Duration of lactation and incidence of myocardial infarction in middle to late adulthood

Presented at the 27th Annual Meeting of the Society for Maternal-Fetal Medicine, San Francisco, CA, Feb. 5-10, 2007.

Received 20 March 2008; received in revised form 21 July 2008; accepted 2 October 2008. published online 29 December 2008.

Refers to article:

Prospective evidence that lactation protects against cardiovascular disease in women
Erica P. Gunderson
American Journal of Obstetrics & Gynecology
February 2009 (Vol. 200, Issue 2, Pages 119-120)
Full Text | Full-Text PDF (66 KB)

Objective

We assessed the relation between duration of lactation and maternal incident myocardial infarction.

Study Design

This was a prospective cohort study of 89,326 parous women in the Nurses' Health Study.

Results

During 1,350,965 person-years of follow-up, 2540 cases of coronary heart disease were diagnosed. Compared with parous women who had never breastfed, women who had breastfed for a lifetime total of 2 years or longer had 37% lower risk of coronary heart disease (95% confidence interval, 23-49%; P for trend < .001), adjusting for age, parity, and stillbirth history. With additional adjustment for early-adult adiposity, parental history, and lifestyle factors, women who had breastfed for a lifetime total of 2 years or longer had a 23% lower risk of coronary heart disease (95% confidence interval, 6-38%; P for trend = .02) than women who had never breastfed.

Conclusion

In a large, prospective cohort, long duration of lactation was associated with a reduced risk of coronary heart disease.

Key words: epidemiology, lactation, myocardial infarction

a Division of Maternal-Fetal Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA

b Obstetrics and Gynecology Epidemiology Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA

c Department of Obstetrics, Gynecology, and Reproductive Biology, and Channing Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA

d Division of Preventive Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA

e Connors Center for Women's Health and Gender Biology, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA

f Department of Nutrition, Harvard School of Public Health, Boston, MA

g Department of Epidemiology, Harvard School of Public Health, Boston, MA

Reprints: Alison M. Stuebe, MD, MSc, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, School of Medicine, University of North Carolina at Chapel Hill, 3010 Old Clinic Building, CB#7516, Chapel Hill, NC 27599-7516

Cite this article as: Stuebe AM, Michels KB, Willett WC, et al. Duration of lactation and incidence of myocardial infarction in middle to late adulthood. Am J Obstet Gynecol 2009;200:138.e1-138.e8.

This study was supported in part by Public Health Service research Grants CA87969, HL34594, and HL60712 from the Department of Health and Human Services, National Institutes of Health.

PII: S0002-9378(08)02005-X

doi:10.1016/j.ajog.2008.10.001

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