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How does being very small at birth affect you later in life?


Tuesday 19 November 2013 3:25pm

People born weighing less than 1500gm (very low birth weight or VLBW) tend to be shorter, have fewer friends and achieve fewer educational qualifications than their peers by the time they reach their 20s, a new Christchurch study shows.

However VLBW babies score similarly at age 20 to their peers on a range of other measures of health and social functioning - despite previous research indicating they could be impaired by their small start in life.

Brian-Darlow-UOCProfessor Brian Darlow

The research was led by Professor Brian Darlow, of the University of Otago, Christchurch. He has studied all New Zealand very low birth weight infants born in 1986 since their birth. This study involved more than 200 VLBW people now aged 22 and 23.

Result are published in the latest edition of the prestigious Pediatrics journal.

Professor Darlow says while VLBW participants do tend to be more socially isolated and achieve less academically, they were as happy with their quality of life as peers.

“This study is good news because it shows that, with some exceptions, these young people are doing pretty well despite serious hurdles early in life.”

Professor Darlow says there is clear evidence in their early years VLBW infants have increased rates of problems such as cognitive delay and emotional and behavioural issues. Data had emerged to show these problems may persist into adulthood.

However until this study there were limited population-based or longitudinal studies to prove whether this was the case.

Professor Darlow’s study showed VLBW babies were, as young adults:

  • On average 5.6kg lighter and 4.2cm shorter than their peers
  • Half as likely to have a tertiary qualification 
  • Less likely to engage in romantic partner relationships (In the past year 59% VLBW people versus 75% other had a romantic partner)
  • Almost a third more likely to have been welfare dependent

The study found no significant differences between:

  • High school completion
  • Involvement in paid employment and after tax income
  • Close family relationships
  • Quality of life and overall functioning

Professor Darlow says the next step for researchers is understanding if there are health discrepancies, such as in premature ageing, between VLBW people and their peers. His group is still looking for control volunteers, those born in NZ in 1986 after a full-term pregnancy. He is doing this work with the support of the Health Research Council and Cure Kids.

For further information contact

Kim Thomas
Senior Communications Advisor
Tel 64 27 222 6016 to arrange an interview 

Professor Brian Darlow
Tel 64 3 364 4699

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