Risk factors for mastitis in breastfeeding women: results of a prospective cohort study.

OBJECTIVES: To identify potential risk factors for the development of mastitis in breastfeeding women. METHODS: A prospective cohort study with questionnaire and telephone follow-up was conducted. Women were recruited after delivery at either the teaching hospital or the only private hospital with an obstetric service during May to December 1994 in Newcastle, New South Wales and were followed up at home for six months. 1,075 breastfeeding women were recruited and were sent follow-up questionnaires at three, eight and 26 weeks post-delivery. RESULTS: Mastitis occurred in 20% (95% CI 18-22%) of women during the first six months. Factors that were statistically significantly and independently related to mastitis were: past history of mastitis (adjusted Hazard Ratio=1.74, 1.07-2.81), university or college education (HR=1.93, 1.18-3.16), blocked duct (HR=2.43, 1.68-3.49), cracked nipples (HR=1.44, 1.00-2.07), use of creams on nipples (HR=1.83, 1.22-2.73), particularly papaya cream (Relative Risk = 1.83, 1.36-2.47), and always starting with the alternate breast on consecutive feeds (HR=2.28, 1.50-3.44). CONCLUSIONS: Women with a past history of mastitis had an increased risk of developing mastitis. Blocked ducts and cracked nipples serve as warning signs for mastitis. Use of some creams may increase the risk of mastitis and their value should be tested in clinical trials. IMPLICATIONS: We have identified several pre-natal and post-natal markers for increased risk of mastitis that may assist in its early identification and treatment. The use of creams on nipples may introduce pathogens that cause mastitis and should be avoided.

Incidence of mastitis in breastfeeding women during the six months after delivery: a prospective cohort study.

OBJECTIVES: To estimate the incidence of mastitis in breastfeeding women during the first six months after delivery, and to identify the healthcare services used and treatments received by women with mastitis. DESIGN: A prospective cohort study with questionnaire and telephone follow-up. SETTING: A teaching hospital and the only private hospital offering obstetrics at the time of the study in the Lower Hunter Region, New South Wales. PARTICIPANTS: 1075 women in postnatal wards following delivery of a single infant who were breastfeeding at the time of recruitment. RESULTS: 233 women returned a questionnaire indicating they believed that they had developed mastitis during follow-up. Of these, 219 had mastitis by the study criteria, giving an estimated crude incidence of 20% (95% CI, 18%-22%) in the six months after delivery. Most cases of mastitis (75%) occurred within seven weeks after delivery. Multiple episodes of mastitis were reported by 63 women: 27 reported three or more episodes during six months. 160 women (73%) reported consulting a general practitioner about their mastitis. Despite National Health and Medical Research Council guidelines that antibiotics be continued for 10 days, 148 (87%) of the 170 women who were prescribed antibiotics for the first episode of mastitis took them for less than 10 days. CONCLUSIONS: A large proportion (20%) of women who were breastfeeding developed mastitis in the six months after delivery. As general practitioners are commonly consulted about mastitis, it is important that they know how to diagnose and treat this condition.