Updated

A baby born weighing less than a soda can and believed to be the smallest ever to survive went home Tuesday after nearly six months in the hospital.

Rumaisa Rahman's (search) prognosis "is very good," and she is expected to have normal physical and mental development, said Dr. Jonathan Muraskas, who provided care for the tiny girl and her larger twin sister, Hiba, after their births Sept. 19 at Loyola University Medical Center (search) outside Chicago.

Rumaisa weighed 8.6 ounces at birth and measured just 9½ inches long. She is now 5 pounds, 8 ounces, and almost 17 inches long.

She still requires around-the-clock oxygen — common for premature babies with underdeveloped lungs — but will be gradually weaned from the oxygen tank, said Loyola spokesman Stephen Davidow.

Davidow said the parents, Mahajabeen Shaik and Mohammed Rahman of Hanover Park, wanted a low-key departure Tuesday for Rumaisa rather the media fanfare of when they introduced the babies to the world in December.

The other twin, Hiba, was brought home Jan. 9. Hiba weighed 1 pound, 4 ounces, and was 12 inches long at birth. She now weighs 8 pounds, 8 ounces, and is 19 inches long — about the size of a full-term newborn.

The babies were delivered by Caesarean section (search) 14 weeks early at just 26 weeks' gestation after their mother developed pre-eclampsia, involving dangerously high blood pressure.