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[Seawebe]

I'm 26 wks and went into preterm labor at 23 weeks. The first fetal fibronectin test my ob did was negative.
I just had a second test done today and it was positive. I did some research on the web and found that a positive result means a 1 in 5 chance of going into preterm labor.... But when? Has anyone else heard similar information? Also is it possible to get a negative result after you have tested positive?

[my3stooges]

from what I read and what the doctors say that a negative test is like 99% sure that you will not go into labor in two weeks. Then the positive test isn't not as likely that you for sure will go into labor, but the chances are that you may go into labor in the next 2 weeks, but then again you may not. What the ffn does is detects a hormone that has you go into labor.

[chukwumaonyeije]

Great question, Seawebe and great response, my3stooges Both of you are correct.  The ffn test does not tell you if you will have a preterm birth; only if you are at high risk or low risk.  A negative test means low risk.  As you said, if the test is negative there is a 99% chance that you will NOT deliver in 2 weeks.  As a maternal-fetal medicine specialists I have not seen a patient go into labor within two weeks of a negative test in the last 6 years.

A positive test does not mean that you will have a preterm delivery, but it does mean that you are at somewhat higher risk than the general population or someone with a negative test.  The risk of delivery over the same 2 week period is about 20% or 1 in 5.  However, once your doctor knows that your test is positive there are many things that they can do to reduce your risk.  Things that could be done include bedrest, limitation in activities, medications, hospitalization, steroids, etc.  You should determine which of these options are best for you with your doctor.  My experience is that taking steps after a positive test can reduce your risk to less than 20%.

Finally, since the FFn test is a "screening" test, it is normally not a good idea to repeat it.  Usually a screening test that is positive tells you that it is time to move on to another test or another treatment.  ... Think of it this way, if someone has a positive mammogram, she probably does not have cancer, but the thing to do is to go on to the next test (a biopsy) rather than to repeat the mammogram.  It's the same with FFn.  The only exception that I will mention is that sometimes an FFN will be falsely positive and misleading.  This can be caused by blood, recent intercourse or a recent vaginal exam.  If you think that your test was falsely positive due to any of those reasons then it should be repeated.  And of course if it is negative then you are back in the 99% low risk category.

Sorry about the long response, but this is one of my favorite topics.

Be well.
C. Onyeije, M.D.
Maternal-Fetal Medicine Specialist.
http://twitter.com/chukwumaonyeije

[Smily]

Thankyou chukwumaonyeije

Ive had several of these tests... after all the negative ones I remained pregnant after two weeks. Ive only had one positive one and I delivered less than 12 hours later.

[jennabee]

I had a positive test at 30 weeks, and began dilating at 34 weeks, but was induced at nearly 38 weeks due to pre-eclampsia. So, I never really went into active labor. I was having Braxton Hicks since 16 weeks, though. Never felt a painful contraction...

[mrskmac]

I had a positive at 28 weeks (30 in 2 days), but not shortening of cervix or dialation. I was not put on bed rest, just  limited activites. All it did was freak me out. I am supposed to repeat test every 2 weeks and u/s every week. If a positive means you may still not go into PTL, then I think all it does is worry you. I guess we'll see. I have 3 more days of the 2 week period and so far so good. I wonder if anyone else has had a positive FFN , but with no other signs of PTL and continued pregnancy. I am also on 17P shots, only 4 more of those left. yahoo!

[runner123]

I am not quite the situation you are looking for, because I've had signs of PTL and a short cervix.  I had positive fFNs at 24 and 29 weeks though and I'm still pregnant at 33 weeks today!   

[mrskmac]

My positive was over 2 weeks ago and no baby (30 weeks). I have been having a ton of contractions, but they are calling them braxton hicks b/c no cervical change. Seems to me the only thing you can rely on is a negative result. The internal u/s is more accurate in my book b/c you can see if there are changes to your cervix.