Kendra and Maliyah Herrin remained in serious condition Wednesday in the intensive care unit at Primary Children's Medical Center.
Maliyah was given another unit of blood and her pain medication was switched because of a side effect, according to Laura Winder, spokeswoman for PCMC.
The girls, 4, were born conjoined. An eight-surgeon team separated them Aug. 7 and 8 in a 26-hour operation.
The girls are the daughters of Jake and Erin Herrin of North Salt Lake.