title: Kaiser Permanente Northern California pregnancy database: Description and proof of concept study.
abstract: We describe the establishment of a dynamic database linking mothers to newborns with the goal of studying vaccine safety in both pregnant women and their children and provide results of a study utilizing this database as a proof of concept.
  
  
  
  All Kaiser Permanente Northern California (KPNC) live births and their mothers were eligible for inclusion in the pregnancy database. We used the medical record number (MRN), a unique identifier, to retrieve information about events that occurred during the pregnancy and at delivery and linked this same MRN to newborns for post-partum follow up. We conducted a retrospective cohort study to evaluate the association between receipt of tetanus, diphtheria and acellular pertussis (Tdap) vaccine during pregnancy and fever 0-3days after the first dose of diphtheria tetanus and acellular pertussis (DTaP) vaccine in the infant. The study included infants who were born at ⩾37weeks gestation from January 1, 2009 - October 1, 2015 and who received their first DTaP vaccine between 6 and 10weeks of age. We utilized diagnostic codes from inpatient, emergency department, outpatient clinics, and telephone calls. We identified fever using ICD 9 code 780.6, recorded temperature ⩾101 degree Fahrenheit, or parental report.
  
  
  
  The database contained the starting and ending date of each pregnancy and basic demographic characteristics of mothers and infants. There were 859,699 women and 873,753 children in the database as of January 2016. The proof of concept study included 148,699 infants. In a multivariable logistic regression analysis, Tdap vaccination during pregnancy was not associated with infant fever 0-3daysafter first dose of DTaP (adjusted odds ratio=0.92, 95% CI 0.82-1.04).
  
  
  
  The KPNC pregnancy database can be used for studies investigating exposure during pregnancy and outcomes in mothers and/or infants, particularly monitoring vaccine safety and effectiveness.
authors.affiliation: Kaiser Permanente Vaccine Study Center, 1 Kaiser Plaza, 16B, Oakland, CA 94612, USA. Electronic address: ousseny.x.zerbo@kp.org.
authors.forename: Ousseny
authors.initials: O
authors.lastname: Zerbo
authors.affiliation: Kaiser Permanente Vaccine Study Center, 1 Kaiser Plaza, 16B, Oakland, CA 94612, USA.
authors.forename: Berwick
authors.initials: B
authors.lastname: Chan
authors.affiliation: Kaiser Permanente Vaccine Study Center, 1 Kaiser Plaza, 16B, Oakland, CA 94612, USA.
authors.forename: Kristin
authors.initials: K
authors.lastname: Goddard
authors.affiliation: Kaiser Permanente Vaccine Study Center, 1 Kaiser Plaza, 16B, Oakland, CA 94612, USA.
authors.forename: Ned
authors.initials: N
authors.lastname: Lewis
authors.affiliation: National Vaccine Program Office, Office of the Assistant Secretary for Health, US Department of Health and Human Services, USA.
authors.forename: Karin
authors.initials: K
authors.lastname: Bok
authors.affiliation: Kaiser Permanente Vaccine Study Center, 1 Kaiser Plaza, 16B, Oakland, CA 94612, USA.
authors.forename: Nicola P
authors.initials: NP
authors.lastname: Klein
authors.affiliation: Kaiser Permanente Vaccine Study Center, 1 Kaiser Plaza, 16B, Oakland, CA 94612, USA.
authors.forename: Roger
authors.initials: R
authors.lastname: Baxter
mesh_terms: D000328:Adult; D002140:California; D015331:Cohort Studies; D016208:Databases, Factual; D004165:Diphtheria / Q000517:prevention & control; D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007348:Insurance, Health / Q000706:statistics & numerical data*; D016015:Logistic Models; D010567:Pertussis Vaccine / Q000008:administration & dosage / Q000009:adverse effects; D049590:Postpartum Period; D011247:Pregnancy; D037841:Pregnant People; D000075082:Proof of Concept Study; D012189:Retrospective Studies; D013742:Tetanus / Q000517:prevention & control; D014611:Vaccination / Q000706:statistics & numerical data; D014612:Vaccines / Q000008:administration & dosage / Q000009:adverse effects*; D014917:Whooping Cough / Q000517:prevention & control; D055815:Young Adult
chemical_list: D022681:Diphtheria-Tetanus-acellular Pertussis Vaccines; D010567:Pertussis Vaccine; D014612:Vaccines
keywords: DTaP; Infant fever; Pregnancy database; Tdap; Vaccination