Accelerated decline in pregnancy rate after fertilization and embryo transfer in 35-41-year-old women: 15 years' experience in the Okinawa Islands, Japan.

To describe 15 years of fertilization and embryo transfer (IVF-ET) treatment at University Hospital, with special reference to a potential association between pregnancy rate and patient age. A retrospective analysis of 2355 IVF-ET cycles carried out in 789 patients was undertaken. The main outcome measures were ovarian response, fertilization rate and pregnancy rate. Pregnancy rates in ET cycles carried out in women aged between 23 and 46 years fell significantly with patient age, with a more rapid decline after 35 years and particularly between 35 and 41 years. Almost all laboratory findings were significantly worse with increased patient age, although fertilization rate did not drop with age. The spontaneous abortion rate increased drastically with age and the vast majority of abortions resulted from chromosomal abnormality. It is essential to provide infertile women with practical and reliable information on the age-associated pregnancy rate for appropriate counseling and to encourage them to seek IVF-ET treatment at an earlier age. (Reprod Med Biol 2006; : 51-57).