title: Combined effects of prenatal medication use and delivery type are associated with eczema at age 2 years.
abstract: BACKGROUND
  Separately, prenatal antibiotics and Caesarian delivery have been found to be associated with increased risk of allergic diseases. It is not clear whether these factors may modify the effect of each other.
  
  
  OBJECTIVE
  To assess whether the associations between delivery types and eczema, sensitization and total IgE at age 2 years were modified by maternal use of prenatal medications.
  
  
  METHODS
  Prenatal charts of women enrolled in the WHEALS birth cohort were reviewed for delivery mode and medications prescribed and administered throughout their entire pregnancy, including systemic antibiotics and vaginally applied antifungal medications. The associations between the delivery mode and select medications and, eczema, sensitization (≥ 1 of 10 allergen-specific IgE ≥ 0.35 IU/mL) and total IgE at age 2 years were assessed.
  
  
  RESULTS
  There was a lower risk of eczema among vaginally vs. c-section born children (relative risk adjusted for race = aRR = 0.77, 95% CI 0.56, 1.05). Although not statistically significantly different, this association was stronger among the subset of children born vaginally to a mother who did not use systemic antibiotics or vaginal antifungal medications (aRR = 0.69, 95% CI 0.44, 1.08) compared to those born vaginally to mothers who used systemic antibiotics or vaginal antifungals (aRR = 0.81, 95% CI 0.57, 1.14). A protective association between vaginal birth and sensitization (aRR = 0.86, 95% CI 0.72, 1.03) was similar for those children born vaginally to a mother who did not (aRR = 0.87, 95% CI 0.69, 1.10) and who did (RR = 0.85, 95% CI 0.70, 1.04) use systemic antibiotics or vaginal antifungal medications. There were no associations with total IgE.
  
  
  CONCLUSIONS
  Children born vaginally had lower risk of eczema and sensitization compared with those born via c-section; however, the protective association with eczema may be slightly weakened when mothers took systemic antibiotics or vaginally applied medications during pregnancy.
authors.affiliation: Department of Public Health Sciences, Henry Ford Hospital, Detroit, MI, USA.
authors.forename: G
authors.initials: G
authors.lastname: Wegienka
authors.forename: S
authors.initials: S
authors.lastname: Havstad
authors.forename: E M
authors.initials: EM
authors.lastname: Zoratti
authors.forename: H
authors.initials: H
authors.lastname: Kim
authors.forename: D R
authors.initials: DR
authors.lastname: Ownby
authors.forename: C C
authors.initials: CC
authors.lastname: Johnson
mesh_terms: D000328:Adult; D000367:Age Factors; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000009:adverse effects; D002585:Cesarean Section / Q000009:adverse effects; D002675:Child, Preschool; D036861:Delivery, Obstetric / Q000379:methods; D004485:Eczema / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D008297:Male; D018811:Maternal Exposure / Q000009:adverse effects*; D008824:Michigan / Q000453:epidemiology; D016017:Odds Ratio; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012306:Risk; D013292:Streptococcus agalactiae / Q000276:immunology
chemical_list: D000890:Anti-Infective Agents; D007073:Immunoglobulin E
keywords: IgE; antibiotics; antifungal; c-section; eczema; microbiome; prenatal