[Present situation and task of obstetrics].
Dai
Zhong-ying
ZY
Dong
Yue
Y
Duan
Tao
T
D000013:Congenital Abnormalities / Q000517:prevention & control; D005260:Female; D006801:Humans; D008428:Maternal Mortality; D009774:Obstetrics; D011247:Pregnancy