title: The PhenX Toolkit pregnancy and birth collections.
abstract: OBJECTIVE
  Pregnancy and childbirth are normal conditions, but complications and adverse outcomes are common. Both genetic and environmental factors influence the course of pregnancy. Genetic epidemiologic research into pregnancy outcomes could be strengthened by the use of common measures, which would allow data from different studies to be combined or compared. Here, we introduce perinatal researchers to the PhenX Toolkit and the Collections related to pregnancy and childbirth.
  
  
  METHODS
  The Pregnancy and Birth Collections were drawn from measures in the PhenX Tooklit. The lead author selected a list of measures for each Collection, which was reviewed by the remaining authors and revised on the basis of their comments. We chose the measures we thought were most relevant for perinatal research and had been linked most strongly to perinatal outcomes.
  
  
  RESULTS
  The Pregnancy and Birth Health Conditions Collection includes 24 measures related to pregnancy and fertility history, maternal complications, and infant complications. The Pregnancy and Birth Outcome Risk Factors Collection includes 43 measures of chemical, medical, psychosocial, and personal factors associated with pregnancy outcomes.
  
  
  CONCLUSIONS
  The biological complexity of pregnancy and its sensitivity to environmental and genomic influences suggest that multidisciplinary approaches are needed to generate new insights or practical interventions. To fully exploit new research methods and resources, we encourage the biomedical research community to adopt standard measures to facilitate pooled or meta-analyses.
authors.affiliation: RTI International, San Francisco, CA, USA. nwhitehead@rti.org
authors.forename: Nedra S
authors.initials: NS
authors.lastname: Whitehead
authors.forename: Jane A
authors.initials: JA
authors.lastname: Hammond
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Williams
authors.forename: Wayne
authors.initials: W
authors.lastname: Huggins
authors.forename: Sonja
authors.initials: S
authors.lastname: Hoover
authors.forename: Carol M
authors.initials: CM
authors.lastname: Hamilton
authors.forename: Erin M
authors.initials: EM
authors.lastname: Ramos
authors.forename: Heather A
authors.initials: HA
authors.lastname: Junkins
authors.forename: William R
authors.initials: WR
authors.lastname: Harlan
authors.forename: Carol J
authors.initials: CJ
authors.lastname: Hogue
mesh_terms: D035843:Biomedical Research; D003625:Data Collection / Q000592:standards; D005260:Female; D016045:Human Genome Project; D006801:Humans; D007223:Infant; D018743:Perinatal Care / Q000592:standards*; D010641:Phenotype; D011247:Pregnancy; D011256:Pregnancy Outcome / Q000235:genetics; D012307:Risk Factors