title: Prevalence of uterine leiomyomas in the first trimester of pregnancy: an ultrasound-screening study.
abstract: OBJECTIVE
  To estimate the proportion of pregnant women with one or more leiomyomas detected by research-quality ultrasound screening in the first trimester, to describe the size and location of leiomyomas identified, and to report variation in prevalence by race/ethnicity.
  
  
  METHODS
  Within an ongoing prospective cohort, we conducted 4,271 first-trimester or postmiscarriage ultrasound examinations. Sonographers measured each leiomyoma three separate times, recording the maximum diameter in three perpendicular planes each time. Sonographers and investigators classified type and location.
  
  
  RESULTS
  Among 458 women with one or more leiomyomas (prevalence 10.7%), we identified a total of 687 leiomyomas. The mean size of the largest leiomyoma was 2.3 cm (95% confidence interval [CI] 1.8-2.8). Mean gestational age at ultrasonography was 61+/-13 days from last menstrual period. Prevalence varied by race/ethnicity: 18% in African-American women (95% CI 13-25), 8% in white women (95% CI 7-11), and 10% in Hispanic women (95% CI 5-19). The proportion of women with leiomyomas increased with age much more steeply for African-American women than for white women.
  
  
  CONCLUSIONS
  Leiomyomas are common in pregnancy and occur more often among African-American women. Given the limited research on effects of leiomyomas on reproductive outcomes, the degree to which race/ethnic disparities in prevalence of leiomyomas may contribute to disparities in events such as miscarriage and preterm birth warrants investigation.
authors.affiliation: From the Department of Epidemiology, University of North Carolina School of Public Health, Chapel Hill, North Carolina; the National Institutes of Health, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina; Community and Preventive Medicine, Mount Sinai School of Medicine, New York, New York; the Biostatistics and Carolina Population Center, University of North Carolina School of Public Health, Chapel Hill, North Carolina; and the Department of Obstetrics and Gynecology, and the Institute for Medicine and Public Health, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: Shannon K
authors.initials: SK
authors.lastname: Laughlin
authors.forename: Donna D
authors.initials: DD
authors.lastname: Baird
authors.forename: David A
authors.initials: DA
authors.lastname: Savitz
authors.forename: Amy H
authors.initials: AH
authors.lastname: Herring
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Hartmann
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007889:Leiomyoma / Q000000981:diagnostic imaging / Q000453:epidemiology*; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000000981:diagnostic imaging / Q000453:epidemiology*; D011261:Pregnancy Trimester, First; D015995:Prevalence; D016216:Ultrasonography, Prenatal; D014594:Uterine Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology*