Mother-of-two Audrey Yeo jokingly calls herself a cow because she feeds at least 15 babies with her breast milk.
"All I do all day is pump and pump, just like a cow," she said with a laugh.
She pumps about five litres of milk daily - about five times the amount for an average lactating mother.
The 28-year-old woman has been donating her breast milk for the past five months through Facebook group Human Milk 4 Human Babies-Singapore.
She even donates her milk to a five-month old girl across the Causeway whose mother works in Singapore.
Although doctors warn of the risks of infections in sharing breast milk, the parents who receive Madam Yeo's milk are grateful.
Madam Yeo, a school band instructor, bought a $600 freezer specially to store her breast milk. The freezer allows the milk to last for up to six months.
She has about 13 regular recipients. Most of them collect up to 100 packets of breast milk from her flat in Clementi monthly.
Madam Yeo has to feed her baby girl by bottle because the fast flow of milk from her breast might choke the child.
Her situation is unusual because lactating mothers produce an average of 800ml to 1,500ml per day, said lactation consultant Lim Peng Im of Department of Obstetrics & Gynaecology at National University Hospital.