Newborn screening prevents disability in babies

What the research found

PKU is the clearest example. Untreated, it causes severe intellectual disability, epilepsy and behaviour problems. A 2010 Lancet review found that starting a special diet very soon after screening picks up PKU prevents most of the brain-related complications. A 2021 review found intelligence is usually within normal limits when treatment starts early and continues, though some thinking skills are slightly weaker on average.

Australian government guidance says about 1 in every 1,000 screened babies has a condition that would otherwise go undetected. It says earlier care leads to better health outcomes. Victorian guidance adds that untreated conditions can cause permanent disability, and symptoms may appear only after development has already been affected.

The benefit is not the same for every condition. For galactosaemia, a 2020 Cochrane review set out to test whether screening improves outcomes. The condition can still cause learning disabilities despite treatment. A 2019 guideline on urea cycle disorders says they can cause intellectual disability even though effective therapies exist, and delayed diagnosis is still common. A 2023 review of genomic screening says evidence of benefit still needs to be built.

What it doesn’t mean

• Screening does not prevent disability in every case. It helps only for the conditions tested, and only where an effective treatment exists. Some babies still have problems despite early treatment.
• Treatment can be hard to keep up. The PKU diet is difficult to maintain, especially for teenagers and young adults, so ongoing support matters.
• If you are contacted for a repeat test, most repeat results are normal. If you have concerns about your baby's development at any age, talk to your GP or child health nurse.