Hanover, NH -- Despite unrivaled resources devoted to neonatal intensive care in the US, tiny newborns have similar survival to those in other developed countries, Dartmouth Medical School researchers found, contradicting a common assumption that at-risk infants in the US fare better.
Analyzing reproductive, prenatal and postnatal care in the US, Australia, Canada and the United Kingdom, Dartmouth Medical School pediatricians Lindsay Thompson, David Goodman, and George Little found little difference in national survival rates for low birth weight babies at one month or one year of age.
Their study, published in the June issue of Pediatrics, adds to the concerns reported last month in the New England Journal of Medicine by another Dartmouth team that more neonatal intensive care resources are not necessarily better, and offers insights into how health care resources affect mortality or survival.
Drawing on information from 1993-2000, the DMS researchers documented that the US spent far more on neonatal intensive care, but placed less emphasis on reproductive and prenatal care, compared with Australia, Canada and the United Kingdom. And although the US has a higher overall incidence of low birth weight, its resources still surpass those of the other countries, even taking the sicker babies into account. For example, the US has 40 percent more neonatologists for high-risk infants than the next best-staffed country.
The authors question the effectiveness of the current distribution of reproductive resources in the US health care system and the marginal benefits of additional neonatal intensive care.
They urge taking some cues from the other three countries that place more weight on preconception and prenatal care and suggest the US improve funding and access for reproductive care, while retaining the status quo for neonatal services.
"This study refutes a common assumption that even though the US has a poor international rank for infant mortality, it has the best birth weight-specific mortality rates," notes lead author Thompson. "Given the high levels of postnatal resources in the US, finding no better outcomes for infants was discouraging," she says.
"We stratified the babies by birth weight to 'level the playing field' for comparison. The smallest babies do worse in any country. Before, it was assumed that a two-pound baby does better in the US, but we found that a two-pound baby has about an equal chance in any of these countries."
The researchers looked at newborn death rates per 1000 live births, by birth weight categories from 500 grams to the normal weight of 2500 grams (5.5 pounds). There was no consistent pattern of better outcome in any category.
Surprisingly, however, the US had a significantly higher infant mortality rate for normal weight infants (2.6 per 1000 live births). Just reducing this rate to that of Canada, with 2.3 per 1000 births, would prevent almost 3000 deaths, the researchers say. (Most additional deaths were from Sudden Infant Death Syndrome, which was not the main focus of the study.)
US families could benefit from improved health care services before birth, says Thompson. "If you think of a newborn as the combined success of a mom's health, her pregnancy, the delivery and then the baby itself, it appears that the other countries offer more services prior to delivery.
We should think about the spectrum of care, from a teenager not desiring pregnancy all the way to a pregnant mother and the birth of a child, and, if needed, highly specialized care once a child is born."
The way other countries systematically approach reproductive health care affects their babies' outcomes, Thompson continues. "They have really good reproductive care and lower rates of low birth weight; we have really good neonatal care and higher rates of low birth weight, and yet our low birth weight babies do no better in comparison. The question is: as the US health care system grows, how do we direct more perinatal resources?"
While the US does not appear to need more neonatal specialists, intensive care beds or nurseries, simply reducing the number of neonatologists would be a mistake with unintended consequences, she warns. Instead, for example, "we could add resources towards the improvement of care within neonatal intensive care units or towards the reduction of unintended pregnancies and provision of more effective prenatal care."
Previous studies have shown that pure dollars don't always lead to better outcomes. It's unclear why the other countries are able to get more for their health care money, but there are marked differences beyond the four countries' funding levels. The availability of health insurance and the organization of physicians, clinics and hospitals influence health. And, Thompson speculates, elements beyond health care, such as the social system and society structure, may also have an influence.
Though no country has consistently better survival, there are likely virtues in the reproductive health care systems of each country that could provide clues to help improve the odds for all newborns.
The study was funded by the Agency for Healthcare Research and Quality and the Robert Wood Johnson Foundation. For more information, please contact Lindsay Thompson, MD, MS, at Lindsay.A.Thompson@Dartmouth.edu.
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