Storing frozen embryos from first IVF treatment may be an advantage.

Women who conceived their first child via assisted reproductive technology (ART) and returned for a second baby had better than even probability of getting pregnant again.

After six complete cycles, women who recommenced ART treatment with previously frozen embryos had a cumulative live birth rate of 61% to 88%, depending on assumptions made about the likelihood of success in women who dropped out of treatment, reported Georgina Chambers, PhD, of the University of New South Wales in Sydney, Australia, and colleagues.

For women who started in vitro fertilization (IVF) for their second baby with fresh embryos, cumulative live birth rates were between 51% and 70%.

Women who conceived a child via ART, 43% returned to treatment for a subsequent pregnancy.

This is important because most couples want more than one child. And those that had to use IVF to achieve their first baby are likely to need IVF again.

The live birth rate in the first complete cycle was 43.4% for those who used a frozen embryo from the previous treatment, and 31.3% for women who started a new ovarian stimulation cycle. Although cycle-specific live birth rates declined in successive cycles, cumulative live birth rates increased for all age groups up to six cycles.

Among women younger than 30, live birth rates were similar for those who started their second treatment with previously frozen or fresh embryos. Yet for older women, live birth rates were better for those who used frozen embryos.