CHICAGO - Doctors tend to underestimate premature babies' odds of survival and overestimate their chances of a serious handicap, and as a result, many such infants may not be getting proper care, researchers say.
The researchers surveyed about 630 obstetricians and pediatricians and published the findings in the May issue of the journal Pediatrics.
''It is very important that professionals and mothers understand that the outcomes for very low birthweight babies are far better than most people believe,'' said Dr. Michael Acarregui, an assistant professor of pediatrics at the University of Iowa who was not involved in the study.
A baby born at 37 weeks of gestation or earlier is considered premature. Normal gestation is 39 weeks. About 11.5 percent of the approximately 3.9 million babies born in the United States in 1998 were premature.
According to the researchers, the survival rate for a baby delivered at 28 weeks is 84 percent. But the obstetricians surveyed thought it was only 58 percent. And the pediatricians estimated only 68 percent.
The percentage of babies delivered at 28 weeks who are free of a major handicap, including cerebral palsy, mental retardation and developmental delay, is 89 percent. Obstetricians thought it was only 58 percent. Pediatricians estimated 54 percent.
''What this tells us is that we need to be more effective in disseminating the most accurate information,'' said Dr. Steven B. Morse, a neonatologist in private practice in Savannah, Ga., who led the study.
Obstetricians were asked what treatment they would use at 23 through 36 weeks for a woman in premature labor. Pediatricians were asked about measures such as keeping a baby warm, attempting resuscitation or using a respirator.
Among pediatricians, optimists were 1.8 times more likely than the pessimists to use respirators for infants between 23 and 27 weeks. Among obstetricians, optimists were 1.3 more times likely to perform a Caesarean section for distress in infants between 23 and 25 weeks.
''It's very important because terrible decisions can be made,'' said one researcher, Dr. James L. Haywood, a University of Alabama at Birmingham neonatologist. ''I think we're at most risk of making a poor decision when we have bad information.''
Though an increasing number of babies and their mothers are transferred to centers that specialize in premature babies, many such infants are cared for by general obstetricians and pediatricians.
The researchers sent questionnaires to about 1,850 doctors randomly selected from the directories of the American College of Obstetricians and Gynecologists and the American Academy of Pediatrics. Then pediatricians with a subspecialty practice were removed.
Morse said he believes doctors underestimate because they tend to remember their worst premature cases. Haywood suggested that doctors also may underestimate because neonatology is new and constantly changing.
The statistics on survival and handicaps are outdated, having been collected between 1978 and 1989. But the researchers argued that the prospects for premature babies have only improved since then, possibly making the under- or overestimation more pronounced.