Screening tests are not perfect. Sometimes 'false positive' and 'false negative' results can happen.
False positives
A positive result is a result showing you or your baby are at risk of having a health problem.
A false positive is when a test suggests you or your baby have a health problem, but further testing later shows you do not.
False positives can be very worrying for pregnant women, partners, support persons and families. They can also mean you or your baby end up having extra tests done.
False negatives
A negative result is when the test shows that you and your baby are not at risk of having a health problem.
Sometimes screening tests do not identify an actual health problem. This is called a 'false negative'.