title: Inter-pregnancy interval and adverse outcomes: Evidence for an additional risk in health disparate populations.
abstract: OBJECTIVE
  Short interpregnancy interval (IPI), <18 months between pregnancies, is a potential cause of adverse delivery and birth outcomes, and may be a particular issue among those with other risks. Our goal was to examine IPI and delivery/infant complications in Tennessee.
  
  
  METHODS
  Birth certificate/vital records data included 101,912 women with a previous delivery. IPI groups (<6, 6-12, 12-18, 18-60 months) were compared on outcomes.
  
  
  RESULTS
  Thirty-nine percent of the deliveries had IPI <18 months, 9% were <6 months, rates 11% and 27% higher than nationally. Women with IPI <18 months were younger, lower educated with lower income, had higher BMIs, and were more likely to be unmarried, smokers, and have begun prenatal care later (p < .001). In adjusted analyses, IPI <18 months predicted elevated risk for precipitous labor, low-birth weight, preterm delivery, NICU admission, and infant mortality, with effects strongest for IPI <6 months. Finally, risks related to IPI <6 months were substantially higher for the lowest income women.
  
  
  CONCLUSIONS
  Rates of less than optimal IPI were high in this population already experiencing significant maternal-child health disparities, with short IPI a particular risk factor for poor outcomes for the most disadvantaged women, suggesting yet another precursor for adverse birth outcomes in those already most at risk.
authors.affiliation: a Department of Family Medicine, Division of Research , East Tennessee State University , Johnson City , TN , USA.
authors.forename: Shyama
authors.initials: S
authors.lastname: Appareddy
authors.affiliation: b Department of Pediatrics, Division of Neonatology , Vanderbilt University , Nashville , TN , USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Pryor
authors.affiliation: a Department of Family Medicine, Division of Research , East Tennessee State University , Johnson City , TN , USA.
authors.forename: Beth
authors.initials: B
authors.lastname: Bailey
mesh_terms: D000328:Adult; D001721:Birth Intervals / Q000706:statistics & numerical data*; D005260:Female; D054625:Healthcare Disparities; D006801:Humans; D011247:Pregnancy; D013714:Tennessee
keywords: Inter-pregnancy interval; adverse pregnancy outcomes; maternal-child health disparities