Fibronectin test

At a glance

A fibronectin test checks for the presence of fetal fibronectin, which indicates that a premature labour is likely.

• Add to any scan from 23-35 weeks
• Recommended if you’re at high risk of premature labour
• No GP referral required
• Screening not routinely available on the NHS
• Tuesday and Friday morning clinics
• Convenient central London location

You will receive

• Your results in 48 hours

What happens with your results?
The fibronectin test is added to any scan within the range of 23-35 weeks or with our premature birth screening. Your results will be available 48 hours after your appointment.

What is it?

The fibronectin test is helpful if you are concerned about premature labour and premature birth, it checks for the presence of a substance called fetal fibronectin.

Fibronectin is not usually found in middle pregnancy, so when detected it is a good indicator that a premature labour is likely.

The fibronectin test is not offered on its own but it can be added to any scan within the range of 23-35 weeks of pregnancy, or it can be performed as part of our premature birth screening service. 

What is fetal fibronectin?

Fetal fibronectic is a protein produced by fetal cells that is found between the fetal sac and the uterine lining that holds them together.

It is found in the birth canal in early pregnancy and after 35 weeks when the mother’s body is preparing for labour.

It’s not usually detected in middle pregnancy, unless there’s a likelihood of early labour.

Why would I need a fibronectin test?

You may need a fibronectin test if you are:

• Experiencing symptoms of labour between 23 and 35 weeks of pregnancy
• At high risk of premature labour between 23 and 35 weeks of pregnancy
• Planning to travel in mid to late pregnancy

What happens during the test?

The fibronectin test is performed internally using a vaginal swab, similar to a smear test. There is no risk to you or the baby and the result is available in 24 hours.

The results

A positive result is inconclusive and indicates that you will go into preterm labour soon, but you may not go into labour for weeks.

A negative result is reassuring if you’re at high risk of a premature labour. It means there is a very small possibility that you will go into preterm labour within the next 7 to 10 days – giving a 99.2% likelihood of remaining undelivered.

The test can be repeated at regular intervals for women who remain at high risk.