Preterm Birth and Adult Illness

By Rita Beamish

Premature birth is a global killer.

Leaving the womb too early accounts for more than 1 million infant deaths each year, the latest data reveals, almost half of all newborn mortality worldwide. But it’s not just the toll on newborns that increasingly concerns health experts. Paralleling the rise in early births are advances in medicine that allow more preterm babies to survive. Scientists are finding  the complexities of perinatal health and prematurity have implications for physical and neurological problems that shadow the survivors into adulthood.

Researchers at Stanford and elsewhere are working to stem early labor while trying to understand and reduce the longer term health effects of being born too early.

“Much larger numbers of people who were born preterm are now surviving to adulthood. Their health outcomes in adulthood will have an increasing public health impact over the next few decades,” said Dr. Casey Crump, clinical assistant professor of medicine at Stanford University, leading researcher on prematurity, and a Stanford Center on Longevity Faculty Affiliate.

For starters, he cited “extensive and growing evidence for an increased risk of morbidities throughout the life course.” And at least one study showed elevated risk of dying in young adulthood – although Crump noted the absolute risk for death was low, meaning that most preterm babies have life spans similar to their full-term peers.

The United States holds the dubious distinction of having the highest rate of preterm births – those born before 37 weeks of gestation – of any developed nation, up 36 percent in three decades.

More than 12 percent of U.S. babies are born preterm, or more than half a million a year. The startling reality finds the United States in the ranks of Thailand, Turkey and Somalia, according to recent data compiled by the World Health Organization and the March of Dimes. Richer countries on average log 9 percent prematurity.

Poor countries suffer significantly from influences like infections, malaria, HIV and teen pregnancy, while U.S contributing factors include both older women and teenagers giving birth,  fertility-treatment-driven multiple births, and risk factors like maternal obesity, hypertension, diabetes, smoking . The U.S. pricetag in health care spending and lost productivity is as much as $26 billion a year, the Institute of Medicine reports.

Researchers at Stanford’s March of Dimes Prematurity Research Center are trying to puzzle out the pathways and causes of early labor. Using multidisciplinary research, they hope to shed light on the little understood interplay among environmental and social influences, internal microorganisms and risk factors, and find ways to prevent preterm births, said Center on Longevity Affiliate Dr. Paul Wise, Stanford professor of pediatrics and co-principle investigator at the prematurity center.

 Premature birth, said Wise, is “a potentially important illustration of how early life events and preventing these adverse events could have long term implications for adults and public health.”

Researchers have found that children born more than three weeks early are at risk for cerebral palsy, developmental delays, hearing and vision impairment.