Common Side Effects After Ovidrel Trigger Shot
Ovidrel (choriogonadotropin alfa), a synthetic hCG used to trigger ovulation in fertility treatments like IVF, mimics natural pregnancy hormones. Most side effects stem from this hormone surge and occur within hours to days post-injection. They include:
- Mild injection site reactions: redness, swelling, pain, or itching at the site (affects up to 10-20% of users).
- Headache or dizziness.
- Nausea, vomiting, or abdominal discomfort.
- Breast tenderness or swelling.
- Fatigue or mood changes like irritability.
These typically resolve within 1-2 weeks as hCG levels drop (half-life is about 30 hours).[1][2]
What Happens During the Two-Week Wait
Post-trigger, hCG circulates for 10-14 days, overlapping with early pregnancy symptoms if implantation occurs. This causes overlap confusion:
- Bloating or mild pelvic pain from ovarian enlargement (OHSS risk factor).
- Spotting or light bleeding in some cases.
- Positive pregnancy tests starting 9-11 days post-trigger due to residual hCG, not always viable pregnancy.
False positives decline after day 12; beta hCG blood tests distinguish.[1][3]
Serious Risks and When to Seek Help
Rare but critical issues include:
- Ovarian hyperstimulation syndrome (OHSS): Severe abdominal pain, rapid weight gain (>2 lbs/day), shortness of breath, or urine output drop. Occurs in 1-5% of cycles, higher with high responders.
- Ectopic pregnancy risk elevation due to multiple follicles.
- Allergic reactions: Rash, hives, swelling, or anaphylaxis (very rare).
Contact your doctor immediately for severe symptoms; OHSS may require hospitalization.[2][4]
How Long Do Side Effects Last?
Mild effects peak 24-48 hours post-shot and fade by cycle end (7-14 days). OHSS can persist 1-2 weeks or longer if pregnant. Monitoring via ultrasound reduces risks.[1][3]
Differences from Natural hCG Triggers
Ovidrel is purer than urinary hCG (e.g., Novarel), with fewer batch inconsistencies and lower contamination risk, but side effect profiles are similar. Some report less nausea with Ovidrel.[2][5]
Sources
[1]: Drugs.com - Ovidrel Side Effects
[2]: FDA Label - Ovidrel
[3]: ASRM Guidelines on Trigger Shots
[4]: Mayo Clinic - OHSS
[5]: FertilityIQ - Ovidrel vs. hCG