What you can expect

By Mayo Clinic Staff

During the fetal fibronectin test, you'll lie on your back on an exam table. Your health care provider will place a speculum in your vagina and use a cotton swab to gently swipe secretions near the cervix. The sample will be sent to a lab for analysis. Results are typically available within less than 24 hours.

In some cases, a vaginal ultrasound is done after the sample is taken. During the ultrasound, you'll lie on your back. Your health care provider or technician will place a slender, wand-like device in your vagina to send out sound waves and gather the reflections. The reflected sound waves will be digitally converted into images on a monitor. Your health care provider or technician will use these images to measure the length of your cervix, which often decreases before labor begins. The ultrasound can also help your health care provider or technician assess your baby's size, age and position.

The ultrasound might take up to an hour. It doesn't hurt, and you can return to your usual activities immediately — although your health care provider might recommend other treatments if preterm labor is a concern.

May 10, 2013