From the FDA Drug Label
Induction of ovulation and pregnancy in the anovulatory, infertile woman in whom the cause of anovulation is secondary and not due to primary ovarian failure and who has been appropriately pretreated with human menotropins. 5,000 to 10,000 USP Units one day following the last dose of menotropins.
The optimal time for the Ovidrel shot (choriogonadotropin alfa) prior to IUI is one day following the last dose of menotropins. The recommended dosage is 5,000 to 10,000 USP Units 1.
From the Research
The optimal time for an Ovidrel (choriogonadotropin alfa) trigger shot prior to intrauterine insemination (IUI) is typically 24 hours before the scheduled IUI procedure for patients with unexplained infertility, as this timing has been associated with significantly better clinical pregnancy rates in these patients. This recommendation is based on the most recent and highest quality study available, which found that IUI performed 24 hours after ovulation triggered by hCG injection resulted in higher clinical pregnancy rates for patients with unexplained infertility 2. The study, published in 2017, compared the clinical pregnancy rates of IUI procedures performed at 24 hours and 36 hours after hCG trigger in patients with polycystic ovary syndrome (PCOS) and unexplained infertility. While the study found no significant difference in clinical pregnancy rates for PCOS patients, it did find a significant improvement in clinical pregnancy rates for patients with unexplained infertility when IUI was performed 24 hours after hCG trigger.
Key Considerations
- The timing of the Ovidrel trigger shot is critical to maximize the chances of fertilization and pregnancy.
- Sperm can survive in the female reproductive tract for about 24-48 hours, while eggs remain viable for only 12-24 hours after ovulation.
- Individual patient factors, such as follicle size and hormone levels, may influence the optimal timing of the Ovidrel trigger shot.
- Patients should follow their clinic's specific instructions regarding injection technique, storage of medication, and any activity restrictions following the trigger shot.
Evidence Summary
- A 2017 study published in the Journal of the Chinese Medical Association found that IUI performed 24 hours after hCG trigger resulted in higher clinical pregnancy rates for patients with unexplained infertility 2.
- A 2025 Cochrane review found that gonadotropins, including Ovidrel, probably result in more live births and clinical pregnancies than continued clomiphene citrate in women with PCOS who do not ovulate or conceive on clomiphene citrate or letrozole 3.
- Earlier studies, such as those published in 1997,2004, and 2006, found no significant difference in clinical pregnancy rates between different timing strategies for IUI 4, 5, 6. However, these studies were superseded by the more recent and higher quality studies mentioned above.