What is the risk of COVID-19 lactating mother in performing breastfeeding?

They tested breast milk 6 days after birth (even in a possible vertical transmission during pregnancy) and found a negative RT-PCR test result. Anyhow, it seems important to avoid skin- to-skin contact of an infected mother with the child. Breastfeeding mostly includes that kind of contact while feeding. May be the expressing breast milk by hand or using a breast pump should be considered following all hygienic considerations in use