rates can be increased by the placement of several embryos, at the risk of increasing the chance for multiples.

Because not every IVF cycle that is started will lead to oocyte retrieval or embryo transfer, reports of live birth rates need to specify the denominator, namely, IVF cycles started, IVF retrievals, or embryo transfers. The SART summarised 2008-9 success rates for US clinics for fresh embryo cycles that did not involve donor eggs and gave live birth rates by the age of the prospective mother, with a peak at 41.3% per cycle started