Strategies to reduce multiple pregnancies due to ovulation stimulation

Objective

To review factors associated with high-order multiple births (HOMB) due to ovulation induction (OI) and the efficacy of strategies to reduce their occurrence.

Design

Retrospective analysis of published studies of OI with intrauterine insemination (IUI) where patient and cycle characteristics were fully documented.

Result(s)

High-order multiple pregnancies (HOMP) were positively related to use of high doses of gonadotropin, number of 7–10 mm preovulatory follicles, and E₂, and inversely related to age and number of treatment cycles. Strategies successful in reducing HOMP include: use of clomiphene (CC) before gonadotropins, minimal gonadotropin doses, cancellation for more than three follicles >10–15 mm, and aspiration of excess follicles. Depending on the strategy used, 5%–20% of cycles may be canceled but HOMP rates can be less than 2% and pregnancy rates can average 10%–20% per cycle. Pregnancy rates per patient need not be reduced if low doses are continued for 4–6 cycles.

Conclusion(s)

High-order multiple pregnancies due to OI can be reduced to 2% or less by less aggressive stimulation without reducing overall chances of pregnancy for most patients.

Key Words: Clomiphene citrate, controlled ovarian hyperstimulation, high-order multiple birth (HOMB), high-order multiple pregnancy (HOMP), intrauterine insemination, ovulation induction (OI), preovulatory follicle number