Intrauterine insemination (IUI) is a fertility treatment that involves placing sperm directly into the uterus to increase the chances of fertilization. One common question among couples undergoing IUI is about the possibility of conceiving multiples—twins, triplets, or more.
Why Does IUI Increase the Chance of Multiples?
The likelihood of multiple pregnancies with IUI is primarily influenced by:
- Ovarian Stimulation: Many IUI cycles involve fertility medications like clomiphene citrate or gonadotropins to stimulate the ovaries and increase the number of mature eggs released. More eggs increase the chance of multiple fertilizations.
- Number of Eggs Released: When multiple eggs are ovulated, the chance of conceiving twins or higher-order multiples rises.
What Are the Actual Chances?
- The multiple pregnancy rate after IUI varies but is generally around 10-20% in stimulated cycles.
- The chances of twins are most common, while triplets or higher-order multiples are less frequent.
- In natural (unstimulated) IUI cycles, the multiple pregnancy rate is much lower, closer to natural conception rates (~1-2%).
Managing the Risk of Multiples
Fertility specialists carefully monitor ovarian response during IUI cycles to minimize the risk of high-order multiples due to the increased risks associated with multiple pregnancies for both mother and babies. Treatment protocols may be adjusted based on ultrasound findings and hormone levels.
Conclusion
While IUI increases the chances of conceiving multiples compared to natural conception, the risk is moderate and usually manageable with proper medical supervision. Couples should discuss the potential for multiple pregnancies with their fertility specialist to understand what to expect and how risks are minimized during treatment.