What is the purpose of a trigger shot with Intravenous (IV) immunoglobulin (Ive is assumed to be IV, but it could also be Intramuscular, however, given the context, IV is more likely)?

From the Research

The most effective timing for a trigger shot with IUI is 42 hours after human chorionic gonadotropin (hCG) injection, as it significantly increases the chances of fertility compared to doing it 36 hours after hCG injection, as shown in a randomized clinical trial 1.

Key Points to Consider

• The trigger shot is typically administered as a single subcutaneous or intramuscular injection of hCG medications like Ovidrel (250 mcg), Pregnyl, or Novarel (5,000-10,000 IU)
• The medication mimics the natural luteinizing hormone (LH) surge that triggers ovulation in a natural cycle
• Some patients may alternatively receive Lupron (leuprolide acetate) as a trigger, particularly those at high risk for ovarian hyperstimulation syndrome
• After the trigger shot, patients may experience mild side effects like injection site soreness, bloating, or breast tenderness

Evidence-Based Recommendations

• A study published in the Journal of family & reproductive health found that doing IUI 42 hours after hCG injection can significantly increase chances of fertility compared to doing it 36 hours after hCG injection 1
• Another study published in the International journal of endocrinology found that the use of GnRH agonist to trigger ovulation in patients undergoing ovulation induction may be considered in patients treated with IUI 2
• However, the most recent and highest quality study, published in 2021, found a trend toward better clinical pregnancy rates with the use of GnRH agonist trigger in IUI cycles with oral ovulogens, although the difference was not found to be statistically significant 3

Clinical Implications

• The timing of the trigger shot is critical, and it must be administered at the exact time specified by the fertility clinic to ensure optimal egg maturity
• Patients should follow their clinic's specific instructions regarding medication storage, injection technique, and post-trigger activities
• Further randomized controlled trials are needed to confirm the findings and determine the best approach for trigger shots with IUI.