title: Age-specific chlamydial infection among pregnant women in the United States: evidence for updated recommendations.
abstract: BACKGROUND
  In the United States, chlamydia screening has been recommended for all pregnant women by the Centers for Disease Control and Prevention (CDC) but only for pregnant women who are at increased risk by the US Preventive Services Task Force (USPSTF). Very limited evidence, such as age-specific chlamydia positivity in pregnant women, has been used to develop these recommendations.
  
  
  METHODS
  We analyzed data from a large commercial laboratory corporation in the United States in 2013. At the first prenatal visit made by women aged 15 to 44 years for whom a chlamydia test was performed between June 2008 and July 2010, we estimated positivity of chlamydia by age, insurance coverage, geographic region, and test type.
  
  
  RESULTS
  Of 601,001 pregnant women aged 15 to 44 years who had routine prenatal care, 62.9% had private insurance and 32.9% had Medicaid coverage, 60.3% resided in the South region, and 43.2% were aged 15 to 24 years, 26.8% were aged 25 to 29 years, and 19.1% were aged 30 to 34 years. Chlamydia positivity was 3.6% overall, and significantly decreased as age increased (15-19 years: 9.6 %; 20-24 years: 5.2%; 25-29 years: 1.8%; 30-34 years: 0.9%; and 35-44 years: 0.6%; P < 0.05).
  
  
  CONCLUSIONS
  Our findings of higher positivity among younger pregnant women suggest that the yield is likely to be greater from screening younger pregnant women than from screening older pregnant women to identify chlamydia infection. The benefits of harmonizing CDC and USPSTF recommendations for pregnant women could be explored by reviewing age-specific positivity data and estimating the frequency of prenatal adverse health outcomes caused by chlamydia to develop consensus regarding the age limit for pregnant women who should be screened.
authors.affiliation: From the *Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA; and †Laboratory Corporation of America® Holdings, Burlington, NC.
authors.forename: Guoyu
authors.initials: G
authors.lastname: Tao
authors.forename: Karen W
authors.initials: KW
authors.lastname: Hoover
authors.forename: Melinda B
authors.initials: MB
authors.lastname: Nye
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Body
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002690:Chlamydia Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control; D055317:Evidence-Based Practice; D005260:Female; D006801:Humans; D008403:Mass Screening / Q000458:organization & administration; D008484:Medicaid; D017410:Practice Guidelines as Topic; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control; D011295:Prenatal Care / Q000458:organization & administration*; D015995:Prevalence; D012307:Risk Factors; D012725:Sexual Behavior / Q000706:statistics & numerical data*; D014481:United States / Q000453:epidemiology