title: Live birth sex ratio after in vitro fertilization and embryo transfer in China--an analysis of 121,247 babies from 18 centers.
abstract: In order to study the impact of procedures of IVF/ICSI technology on sex ratio in China, we conducted this multi-center retrospective study including 121,247 babies born to 93,895 women in China. There were 62,700 male babies and 58,477 female babies, making the sex ratio being 51.8% (Male: Female  = 107:100). In univariate logistic regression analysis, sex ratio was imbalance toward females of 50.3% when ICSI was preformed compared to 47.7% when IVF was used (P<0.01). The sex ratio in IVF/ICSI babies was significantly higher toward males in transfers of blastocyst (54.9%) and thawed embryo (52.4%) when compared with transfers of cleavage stage embryo (51.4%) and fresh embryo (51.5%), respectively. Multiple delivery was not associated with sex ratio. However, in multivariable logistic regression analysis after controlling for related factors, only ICSI (adjusted OR =  .90, 95%CI: 0.88-0.93; P<0.01) and blastocyst transfer (adjusted OR = 1.14, 95% CI: 1.09-1.20; P<0.01) were associated with sex ratio in IVF/ICSI babies. In conclusion, the live birth sex ratio in IVF/ICSI babies was influenced by the use of ICSI, which may decrease the percentage of male offspring, or the use of blastocyst transfer, which may increase the percentage of male offspring.
authors.affiliation: Reproductive Medicine Center, First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China.
authors.forename: Zhiqin
authors.initials: Z
authors.lastname: Bu
authors.affiliation: Center for Reproductive Medicine, Provincial Hospital Affiliated to Shandong University, Jinan, People's Republic of China.
authors.forename: Zi-Jiang
authors.initials: ZJ
authors.lastname: Chen
authors.affiliation: Chongqing Reproductive and Genetics Institute, Chongqing Obstetrics and Gynecology Hospital, Chongqing, People's Republic of China.
authors.forename: Guoning
authors.initials: G
authors.lastname: Huang
authors.affiliation: Reproductive Medicine Center, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, People's Republic of China.
authors.forename: Hanwang
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Reproductive Medicine Centre, Women and Children Hospital of Jiangxi Province, Nanchang, People's Republic of China.
authors.forename: Qiongfang
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Reproductive Medicine Center, First People's Hospital of Yunnan Province, Kunming, People's Republic of China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Reproductive Medicine Center, Maternal and Child Health Care Hospital of Shaanxi Province, Xi'an, People's Republic of China.
authors.forename: Juanzi
authors.initials: J
authors.lastname: Shi
authors.affiliation: Reproductive Medicine Center, First Affiliated Hospital of Sun Yat-Sen University, Guangdong, People's Republic of China.
authors.forename: Yanwen
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Reproductive Medicine Center, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Songying
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Reproductive Medicine Center, Henan Provincial People's Hospital, Zhengzhou, People's Republic of China.
authors.forename: Cuilian
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Reproductive Medicine Center, Renji Hospital, Shanghai Jiaotong University, Shanghai, People's Republic of China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Reproductive Medicine Center, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Reproductive Medicine Center, Affiliated Hospital of Hainan Medical College, Haikou, People's Republic of China.
authors.forename: Yuanhua
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academic of Medical Sciences, Beijing, People's Republic of China.
authors.forename: Zhengyi
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Reproductive Medicine Center, Maternal and Children's Health Hospital of Fujian Province, Fuzhou, People's Republic of China.
authors.forename: Yuefan
authors.initials: Y
authors.lastname: Kang
authors.affiliation: Reproductive Medicine Center, Boai Hospital of Zhongshan, Zhongshan, People's Public of China.
authors.forename: Riran
authors.initials: R
authors.lastname: Wu
authors.affiliation: Reproductive Medicine Center, Women and Children's Hospital of Shanxi Province, Taiyuan, People's Republic of China.
authors.forename: Xueqing
authors.initials: X
authors.lastname: Wu
authors.affiliation: Reproductive Medicine Center, Nanjing Drum Tower Hospital, Nanjing University, Nanjing, People's Republic of China.
authors.forename: Haixiang
authors.initials: H
authors.lastname: Sun
authors.affiliation: Reproductive Medicine Center, First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China.
authors.forename: Yingpu
authors.initials: Y
authors.lastname: Sun
mesh_terms: D001755:Blastocyst / Q000166:cytology; D002681:China; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D050498:Live Birth; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D011247:Pregnancy; D012189:Retrospective Studies; D012744:Sex Ratio; D020554:Sperm Injections, Intracytoplasmic