One in five women who undergo breast augmentation may be subsequently unable or unwilling to breastfeed their infants, according to research published in the Medical Journal of Australia.

Of 378 389 women who gave birth in New South Wales between January 2006 and December 2011, 892 had prior breast augmentation. Of those, 79% (705) were able to provide any breast milk to their infant at discharge from hospital, compared with 89% of women who had not had breast augmentation, the researchers from the Kolling Institute and the University of Sydney, led by Associate Professor Christine Roberts, found.

"However, among women who provide breast milk, women with breast augmentation are no more or less likely to exclusively breast milk feed their infants", they wrote.

The rate of breast augmentation is on the rise in Australia, with 8000 women undergoing the procedure in 2011. "These findings underscore the importance of identifying, supporting and encouraging all women who are vulnerable to a lower likelihood of breastfeeding", the researchers wrote.

Although the possible mechanisms involved in reduced breastfeeding after augmentation remain "unclear", a factor affecting willingness to breastfeed could be that "women with breast implants may fear transmitting silicone or other breast implant materials into breast milk". However, studies investigating women who have silicone breast implants, and their breastfed infants, have not substantiated links with adverse outcomes.

"They may also fear, or have been told by their surgeon, that breastfeeding could undo a satisfactory augmentation result.

"Another explanation is that lactiferous ducts, glandular tissue or nerves of the breast are damaged during surgery, or by pressure from the implants on breast tissue.

"Furthermore, complications of the surgery including capsular contracture, haematoma formation, infection or pain may reduce the ability or desire to breastfeed."

Roberts and colleagues concluded that their finding that one in five women are unable or unwilling to breastfeed after augmentation "should be provided as part of informed decision making to women contemplating breast augmentation surgery".