[Analysis the original cause of 623 infertility couples to be taken in vitro fertilization in the northwest region of China].
Liu
Kun
K
The Center of Reproductive Medecine Research, The First Hospital of Lanzhou University, Lanzhou 730000, China.
Zhang
Xue-hong
XH
D000328:Adult; D002681:China; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D007246:Infertility / Q000453:epidemiology / Q000209:etiology* / Q000628:therapy*; D008297:Male