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Weight, Sex Affect Early Preterm Survival

For babies born extremely early, new research shows that
four factors -- aside from the baby's gestational age -- may affect their
odds of survival if given intensive care.

The four factors are:

  • Sex (survival is better for girls)

  • Single birth or multiple birth (survival is better for singletons)

  • Mother's treatment with corticosteroids before giving birth to help the baby's
    lungs develop (a plus for preemie survival)

  • Birth weight (the higher the

So says a new study of more than 4,000 extremely preterm babies born in the
U.S. at 22-25 weeks of gestation.

The study is "exciting," says Donna R. Halloran, MD, MSPH, assistant
professor of pediatrics at St. Louis University, who reviewed the study for

"I think without a doubt it will change the way we counsel
families," says Halloran, who plans to start using the findings right away
in counseling parents of extremely preterm babies.

U.S. preterm births are up 21% since 1990, according to a recent report in
Pediatrics. Most of those preemies are born at 34-36 weeks of gestation,
not at the much younger ages covered in the new study, which appears in The
New England Journal of Medicine

Extremely Preterm Babies

The researchers -- who included Jon Tyson, MD, MPH, of the University of
Texas Medical School at Houston -- tracked the babies from birth up to 22

At birth, 83% of the babies got
intensive care with mechanical ventilators to help them breathe. That
decision was up to the parents and their doctors, not the researchers, who
simply tracked the babies' progress.

Of the nearly 4,200 babies with follow-up information available 18-22 months
after birth, 61% had died or had profound impairment.

Among babies who got intensive care, survival rates were better for girls,
singletons, babies whose mothers had gotten corticosteroid treatment before
giving birth, and babies with higher birth weights.

Considering those factors, along with gestational age, may help parents and
doctors gauge the chance that intensive care will lead to a "favorable
outcome," Tyson's team writes.

Still, those patterns are "no substitute for sound medical judgment"
tailored to each baby , Rosemary Higgins, MD, of
the National Institute of Child Health and Human Development, tells WebMD.

Higgins, who worked with Tyson and other scientists on the study, says it's
not clear why survival rates were better for girls than boys. "There's
probably some biologic difference that we don't understand yet," Higgins

Better Counseling for Parents

What the study really gets at, Halloran says, is what sort of interventions
parents want for their extremely preterm child.

She reels off a list of questions those parents face, sometimes with only
hours to decide before a baby is born way before its due date .

"Should we be intervening? Should we be performing resuscitation on the
baby? Should we be putting them on a ventilator? Should we be taking what are
sometimes very extreme measures to save this baby? What's going to happen to
the baby after that?" asks Halloran, who didn't work on Tyson's study.

"It's such a difficult time" for parents, she says. "What they
want more than anything is information."

"Of course, they want to know what's going to happen to their child. But
I can't tell them that. ... We can't predict the future but we can give
them probabilities. ... Now we can be much more specific and much more
knowledgeable and confident in the counseling that we're providing."

By Miranda Hitti
Reviewed by Louise Chang
©2005-2008 WebMD, LLC. All rights reserved

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