Oct. 5 (HealthDay News) -- Even though more treatments are provided for extremely preterm infants, they're no more likely to survive than they were in the mid-1990s, a U.S. study has found.

Researchers at Johns Hopkins University School of Medicine compared 75 extremely preterm infants (born at 22 to 24 weeks' gestation) delivered between 1993 and 1995 (early epoch) and 104 delivered between 2001 and 2003 (late epoch).

Mothers of infants in the late epoch group were twice as likely to be transported to a higher level of care, and they were more likely to be monitored by sonogram (48 percent), more likely to receive antibiotics (60 percent) and more likely to receive antenatal steroids (61 percent) than the early epoch group, the researchers noted.

In addition, infants in the late epoch group were more likely to receive life-sustaining interventions, such as high-frequency ventilation, chest tubes and administration of dopamine and steroids than those in the early epoch group.

But death rates for infants in both groups were the same, the researchers found.

"Mortality has not changed in our hospital over the past 10 years despite escalation in care at each gestational age studied. What has changed is the length of time until death," wrote Pamela K. Donohue and colleagues at Johns Hopkins Children's Center. "Applying all available medical technology to the perinatal care of extremely premature infants prolongs but does not prevent their death."

The study appears in the October issue of the journal Archives of Pediatrics & Adolescent Medicine.

The researchers noted an ongoing debate about "whether scientific advances can continue to lower the border of viability (the gestational age at which an infant can survive) or whether this goal should even be attempted."

Evidence suggests that extremely preterm infants are regularly resuscitated, even though many die within days after birth. This raises concerns that "aggressive resuscitation results in prolonging death and suffering in some" of these infants, the study authors said.

SOURCE: JAMA/Archives journals, news release, Oct. 5, 2009