Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Nov;36(4):673-686.
doi: 10.1177/0890334420907898. Epub 2020 Apr 14.

Incidence of and Risk Factors for Lactational Mastitis: A Systematic Review

Emily Wilson  1   2 , Susannah L Woodd  1 , Lenka Benova  1   3
Affiliations

Incidence of and Risk Factors for Lactational Mastitis: A Systematic Review

Emily Wilson et al. J Hum Lact. 2020 Nov.

Abstract

Background: Lactational mastitis is a maternal morbidity that affects the wellbeing of women and their babies, including through breastfeeding discontinuation.

Research aim: To systematically review the available global literature on the frequency of lactational mastitis, and to summarize the evidence on risk factors for lactational mastitis. We also describe gaps in the evidence and identify priority areas for future research.

Methods: We systematically searched and screened 6 databases and included 26 articles, conducted meta-analysis of disease frequency, and narratively synthesized evidence on risk factors.

Results: In 11 (42%) articles researchers reported a measure of disease frequency; 5 (19%) reported risk factors, and 10 (39%) included both. Overall, the quality of studies was low, related to suboptimal measurement of disease frequency, high risk of bias, reverse causality, and incomplete adjustment for confounding. Meta-analysis was based on 3 studies (pooled incidence between birth and Week 25 postpartum: 11.1 episodes per 1,000 breastfeeding weeks; 95% CI [10.2-12.0]); with high heterogeneity across contexts and highest incidence in the first four weeks postpartum. Researchers assessed 42 potential risk factors; nipple damage was the most frequently studied and strongly associated with mastitis. There was a scarcity of studies from low-resource settings.

Conclusions: Lactational mastitis is a common condition, but the wide variability in incidence across contexts suggested that a substantial portion of this burden might be preventable. Provision of care to breastfeeding women at risk for or affected by mastitis is currently constrained due to a critical lack of high quality epidemiological evidence about its incidence and risk factors.

Keywords: breast pain; breastfeeding; breastfeeding difficulties; epidemiological methods; mastitis.

PubMed Disclaimer

Conflict of interest statement

Declaration of Conflicting Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Figures

Figure 1.
Figure 1.
Search results flow chart.
Figure 2.
Figure 2.
Meta-analysis of incidence density of lactational mastitis by weeks postpartum.
See this image and copyright information in PMC

References

    1. Amir L. H., Forster D. A., Lumley J., McLachlan H. (2007). A descriptive study of mastitis in Australian breastfeeding women: Incidence and determinants. BMC Public Health, 7, Article 62. doi:10.1186/1471-2458-7-62 - DOI - PMC - PubMed
    1. Amir L. H., Garland S. M., Lumley J. (2006). A case-control study of mastitis: Nasal carriage of Staphylococcus aureus. BMC Family Practice, 7, Article 57. doi:10.1186/1471-2296-7-57 - DOI - PMC - PubMed
    1. Axelsson D., Blomberg M. (2014). Prevalence of postpartum infections: A population-based observational study. Acta Obstetricia et Gynecologica, 93(10), 1065–1068. - PubMed
    1. Baeza C. (2016). Acute, Subclinical, and Subacute Mastitis: Definitions, Etiology, and Clinical Management. Clinical Lactation, 7(1), 7–10.
    1. Crepinsek M. A., Crowe L., Michener K., Smart N. A. (2012). Interventions for preventing mastitis after childbirth. Cochrane Database of Systematic Reviews. doi: 10.1002/14651858.CD007239.pub3 - DOI - PubMed

Publication types