Public Release: 

Preemies defy odds and overcome difficulties by adulthood: Study

McMaster University

Hamilton, ON (February 7) - Look around, can you tell who among your friends were tiny, preemie babies?

As young adults, the majority of extremely low birth-weight infants are attaining similar levels of education, employment and independence as normal birth-weight infants, according to a study by researchers at the Michael G. DeGroote School of Medicine at McMaster University in the February 8 issue of the Journal of the American Medical Association (JAMA).

This is good news for the infants and their parents, as more than a quarter of low birth weight children have development difficulties such as cerebral palsy, blindness and delayed development, compared to two per cent of normal birth-weight infants.

Dr. Saroj Saigal, professor of pediatrics, conducted a study over two years to determine the outcomes at young adulthood of extremely low birth-weight infants, in comparison to a group of normal birth-weight children.

The measures of successful transition to adulthood included educational attainment, student and/or working roles, independent living, getting married, and parenthood.

The study included 166 extremely low birth-weight people who weighed 1.1 to 2.2 lbs. at birth and were born between 1977 and 1982 as well as 145 socio-demographically comparable normal birth-weight participants.

The low birth-weight infants have been followed from birth, the normal birth-weight children were recruited at age eight years. Both the low birth-weight and normal birth-weight children were assessed at ages eight, as teens and at young adulthood of 22 to 25 years old.

The proportion of participants who graduated from high school was similar (82 percent of low birth weight infants compared to 87 percent of those with normal birth weight). Overall, no statistically significant differences were observed in the education achieved to date. A substantial proportion of both groups were still pursuing postsecondary education (32 percent versus 33 percent).

No significant differences were observed in employment or school status, as 48 percent of low birth-weight and 57 percent of normal birth-weight young adults were permanently employed.

No significant differences were found in the proportion living independently, married/cohabiting, or who were parents.

The age of attainment of the above markers was similar for both groups. These findings hold even though participants included the 27 per cent of low birth-weight and two per cent of normal birth-weight people with disabilities.

"Against our expectations and many odds, a significant majority of young adults who were low birth weight infants have overcome earlier difficulties to become functional members of society," said Dr. Saigal, a neonatologist with the McMaster Children's Hospital in Hamilton.

"It isn't clear what factors contributed to the positive outcome beyond adolescence, as all through childhood the low birth weight cohort was significantly compromised in comparison with their peers. Our study should provide hope to parents for an equivalent, if not a better, future for their premature children in the longer term."

Saigal says more studies from research centres with established databases from the recent era are needed.


The study was supported by grants from the Canadian Institutes of Health Research and the U.S. National Institute of Child Health and Development.

Note to editors: Television inquiries - Interviews can be arranged using a live feed from the campus. Call to schedule airtime.

Interviews can also be arranged with NBW and ELBW adults who participated in the study.

Dr. Saroj Saigal
Professor, Department of Pediatrics
Michael G. DeGroote School of Medicine
McMaster University
(905) 521-2100, ext. 76959

Veronica McGuire
Coordinator, Media and Community Relations
Faculty of Health Sciences
McMaster University
(905)525-9140, ext. 22169

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