title: Maternal smoking during pregnancy, prematurity and recurrent wheezing in early childhood.
abstract: BACKGROUND
  Prenatal maternal smoking and prematurity independently affect wheezing and asthma in childhood.
  
  
  OBJECTIVE
  We sought to evaluate the interactive effects of maternal smoking and prematurity upon the development of early childhood wheezing.
  
  
  METHODS
  We evaluated 1,448 children with smoke exposure data from a prospective urban birth cohort in Boston. Maternal antenatal and postnatal exposure was determined from standardized questionnaires. Gestational age was assessed by the first day of the last menstrual period and early prenatal ultrasound (preterm < 37 weeks gestation). Wheezing episodes were determined from medical record extraction of well and ill/unscheduled visits. The primary outcome was recurrent wheezing, defined as ≥ 4 episodes of physician documented wheezing. Logistic regression models and zero inflated negative binomial regression (for number of episodes of wheeze) assessed the independent and joint association of prematurity and maternal antenatal smoking on recurrent wheeze, controlling for relevant covariates.
  
  
  RESULTS
  In the cohort, 90 (6%) children had recurrent wheezing, 147 (10%) were exposed to in utero maternal smoke and 419 (29%) were premature. Prematurity (odds ratio [OR] 2.0; 95% confidence interval [CI], 1.3-3.1) was associated with an increased risk of recurrent wheezing, but in utero maternal smoking was not (OR 1.1, 95% CI 0.5-2.4). Jointly, maternal smoke exposure and prematurity caused an increased risk of recurrent wheezing (OR 3.8, 95% CI 1.8-8.0). There was an interaction between prematurity and maternal smoking upon episodes of wheezing (P = 0.049).
  
  
  CONCLUSIONS
  We demonstrated an interaction between maternal smoking during pregnancy and prematurity on childhood wheezing in this urban, multiethnic birth cohort.
authors.affiliation: Division of Allergy and Immunology, Children's Memorial Hospital, Chicago, Illinois 60614, USA.
authors.forename: Rachel G
authors.initials: RG
authors.lastname: Robison
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Lester M
authors.initials: LM
authors.lastname: Arguelles
authors.forename: Xiumei
authors.initials: X
authors.lastname: Hong
authors.forename: Guoying
authors.initials: G
authors.lastname: Wang
authors.forename: Stephanie
authors.initials: S
authors.lastname: Apollon
authors.forename: Anthony
authors.initials: A
authors.lastname: Bonzagni
authors.forename: Kathryn
authors.initials: K
authors.lastname: Ortiz
authors.forename: Colleen
authors.initials: C
authors.lastname: Pearson
authors.forename: Jacqueline A
authors.initials: JA
authors.lastname: Pongracic
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Wang
mesh_terms: D000328:Adult; D001249:Asthma / Q000139:chemically induced / Q000453:epidemiology; D001900:Boston / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D018811:Maternal Exposure; D011247:Pregnancy; D047928:Premature Birth / Q000139:chemically induced / Q000453:epidemiology*; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced / Q000453:epidemiology*; D011446:Prospective Studies; D012135:Respiratory Sounds / Q000209:etiology*; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects; D016216:Ultrasonography, Prenatal; D055815:Young Adult
chemical_list: D014028:Tobacco Smoke Pollution