MB3 171b: Post Childbirth and Newborn Care on Shabbos (330:6-7)

Turning on the heat on Shabbos for a woman within 30 days of giving birth. For the first seven days, the mother has the status of a חולה שיש בה סכנה. From day eight to day thirty she has the status of a חולה שאין בה סכנה.

Anything can be done to save the life of a newborn.

Cutting the umbilical cord and dealing with the placenta on Shabbos.