Typical Timing of Ovulation After Ovidrel
Ovidrel (choriogonadotropin alfa), a synthetic hCG injection used in fertility treatments, triggers ovulation about 36 to 40 hours after administration in most women.[1] This converts to roughly 1.5 to 2 days (or 1-2 full days, depending on exact timing). Doctors often schedule timed intercourse or insemination 24-36 hours post-injection to align with the egg release.
Factors That Affect Timing
Individual response varies based on age, ovarian reserve, follicle size (ideally 18-24 mm at trigger), and protocol (e.g., IVF vs. IUI). Some ovulate as early as 24 hours or as late as 48 hours.[2] Ultrasound monitoring confirms the exact moment via follicle collapse.
How to Confirm Ovulation
- Ultrasound: Follicles shrink post-ovulation; check 36-48 hours after Ovidrel.
- LH surge tests: Less reliable post-hCG due to mimicry.
- Progesterone blood test: Levels rise >3 ng/mL days after trigger.
Avoid home OPKs immediately after, as hCG lingers 7-10 days.[3]
What If Ovulation Is Delayed or Absent?
Up to 10-20% of cycles show delayed (>48 hours) or no ovulation, often from poor follicle maturity or overstimulation risks like OHSS.[4] Repeat trigger or cycle cancellation may follow. Consult your REI specialist for personalized tracking.
Intercourse and Conception Tips
Aim for sex every 12-24 hours starting 24 hours post-Ovidrel through 48 hours. Sperm survives 3-5 days; egg window is 12-24 hours. Success rates: ~20-30% per cycle in IUI, higher in IVF.[1][5]
[1]: FDA Label for Ovidrel
[2]: ASRM Practice Committee Guidelines
[3]: FertilityIQ on hCG Triggers
[4]: Human Reproduction Update Study
[5]: CDC ART Success Rates