The Iraqi infant who underwent surgery for spinal birth defects earlier this month returned to an Atlanta hospital Wednesday so fluid could be drained from her back, officials said.

Noor al-Zahra has spina bifida, in which the backbone and spinal cord do not close before birth.

She had surgery Jan. 9 at Children's Healthcare of Atlanta to remove a fluid-filled sac from her back and to position her spinal cord in its proper place, and she was doing well enough late last week to leave the hospital. Her father and grandmother have been staying with a host family in the Atlanta area while Noor recovers.

During a checkup Tuesday, Noor's grandmother alerted doctors that swelling on the baby's back had increased.

The procedure Wednesday was expected to take about 10 minutes for doctors to place an external drain in the infant's back.

Most likely, the fluid is a harmless collection of blood and other liquid that accumulated after her spinal surgery, her surgeon, Dr. Roger Hudgins, has said. If the buildup is significant, she may need another major surgery to have a plastic tube inserted in her brain to divert fluid to her abdomen.

Doctors have been hoping to avoid the surgery because shunts require frequent medical attention, which might not be available when Noor returns to Iraq. If a shunt clogs or breaks, it can be life-threatening.

Baby Noor was discovered in December by U.S. troops during a raid. The soldiers noticed paralysis in the baby's legs and what appeared to be a tumor on her back and contacted U.S. physicians, who agreed to treat her.