title: [Effects related to HBeAg status and mode of delivery as well as the interactions on intrauterine transmission among HBsAg-positive mothers].
abstract: OBJECTIVE
  To investigate the relationship between HBeAg status, mode of delivery and intrauterine transmission of the HBsAg-positive mothers as well as their interactions.
  
  
  METHODS
  A total of 344 HBsAg-positive pregnant women and their infants were enrolled in this study. The mothers were recruited from the Third People's Hospital of Taiyuan, from July 2011 to January 2013. Serum HBV-M and HBV DNA were measured using the electro-chemiluminescence immune-assay (ECLIA) kits and fluorescene quantitative polymerase chain reaction (FQ-PCR) assay, respectively. Univariate analysis and unconditional logistic regression analysis were used to explore the risk factors on intrauterine transmission.
  
  
  RESULTS
  Among 344 neonates born to HBsAg-positive mothers, 42 were validated as HBV intrauterine transmitted, with the rate of intrauterine transmission as 12.21% (42/344). The rates of intrauterine transmission among HBeAg-positive and HBeAg-negative mothers were 18.52% (30/162) and 6.59% (12/182), respectively. The rates of intrauterine transmission were 22.22% (34/153) and 4.19% (8/191) in the groups of vaginal birth or caesarean delivery, respectively. RESULTS from unconditional logistic regression analysis showed that after adjusting the confounding factors, HBeAg-positive mothers (OR=3.003, 95% CI: 1.368-6.593) and vaginal birth (OR=7.333, 95% CI: 3.108-17.302) might serve as the risk factors for the HBV intrauterine transmission. Data from the interaction analysis showed that there were additive interactions [relative excess risk due to interaction (RERI) as 14.229; the attributable proportion (AP) due to interaction as 0.587; the synergy index (SI) as 2.579] and multiplicative interaction (OR=1.084, 95%CI: 0.720-1.632) between HBeAg status and the modes of delivery.
  
  
  CONCLUSIONS
  Vaginal birth and HBeAg-positive might serve as the risk factors for HBV intrauterine transmission. There also appeared additive interactions between HBeAg status and the mode of delivery.
authors.affiliation: Department of Epidemiology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: H X
authors.initials: HX
authors.lastname: Wen
authors.affiliation: Department of Epidemiology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: F
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: T
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Epidemiology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Epidemiology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: X F
authors.initials: XF
authors.lastname: Wang
authors.affiliation: Department of Epidemiology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: X X
authors.initials: XX
authors.lastname: Xu
authors.affiliation: Department of Epidemiology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Z D
authors.initials: ZD
authors.lastname: Fu
authors.affiliation: Department of Epidemiology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: J
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Epidemiology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: L R
authors.initials: LR
authors.lastname: Zhang
authors.affiliation: Department of Toxicology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Obstetrics and Gynecology, the Third People's Hospital of Taiyuan, Taiyuan 030001, China.
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Epidemiology, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: S P
authors.initials: SP
authors.lastname: Wang
mesh_terms: D002585:Cesarean Section; D005260:Female; D006509:Hepatitis B; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D009035:Mothers; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious; D012307:Risk Factors
chemical_list: D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens