ST. LOUIS (Ivanhoe Newswire) -- It's becoming a common trend: women choosing to deliver their babies early for convenience. Traditionally, the thought was anytime after 37 weeks was OK to deliver. However, recent research may have mothers and their doctors thinking twice before choosing to deliver before 40 weeks.

It's supposed to be a time when dreams of a family come true, but when a baby is born too early, those dreams can become a nightmare.

"By 4 days old, he was 3 pounds, 14 ounces," Tami Nickerson, told Ivanhoe. "You’re just helpless. You can’t do much more than just stand back and watch."

Born four weeks early, Tami's son, Hunter, can barely be called premature, but his health problems tell another story. They include speech delays, a neurological condition called sensory integration disorder and acid reflux.

Traditionally, any delivery after 37 weeks was considered normal. However, as more and more mothers deliver before their due date, new research shows every week counts in pregnancy -- even past the 37th.

"I think we are learning more and more how important it is to avoid elective, late preterm birth," F. Sessions Cole, M.D., a neonatologist at St. Louis Children's Hospital, told Ivanhoe.

Each week a baby is born before the 39th adds a 23-percent higher chance that he'll have complications like breathing problems, jaundice and infection. A recent study found babies born between four and eight weeks early had lower reading and math scores in first grade than babies carried to term.

"Late, preterm birth is much more dangerous than we once thought," Dr. Cole said.

It's a shift in thinking that doctors hope will lead to a shift in the number of mothers choosing to deliver early.

While Tami didn't have a choice, she hopes mothers who do make the right choice.

"If you can get to 40 weeks, by all means, do it," Tami told Ivanhoe.

For now, she chooses to cherish the gift she almost lost.

"He’s the world to me. He’s my life," Tami said. "He’s everything I’ve waited for and wanted, and that’s why we worked so hard to keep him with us."

In the last decade, the number of C-sections performed in the United States has nearly doubled -- with about 30-percent of all babies being delivered by C-section.

Dr. Cole says it's important to remember that a due date is an approximation -- not an exact prediction. It's not uncommon for a due date to be off by 10 to 14 days.