von Wolff M, et al. - In view of the controversies regarding the patients recommended to undergo natural cycle IVF (NC-IVF), researchers sought to define objective prognostic criteria which are already known at the time of counseling. They performed a retrospective observational study with 201 couples (age 34.7 ± 4.1) undergoing 311 NC-IVF treatments with 201 transfers, corresponding to a transfer rate of 65.3%. Observations revealed that pregnancy rate and live birth rates per first cycle were 21.9% and 13.2%, respectively and were correlated negatively with the duration of infertility. Further, they identified a negative correlation of live birth rate but not of pregnancy rate with increasing female age. Based on these findings, they recommend NC-IVF especially for women with short duration of infertility and young age. However, older women and those with long duration of infertility are not identified to be the best candidates for this technique.