The overall perinatal death rate was 45 percent, ranging from 93 percent at 22 gestational weeks to 24 percent at 26 weeks, the study found. Among live births, 22 percent of the infants died within six days of delivery, including 8.2 percent who died in the delivery room and 5 percent died from seven to 27 days after birth.
Altogether, 30 percent of the infants who were born alive died before the age of 1 year. The number of stillbirths, delivery room deaths, neonatal deaths and infant deaths decreased with gestational age. For infants surviving 28 days, there was no significant association between gestational age at birth and one-year survival, Marsal's team found.
Treatment with tocolytics, which are drugs that delay or stop labor, corticosteroids or both appeared to help lower the odds of death. So did treatment soon after birth with surfactant -- a fluid produced shortly before birth that prevents the lungs from filling with water. Birth at an "advanced care" hospital was also associated with a lower risk of infants dying, the Swedish team found.
"We believe that the good Swedish results are due to the excellent collaboration between obstetricians and neonatologists, a high degree of centralization of very preterm deliveries to tertiary level perinatal centers, and proactive perinatal management," Marsal said.
Dr. F. Sessions Cole, director of newborn medicine and head of the neonatal intensive care unit at St. Louis Children's Hospital, believes that more needs to be done to prevent premature delivery in the first place, however.
"Gestational age at the time of delivery continues to be an important predictor of a live birth, survival until discharge from the neonatal intensive care unit, and survival until one year of age," he said.
Because the study was executed as an observational study, it did not look into ways to prevent preterm birth or improve neonatal outcomes, Cole said.
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