A new study published this week has found that babies who weigh only 2.2 pounds (1 kg) or less at birth are much more likely than those with normal weight to develop chronic physical and mental problems by the age of eight.
The study which looked at 219 such children, born between 1992 and 1995, found that 14 percent had developed cerebral palsy, 21 percent had asthma, 38 percent had an IQ under the threshold denoting retardation, 47 percent had poor motor skills, 10 percent had very poor eyesight, and roughly two-thirds were characterized as having "poor adaptive functioning" and "functional limitations".
In comparison, it was found that 176 children born during the same years with normal weight, were up to three times less likely to suffer from the same problems.
The researchers say the complications developed by the low birth weight group affect a child's ability to perform basic tasks, learn and connect with others.
Study author Maureen Hack of Case Western Reserve University, says their findings highlight the extraordinary costs of care that will be needed to manage the medical, educational and other service needs, of the large portion of these extremely low-birth-weight children, who develop chronic conditions.
According to the study, medical advances since the 1990s have dramatically increased survival rates for such infants, and of the 23,000 babies born in the United States in 2002 weighing between 1.1 to 2.2 pounds (500 and 999 grams), 70 percent survived.
Jon Tyson of the University of Texas, Houston and Saroj Saigal of McMaster University in Hamilton, Ontario, Canada, in an accompanying editorial, say thorough follow-up studies of these children are needed to help address the ethical dilemmas in the care of marginally viable infants.
They say that the mortality and long-term morbidity of such infants should be related to treatment decisions to forgo or withdraw intensive care.
The findings are published in the current edition of the JAMA: The Journal of the American Medical Association.