The Australian Medical Association is calling for better support for mothers who don't breastfeed.

Breast is still best but mothers who don't breastfeed their baby deserve greater support, says the Australian Medical Association.

The AMA has updated its position statement on breastfeeding to reflect the needs and concerns of the many mothers who don't nurse their child.

"Parents who are unable or choose not to breastfeed should be provided with appropriate care and assistance to formula feed their child," the statement reads.

An estimated 96 per cent of women start breastfeeding but the rate drops to 39 per cent by four months.

The World Health Organisation recommends exclusive breastfeeding for six months, with continued breastfeeding along with solid foods for up to two years of age.

AMA president Dr Michael Gannon says there may be many reasons why a mother doesn't breastfeed and it's "inappropriate" to make a mother feel bad for her choice.

"It's a personal decision and there might be reasons why they choose not to," he told ABC Radio.

"It's like every other bit of human anatomy and physiology, some women make enough milk for not only their own child but potentially another four babies down the street. Other women, for whatever reason, will struggle to breastfeed their baby," Dr Gannon said.

Breastfeeding is still the optimal infant feeding method, Dr Gannon says.

It provides numerous health benefits to the baby, including reduced risk of infection, asthma and sudden infant death syndrome.

Longer-term benefits of breastfeeding, stated in the AMA position statement, include lower prevalence of overweight and obesity, lower systolic blood pressure and lower levels of type 2 diabetes.

Recent research has shown that it's not just the baby who receives health benefits from breastfeeding but the mothers too.

A study led by the QIMR Berghofer Medical Research Institute in Brisbane found women who breastfed at least one child had lower risk of developing uterine cancer - the fifth most common cancer in Australian women.

Another study recently published in the Journal of the American Heart Association linked breastfeeding to a reduced risk of heart attack or stroke later in life for mothers.