When do you take an Ovidrel trigger shot for IUI?
In an IUI cycle, Ovidrel (choriogonadotropin alfa) is typically taken as the “trigger” shot to induce final maturation and ovulation. Most clinics schedule the IUI about 24 to 36 hours after the Ovidrel injection.
That timing is based on the idea that ovulation usually occurs roughly within that window after the trigger, so the sperm is placed in the reproductive tract around the time the egg is released.
How does the clinic decide the exact timing (24 vs 36 hours)?
The exact hour can vary depending on clinic protocol and your monitoring results, especially ultrasound findings (follicle size and count) and sometimes bloodwork. If your follicles are ready and your clinic has a standard schedule, many clinicians use a consistent timing such as:
- IUI once, scheduled for roughly the mid-point of the 24–36 hour window, or
- IUI once closer to one end of the window (commonly around 24 hours) when they want the insemination nearer to the expected ovulation time.
What if my clinic does IUI twice instead of once?
Some clinics perform a “double insemination” to cover the expected ovulation period:
- One IUI dose at about 24 hours after Ovidrel
- A second IUI dose around 36 hours after Ovidrel
This approach is sometimes used when timing certainty is lower or based on prior cycle patterns, but the practice varies by clinic.
What should you do if you’re unsure of your trigger day?
Timing is critical. If you do not have a clear plan from your fertility clinic for the day and hour of the IUI after the Ovidrel shot, call the clinic’s IUI line. Ask for the scheduled IUI appointment time specifically in relation to your trigger (for example, “Is my IUI at 24 or 36 hours after the Ovidrel?”).
Why the timing matters (and what can go wrong)
If the IUI is done too early after Ovidrel, the egg may not be released yet. If it’s done too late, ovulation may have already occurred and the egg’s viable window may be shorter. That is why clinics tie the insemination schedule directly to the trigger shot timing.
If you share what day and time you took (or plan to take) your Ovidrel, and whether your clinic plans one IUI or two, I can help you calculate the typical 24–36 hour window for appointments.