The world tiniest U.S. babies ever matured into typical kids.

Both Madeline Mann and Rumaisa Rahman shattered world records with their diminutive size at birth, each weighing less than a can of soda, "chicagotribune.com" reported. 

But years later, both Chicago suburban residents are thriving and developing quite typically away from the flurry of attention they received when they became the two tiniest babies ever born in the United States, researchers said.

A new study to be released Monday in the journal Pediatrics chronicles their development as they matured and marked milestones such as walking independently and attending college.

"These girls represent the two most extreme cases in the United States," said Dr. Jonathan Muraskas, a professor of neonatal medicine who treated both babies when they were born at Loyola University Medical Center in Maywood and kept in touch with them and their families subsequently. Muraskas was the lead author of the report.

The report marks the latest update on the girls' progress as Muraskas and other neonatologists seek to follow the lives of children born prematurely and weighing less than 1 pound, 5 ounces as they develop into adults.

Rumaisa is a 7-year-old elementary school student in the northwest suburbs who supported her own weight by 12 months and spoke single words by 22 months, according to the report.

Mann, now 22, is a senior at Augustana College, where she studies psychology. The honors student spent the summer volunteering in Ethiopia. She attended Conant High School in Hoffman Estates.

Both are small in stature. Mann is 4 feet 7 inches tall and weighs less than 70 pounds, according to the report, while Rumaisa stands 3 feet 3 inches and weighs less than 40 pounds.

Both received laser eye surgery to correct vision problems common in premature babies.

But today, both "are thriving," Muraskas said. The girls and their families declined to comment for this story.

Muraskas and his co-authors in the report contend that gestational age, far more than the birth weight, played a key role in both girls' viability.

Mann was born after 26 weeks in the womb even though her birth weight of 9.9 ounces was more akin to that of a 16- or 17-week-old.

Rumaisa was born at 25 weeks, the report shows. Her twin, Hiba, weighed 1 pound, 5 ounces at birth and measured 12 inches long. Rumaisa, meanwhile, was less than 10 inches long, about the size of a cellphone, and weighed just 9.2 ounces, a weight that remains the tiniest ever recorded worldwide, according to records kept by the University of Iowa Children's Hospital. The sisters are also the world's smallest surviving twins, according to Loyola.