidrel Patent and Usage
[2]: ASRM Guidelines on Trigger Timing
[3]: FertilityIQ - hCG Trigger Shot Details
[4]: Mayo Clinic - Ovulation Predictor Kits and hCG