Risk factors for preterm birth: a prospective cohort study
YE Chang-Xiang, CHEN Sheng-Bao, WANG Ting-Ting, ZHANG Sen-Mao, QIN Jia-Bi, CHEN Li-Zhang
CJCP . 2021, (12): 1242 -1249 .  DOI: 10.7499/j.issn.1008-8830.2108015