How fFN Testing Can Help

Rapid fFN® FAQ

Fetal fibronectin testing is a safe, simple and non-invasive test that can help you and your doctor determine if your body may be preparing to give birth early. This knowledge can ensure the right care is provided for you and your baby.


The Rapid fFN® Test is a safe, simple and non-invasive test that measures whether fetal fibronectin is leaking from your uterus. Fetal fibronectin is a “glue-like” protein your body produces to help hold your baby in place. ¹ 


A positive test result could indicate that your body is preparing to give birth. A negative test result can give you reassurance that your chances are less than 1% of giving birth in the next 2 weeks. ² ³

A low fFN test result can give you great peace of mind. 99.2% of women with symptoms of preterm birth who have a fetal fibronectin test result under 50ng/ml will not deliver their baby within the next 14 days. ² ³


A small percentage of women who get the test will have a higher result, indicating that the body is “leaking” fetal fibronectin. This means that you are at higher risk of early delivery and your doctor can determine the most appropriate treatment plan.

It is important to note that not everyone with a high test result delivers early.

The Rapid fFN® Test is given by your doctor or midwife in hospital and is available in the majority of maternity hospitals (over 130) in the U.K.
The Rapid fFN® Test is typically performed as a simple vaginal swab by a doctor or midwife at a hospital. Analysis of the sample takes approximately 10 minutes.

There are no known related side effects for you or your baby.

Yes. Your doctor can decide to repeat the test as often as every 2 weeks during the period from weeks 22 to 36 of gestation.² ³

Develop a plan of action


Knowing you are at higher risk will help you and your doctor prepare for a possible preterm birth and take appropriate steps to manage your pregnancy. Depending on what week of pregnancy you are in, your doctor may suggest a number of options:⁴


Further action, including:

  • – Finding and treating any undiagnosed infection(s)
  • – Monitoring dilation and cervical changes
  • – Limiting activities
  • – Reducing stress
  • – Bed rest
  • – Consulting with a high-risk pregnancy specialist


Intervention, including:

  • – Antenatal steroid injections, which can help rapidly develop your baby’s lungs before birth
  • – Magnesium sulphate, which can offer neural protection
  • – Tocolytic drugs, which can help reduce preterm contractions


Preparing for neonatal care:

  • – Hospital admission for optimal care
  • – Transfer to an appropriate NICU hospital

Make preparations


Knowing you are at higher risk of a preterm delivery gives you and your loved ones the chance to make personal and practical preparations at home:

  • – Get enough rest, as directed by your doctor
  • – Ask for help from your support system
  • – Plan ahead for what you’ll need to keep your household running
  • – Know the signs and symptoms of preterm labor
  • – Pack a delivery bag, knowing which hospital to go to and planning transportation
  • – Make sure you have everything you’ll need when you bring your baby home


  1. Lockwood CJ, Kuczynski E. Risk stratification and pathological mechanisms in preterm delivery. Paediatr Perinat Epidemiol. 2001;15(suppl 2):78-89.

  2. Peaceman AM, Andrews WW, Thorp JM, et al. Fetal fibronectin as a predictor of preterm birth in patients with symptoms: a multicenter trial. Am J Obstet Gynecol. 1997;177:13-18

  3. Rapid fFN for the TliIQ System [package insert]. AW-04196-002, Rev. 003. Marlborough, MA: Hologic, Inc.; 2015

  4. March of Dimes. Preterm Labor and Premature Birth: Are you at Risk?  Reviewed March 2018. Accessed July 17, 2019
  5. Hologic Ltd. Data On File