Premature Cervical Changes: Why Does This Happen?

With my first pregnancy, I was on Brethine from 32 to 37 weeks. After the baby was born, it was determined that my due date was wrong, and the baby was really only 35 to 36 weeks. Now, at 25 weeks, I was told that I was slightly dilated and starting to thin out. I had this and Braxton-Hicks contractions with my first pregnancy also. This time, I have felt only a few tightenings -- nothing compared to last time. Why does this "silent labor" occur, and is there anything I can do to stop it.


Peg Plumbo CNM

Peg Plumbo has been a certified nurse-midwife (CNM) since 1976. She has assisted at over 1,000 births and currently teaches in the... Read more

What you are describing sounds like premature cervical changes, which left untreated, could lead to preterm labor. Although there are many risk factors for premature labor, about half of women experiencing this have no apparent risk factors. The best predictors are: poverty, poor nutrition, Black race and history of genital infection such as bacterial vaginosis. The fact that you have experienced one preterm birth puts you at substantial risk for another.

Although we can identify risk factors, we cannot give one reason why preterm changes in the cervix occur. Hereditary, nutritional, infectious and/or allergic causes are all suspect.

There is a new test, which I would encourage you to request. You could read more about it in one or two responses I have written to others.

Fibronectin is a substance found in the cervical/vaginal secretions before 20 to 22 weeks of pregnancy and again at the end of normal pregnancy as labor approaches. It is not normally present in secretions between 22 and 37 weeks. Fibronectin is a protein that can be described as the "glue" that attaches the fetal membranes to the underlying uterine bed.

The presence of fibronectin is a marker of disruption of the interface between the uterine bed and the fetal membranes. Its presence in cervical and vaginal secretions can predict delivery within 14 days.

The length of the cervix and its adaptation to fetal head pressure can also be determined by transvaginal ultrasound at various points in the pregnancy. We are coming to believe that the cervix is not a constant entity -- either competent or incompetent -- but operates on a continuum.

You deserve to have these tests, and I hope you are being followed by a provider who is experienced and knowledgeable.

I wish you the best with this pregnancy.

Need Advice?
Get answers from iVillage experts and other moms just like you!
Question Details
  1. Pick a subject:
Connect with 1,039,394 members just like you
Share your knowledge, ask questions.