Bypassing superovulation steps and proceeding directly to in vitro fertilization (IVF) technology appears to improve pregnancy outcomes for older women who have unexplained infertility, researchers reported at the annual meeting of the American Society for Reproductive Medicine.

This randomized trial found that older women with unexplained infertility were significantly more likely to achieve pregnancy and a live birth if treated immediately with in vitro fertilization rather than stepwise with superovulation techniques first.

Clinical pregnancy was achieved in 21 women in 24.7% of 85 cycles if these women were treated with in vitro fertilization as a first stop, compared with clinical pregnancy in 13 women in 7.3% of 178 cycles in which they were initially treated with superovulation treatments, a statistically significant difference (P=0.0008).

In addition, 13 women (15.3% of cycles) in the immediate in vitro fertilization group took home a baby, compared with 9 women (5.1% of cycles) who were treated at first with superovulation techniques (P=0.017). Most of the women who received superovulation treatments still underwent in vitro fertilization due to pregnancy failure.

"Beginning treatment with immediate in vitro fertilization compared to initial treatments of superovulation results in a significantly higher number of live-born infants and with significantly more couples pregnant, during the initial cycles of treatment," the author said in his oral presentation.

In the population of women who have unexplained infertility, going directly to in vitro fertilization reduced the number of cycles of therapy required to get pregnant and that the majority of their infants will be conceived through in vitro fertilization anyway.