Very early pre-term babies kept alive with ventilators, chest tubes and drugs to support the heart may live a little longer than they did 10 years ago, but are just as likely to die before ever going home, U.S. researchers reported on Monday.

Their study suggests the emotionally taxing and expensive care given these tiny newborns, delivered at 22 to 24 weeks gestation, does not in the end save their lives. Babies born at 22 weeks included in the study all died as infants, regardless of care.

This is a very difficult ethical dilemma for everyone involved, Pamela Donohue of Johns Hopkins Childrens Center in Baltimore, who led the study, said in a telephone interview.

Most pregnancies last about 40 weeks, and babies born earlier than 37 weeks of pregnancy are considered premature.

Donohue's team studied 160 women who gave birth at 22-24 weeks during separate two-year periods -- 1993-1995 and 2001-2003.

Those who gave birth during the current decade were more likely to receive higher-level care around the time of delivery, including sonograms, antibiotics and steroids to help with fetal lung development.

After birth, their children were more likely to be put on ventilators, drugs to boost heart and blood pressure rates and to have chest tubes inserted.

Infants born in 2001-2003 lived longer on average -- seven days, compared to two days in the 1990s.

But mortality rates did not fall, and the researchers urged greater discussion and further study both on intervention and the degree of suffering imposed on children, their families and healthcare providers.

Mortality rates ranged from 100 percent for children born at 22 weeks to 46 percent for those delivered at 24 weeks, regardless of the decade.

In fact, survival is the same as we reported for infants of similar gestational ages born 20 years ago, the researchers wrote in the journal Archives of Pediatrics & Adolescent Medicine.

Applying all available medical technology to the perinatal care of extremely premature infants prolongs but does not prevent their death.

Medicine