title: Similarities and differences between the risk factors for gestational hypertension and preeclampsia: A population based cohort study in south China.
abstract: OBJECTIVE
  To compare the risk factors for gestational hypertension (GH) and preeclampsia (PE) in the same population, which may provide clues to better understanding of their etiologic mechanisms.
  
  
  METHODS
  We conducted a cohort study in Liuyang, China, during 2010-2011. Twelve potential risk factors were investigated, including maternal age, body mass index at first antenatal visit, gender of newborn, parity, abortion history, smoking history, family history of hypertension, gestational diabetes mellitus, pregnancy complications of diabetes mellitus/renal disease/cardiac disease, reproductive tract infection, season of delivery, and district level average per capita income. Logistic regression were used to estimate odds ratios for potential risk factors.
  
  
  RESULTS
  Of 6223 pregnancies, 1.8% was complicated by PE, and 5.4% by GH. Maternal age older than 35, body mass index above 24, and pregnancy complicated with gestational diabetes mellitus increased the risk of both PE and GH, while with different effect sizes. Primiparity and deliver in winter and spring (compared with summer delivery) were risk factors for GH only. Pregnancy complicated with diabetes mellitus/renal disease/cardiac disease was risk factor for PE only. Significantly lower risk of GH was observed for women younger than 25 or with low body mass index in the first trimester. Mothers carrying a male fetus were more likely to develop PE.
  
  
  CONCLUSIONS
  Risk factors for GH and PE were not exactly the same. Underling those differences might be their different etiology and mechanism. To confirm the similarities and differences been found in single study, it is important to conduct investigation in other population.
authors.affiliation: School of Public Health, Central South University, 90 Xiangya Road, Changsha, Hunan, China. Electronic address: li.xunxx@hotmail.com.
authors.forename: Xun
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Public Health, Central South University, 90 Xiangya Road, Changsha, Hunan, China. Electronic address: tanhz99@qq.com.
authors.forename: Hongzhuan
authors.initials: H
authors.lastname: Tan
authors.affiliation: School of Public Health, Central South University, 90 Xiangya Road, Changsha, Hunan, China. Electronic address: monaxinhuang@qq.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Huang
authors.affiliation: Liuyang Municipal Hospital of Maternal and Child Health, 53 Beizheng North Road, Liuyang, Hunan, China. Electronic address: 563999542@qq.com.
authors.forename: Shujin
authors.initials: S
authors.lastname: Zhou
authors.affiliation: School of Public Health, Central South University, 90 Xiangya Road, Changsha, Hunan, China. Electronic address: 583534035@qq.com.
authors.forename: Shimin
authors.initials: S
authors.lastname: Hu
authors.affiliation: School of Public Health, Central South University, 90 Xiangya Road, Changsha, Hunan, China. Electronic address: 646829625@qq.com.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Public Health, Central South University, 90 Xiangya Road, Changsha, Hunan, China. Electronic address: 787762507@qq.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.affiliation: School of Public Health, Central South University, 90 Xiangya Road, Changsha, Hunan, China; Criminal Investigation Division, Changsha Public Security Bureau, Hunan, China. Electronic address: sean-6868@163.com.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.affiliation: OMNI Research Group, Department of Obstetrics and Gynecology, University of Ottawa, 501 Smyth Road, Box 241, Ottawa, Ontario K1H 8L6, Canada. Electronic address: swwen@ohri.ca.
authors.forename: Shi Wu
authors.initials: SW
authors.lastname: Wen
mesh_terms: D000328:Adult; D001794:Blood Pressure; D016009:Chi-Square Distribution; D002681:China / Q000453:epidemiology; D005260:Female; D005865:Gestational Age; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D015994:Incidence; D016015:Logistic Models; D015999:Multivariate Analysis; D016017:Odds Ratio; D011225:Pre-Eclampsia / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D011247:Pregnancy; D018570:Risk Assessment; D012307:Risk Factors; D055815:Young Adult
keywords: Gestational hypertension; Preeclampsia; Pregnancy induced hypertension; Risk factors