5Committee on Gynecologic Practice of American College of Obstetricians and Gynecologists, Practice Committee of American Society for Reproductive Medicine. Age-related fertility decline:a committee opinion[J]. Fertil Steril,2008,90(5 Suppl):S154-155.
6Practice Committee of American Society for Reproductive Medicine. Aging and infertility in women[J]. Fertil Steril, 2006, $6(5 Suppl 1 ) : $248-252.
7Heffner JL. Advanced maternal age:How old is too old? [J]. N Engl J Med, 2004, 351( 19): 1927-1929.
8Smith KE, Buyalos RP. The profound impact of patient age on pregnancy outcome after early detection of fetal cardiac activity [J]. Fertil Steril, 1996,65( 1 ) : 35-40.
