The CDC recommends continuing to either breastfeed or give infants breastmilk when the mother is ill or infected with COVID-19. At this time research has just started regarding pregnancy and COVID-19, however early studies are suggesting that it is not transmitted in utero.
The US Centers for Disease Control recommends that mothers who have COVID-19 infection continue to breastfeed or provide expressed breastmilk. So far there is no evidence that the coronavirus is spread via breastmilk and the infant benefits from the antibodies that is transmitted via breastmilk during feeding. The mother should take precautions to prevent spreading the virus to her infant, such as wearing a mask and washing her hands before handling the infant.
Anyone who believes they may have COVID-19 (also known as novel coronavirus; 2019-nCoV; SARS-CoV-2) is encouraged to follow good hygiene practices, such as thoroughly washing their hands and wearing a protective mask to prevent spread of the virus. If someone becomes ill enough to require hospitalization, the baby should be allowed to continue breastfeeding if at all possible.
See link from La Leche League: https://www.llli.org/coronavirus/
*These recommendations are continually changing so continue to check back for updates or speak to your primary care provider/pediatrician.