Does Ovidrel Cause Twins?
Ovidrel (choriogonadotropin alfa), a recombinant hCG injection used to trigger ovulation in fertility treatments like IVF or IUI, does not directly cause twins. It mimics the natural LH surge to release one or more mature eggs from the ovaries, but twin pregnancies result from multiple eggs fertilizing and implanting, not the trigger shot itself.[1][2]
How Does Ovidrel Fit into Multiple Pregnancies?
In fertility protocols, gonadotropins like Gonal-F or Follistim stimulate the ovaries to produce multiple follicles (often 2–3 or more). Ovidrel then triggers their release. If two or more eggs are fertilized, twins (or higher-order multiples) can occur. Studies show multifollicular development, not the trigger, drives this risk—Ovidrel simply finalizes ovulation.[3][4]
What Are the Actual Twin Rates with Ovidrel?
Clinical data from Ovidrel trials report twin rates of 20–30% in fresh IVF cycles, comparable to urinary hCG triggers like Pregnyl. This aligns with IVF averages (25–35% twins), driven by embryo transfer practices rather than the drug. Singleton rates exceed 60%.[1][5]
| Trigger Type | Twin Rate in IVF (approx.) | Source |
|--------------|-----------------------------|--------|
| Ovidrel (recombinant hCG) | 22–28% | [1][5] |
| Pregnyl (urinary hCG) | 24–30% | [3] |
| GnRH agonist (e.g., Lupron) | 10–15% (lower multiples) | [4] |
Why Do Fertility Drugs Overall Increase Twins?
Superovulation from upstream follicle-stimulating drugs raises multiple egg release odds to 20–40%, far above natural conception (1–2% twins). Ovidrel users often have 2–3 embryos transferred, boosting implantation chances. OHSS risk ties to follicle count, indirectly linking to multiples.[2][6]
Can You Reduce Twin Risk with Ovidrel Cycles?
Yes—use single embryo transfer (SET), now standard in many clinics, dropping twins to under 5%. Mild stimulation protocols or natural-cycle IVF limit follicles to one. GnRH triggers (vs. hCG like Ovidrel) cut OHSS and may lower multiples slightly.[4][7]
Patient Experiences and Side Effects Linked to Multiples?
Forums and studies note no unique twin causation by Ovidrel, but symptoms like bloating mimic early multiples. Common side effects (headache, injection pain) occur in 10–20%; multiples raise miscarriage/OHSS risks. Consult REI for personalized odds.[5][8]
Sources:
[1] Ovidrel Prescribing Information (FDA)
[2] ASRM Fertility Treatment Guidelines
[3] Cochrane Review: hCG Triggers in IVF
[4] Human Reproduction Update: Triggers and Multiples
[5] Fertility and Sterility Journal: Ovidrel Outcomes
[6] CDC ART Success Rates
[7] ESHRE Guidelines on Ovarian Stimulation
[8] Drugs.com: Ovidrel Side Effects