Early or recurrent preterm birth and maternal cardiovascular disease risk

Ann Epidemiol. 2010 Aug;20(8):604-9. doi: 10.1016/j.annepidem.2010.05.007.

Abstract

Purpose: Preterm birth (PTB) has been associated with a later increased risk of maternal cardiovascular disease (CVD). We hypothesized a more pronounced relation between early or recurrent PTB and maternal CVD risk.

Methods: We related PTB severity (earlier gestational age at delivery) and recurrence (>/=2) among women with births from 1973-1983 in Denmark (n = 427,765) to maternal CVD morbidity or mortality (1977-2006). Birth data were linked to CVD hospitalizations and deaths identified in national registers and data were analyzed using Cox proportional hazards models.

Results: Women with a prior PTB had excess CVD after adjustment for age, parity, and education (hazard ratio [HR] = 1.36 [95% confidence interval (CI): 1.31, 1.41]). This was only modestly attenuated when women with preeclampsia or small for gestational age births were excluded, and the relationship was stronger for CVD mortality (HR = 1.98 [1.73, 2.26]). Recurrent PTB was associated with higher CVD morbidity compared to women with one PTB, particularly for ischemic events (HR = 1.78 [1.40, 2.27] vs. 1.22 [1.09, 1.36]). Risk was similarly elevated among women with early, moderate, and late PTB. Sensitivity analysis suggested that confounding by smoking only partly explained these associations.

Conclusions: Women with PTB, especially recurrent PTB, were at increased risk for CVD, suggesting common causes of these conditions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Confounding Factors, Epidemiologic
  • Denmark / epidemiology
  • Female
  • Humans
  • Pregnancy
  • Pregnancy Complications, Cardiovascular / epidemiology*
  • Pregnancy Complications, Cardiovascular / etiology
  • Premature Birth* / classification
  • Premature Birth* / etiology
  • Prevalence
  • Recurrence
  • Retrospective Studies
  • Risk Assessment
  • Severity of Illness Index
  • Young Adult