For years, parents of extremely premature babies and the doctors who advise them have relied primarily on the baby’s estimated gestational age to determine whether the child receives intensive medical treatment to save its life or comfort care, if the child is not expected to survive.

But, a study published in a recent issue of the New England Journal of Medicine provides new insights and a new assessment tool to help parents and doctors decide on an appropriate course of treatment, based on the child’s estimated probability of survival and disability.

The criteria and a Web-based assessment tool were developed by the National Institute of Child Health (NICHD) and Human Development Neonatal Research Network, part of the National Institutes of Health, and are based on observations and data collected and analyzed from more than 4,400 infants born between the 22nd and 25th weeks of pregnancy at hospitals around the country.

The researchers note that that while these criteria are useful in helping doctors and parents understand the risks, each child is different and the tool cannot predict specific outcomes.

In a statistical analysis of those infants’ outcomes, researchers found that in addition to estimated gestational age, four key criteria influence the likelihood of a child’s survival and potential long-term disability: the infant’s sex, birth weight, whether the infant is part of a multiple birth, and whether the mother was given corticosteroids to promote infant lung development.

“I think those of us involved in this research would agree that it is one of the most important studies any of us has ever been involved with,” according to John Langer, the statistician at RTI International who, along with co-authors, developed and validated the model used to predict survival and disability.

“For the first time, parents and their doctors will have the best available information on which to base one of the most difficult and time-sensitive decisions they are ever likely to face.”

Presently, physicians and family members deciding the kind of care to provide rely heavily on an infant’s gestational age – the week of pregnancy during which a premature infant is born – which is known to greatly affect the infant’s survival. In some facilities, intensive care is likely to be routinely given to most infants born after the 25th week of pregnancy, whereas infants born before the 22nd week may be more likely to receive comfort care.

Complicating the parents’ decision, the authors note, is that gestational age is extremely difficult to estimate accurately. A preterm infant may be as much as a week or two younger, or older, than believed. These infants are born far earlier than the 38 to 40 weeks of a full-term pregnancy.

Sometimes weighing as little as 500 grams, or 1.1 pounds, these infants are the smallest, most frail category of preterm infants. Despite the most sophisticated medical care, many die soon after birth.

Some of the infants survive and reach adulthood, relatively unaffected, but others experience varying degrees of life-long disability ranging from hearing loss to blindness, to cerebral palsy, to intellectual disability.

“Many neonatal intensive care units base treatment decisions mainly on gestational age,” says Rosemary Higgins, MD, of NICHD, who co-authored the study. “We found that it’s much more accurate if the assessment is based on the combination of five factors, rather than just on gestational age.”


Source: RTI International