"I took prenatal vitamins, folic acid supplements, stopped all high-risk behavior. I even stopped dying my hair," says the 41-year-old Oklahoma City lawyer.

But six months into her seemingly normal pregnancy, Henderson went into early labor. She was hospitalized and, despite the best efforts of her doctors to stop the contractions, delivered Emma, who at 1 pound, 12 ounces, was given a 10% chance of survival.

Emma spent the next 101 days in the neonatal intensive care unit of Integris Baptist Medical Center in Oklahoma City, where she was placed on a respirator for her underdeveloped lungs. She also endured four neurosurgeries to relieve fluid buildup on her brain, and had laser surgery to repair damage to her eyes. Slowly, she improved and, weighing 5 pounds, was sent home.

Now 7 years old, Emma is a healthy and active child, despite the residual effects of her premature birth. They include a permanent shunt in her brain and a diagnosis of mild cerebral palsy.

"We are very lucky. Emma is a miracle child. You don't know to look at her that she's got cerebral palsy," says her mother.

Because she has fared so well, and because her parents are so concerned about the growing problem of premature births in the United States, Emma is serving as the March of Dimes 2003 National Ambassador.

Her role is part of a new $75 million, five-year March of Dimes campaign to increase awareness of premature births.

The campaign includes:

• Funding research to find the causes of premature birth.
• Educating families about the warning signs of premature labor and what can be done to prevent it.
• Expanding access to health-care coverage so more women can get prenatal care.
• Helping health-care providers learn ways to help reduce the risk of early delivery.

While many "preemies" grow up healthy, many others don't. Cerebral palsy, mental retardation and learning problems, chronic lung disease and vision and hearing difficulties are common problems. In fact, half of all neurological disabilities in children are related to premature birth, the March of Dimes says.

In 2001, more than 476,000 babies were born prematurely in the United States, according to the March of Dimes.

During the last 20 years, there has been a 27% jump in the number of premature births — those births that take place before 37 weeks of gestation, according to the March of Dimes. In 1981, 9.4% of births were premature, but in 2001 that percentage was 11.9%.

The March of Dimes hopes to reduce the rate to no more than 10.1% of live births within five years.

"This would mean 70,000 to 80,000 fewer pre-term babies annually," says Dr. Nancy Green, a New York City pediatrician and medical director of the March of Dimes.

Part of the increase in premature births is due to known risk factors, including a rise in the number of older women giving birth and the explosion of obesity in the United States, Green says.

Older women, for instance, are more likely to have twins, half of whom are born prematurely. "And reproductive technology has also contributed to the births of more twins and triplets," Green says. "Almost 90% of triplets are born prematurely."

But 50% of premature births, like Emma Henderson's, have no known cause — a mystery the March of Dimes hopes to solve with its new campaign, Green says.

One promising finding that coincides with the campaign are preliminary results of a recent National Institutes of Health study of 300 women who had had one premature birth. It was found that giving progesterone injections to the women beginning in the middle of subsequent pregnancies reduced the incidence of a second premature birth by 30%.

Green calls that "a significant effect."

In addition, Green says, "We are sponsoring a number of investigations looking at premature delivery and trying to identify specific biologic markers, like the effects of genetics, stress and inflammation in vaginal tracts," she says.

Apart from research into the causes of and solutions for premature births, the March of Dimes campaign seeks to better inform both women and health professionals about the prevalence and seriousness of the problem.

Surveys conducted by the March of Dimes have found that most pregnant women think the incidence of premature births has declined over time, that babies born after 32 weeks would suffer no ill effects from premature delivery, and that the women themselves weren't likely to deliver prematurely.

"Many people don't know how common and serious premature births are," Green says.

More information

Learn the warning signs of early labor by visiting the March of Dimes. A report on how progesterone might prevent premature births can be found at this ABC News site.