title: Trajectories of length, weight, and bone mineral density among preterm infants during the first 12 months of corrected age in China.
abstract: BACKGROUND
  Limited evidence has been provided on the trajectories of length, weight, and bone mineral density (BMD) among preterm infants in early life in Asian countries.
  
  
  METHODS
  We conducted a longitudinal study, which included 652 late preterm (gestational age: 34-36.9 weeks), 486 moderate preterm (32-33.9), 291 very preterm (28-31.9), 149 extremely preterm infants (≤ 28.9) and 1434 full-term peers (≥ 37) during the first 12 months of corrected age in Wuhan, China. Weight and length were measured at birth, once randomly before term, and every month thereafter. BMD was examined at 3, 6, 9 and 12 months using dual-energy X-ray absorptiometry.
  
  
  RESULTS
  From birth to 12 months of corrected age, growth peaks in length and weight were observed at 1-3 months among preterm infants. No catch-up growth in length, weight, and BMD was observed among preterm infants. However, accelerated growth in length, weight, and BMD was found. Among extremely preterm infants, relative to full-term infants, length was -6.77 cm (95% CI: -7.14, -6.40; P for trend < 0.001) lower during the first 12 months; weight was -1.23 kg (-1.33, -1.13; P for trend < 0.001) lower; and BMD was -0.070 g/cm(2)(-0.087, -0.053; P for trend < 0.001) lower; however, average growth rates of these measures were higher (Ps < 0.05). Small gestational age and low birth weight were independently associated with lower length, weight, and BMD.
  
  
  CONCLUSIONS
  Growth peaks in length and weight among preterm infants were observed at 1-3 months. No catch-up growth in length, weight, and BMD was observed, however, there was accelerated growth in length, weight, and BMD.
authors.affiliation: Department of Child Health Care, Hubei Maternal and Child Health Hospital, Wuhan, Hubei, 430070, China. clearair00@163.com.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Nutrition, Harvard School of Public Health, 655 Huntington Ave, Boston, MA, 02115, USA. mid829@mail.harvard.edu.
authors.forename: Ming
authors.initials: M
authors.lastname: Ding
authors.affiliation: Department of Child Health Care, Hubei Maternal and Child Health Hospital, Wuhan, Hubei, 430070, China. huzubin@hotmail.com.
authors.forename: Zubin
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Department of Child Health Care, Hubei Maternal and Child Health Hospital, Wuhan, Hubei, 430070, China. daiqiong74@163.com.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Dai
authors.affiliation: Department of Nutrition, Harvard School of Public Health, 655 Huntington Ave, Boston, MA, 02115, USA. ambikasatija@gmail.com.
authors.forename: Ambika
authors.initials: A
authors.lastname: Satija
authors.affiliation: Department of Child Health Care, Hubei Maternal and Child Health Hospital, Wuhan, Hubei, 430070, China. mingding517@gmail.com.
authors.forename: Aiqin
authors.initials: A
authors.lastname: Zhou
authors.affiliation: Department of Child Health Care, Hubei Maternal and Child Health Hospital, Wuhan, Hubei, 430070, China. hwxys@hotmail.com.
authors.forename: Yusong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Child Health Care, Hubei Maternal and Child Health Hospital, Wuhan, Hubei, 430070, China. xaken@sina.com.
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Nutrition, Harvard School of Public Health, 655 Huntington Ave, Boston, MA, 02115, USA. nhbfh@channing.harvard.edu.|Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA. nhbfh@channing.harvard.edu.|Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA. nhbfh@channing.harvard.edu.
authors.forename: Frank B
authors.initials: FB
authors.lastname: Hu
authors.affiliation: Department of Child Health Care, Hubei Maternal and Child Health Hospital, Wuhan, Hubei, 430070, China. xuhaiqing9@126.com.
authors.forename: Haiqing
authors.initials: H
authors.lastname: Xu
mesh_terms: D015502:Absorptiometry, Photon; D001827:Body Height; D001835:Body Weight; D015519:Bone Density; D002681:China; D005865:Gestational Age; D006801:Humans; D062071:Infant, Extremely Premature / Q000254:growth & development; D007234:Infant, Premature / Q000254:growth & development*; D008137:Longitudinal Studies