Risk of Cervical Incompetence During Pregnancy

Content provided by the Faculty of the Harvard Medical School

Risk of Cervical Incompetence During Pregnancy

Question:

I am 19 weeks pregnant with my second child. I had a very large baby and difficult birth with my first-born. I had a severe tear and a cervical laceration that required repair. Does this increase my chance for cervical incompetence or does the repaired laceration mean my cervix will be stronger?

Answer

Cervical incompetence is the painless dilatation of the cervix that results in sudden, unexpected delivery, usually in the second trimester of pregnancy. It is different from early miscarriages, preterm labor (contractions resulting in delivery) or losing the baby as a result of trauma or heavy bleeding. While medical history alone sometimes makes this diagnosis clear, often the picture is not black and white. Cervical incompetence and the dilatation it brings can result in bleeding, rupture of membranes or contractions. Knowing what came first can be a challenge.

Women who had a previous pregnancy complicated by cervical incompetence are at higher risk for this to recur. However, it's still not clear whether other problems of cervix, such as injury during a prior delivery, put a woman at higher risk for first-time cervical incompetence.

At the time of vaginal delivery, the cervix may tear from the baby passing through or, less commonly, from instruments used to help delivery. Such tears are unusual. If a tear does occur, it can usually be quickly stitched and repaired. Whether these tears are a risk for cervical incompetence is, at least in my reading and experience, unclear. Most women with tears seem to do well in future pregnancies and are not diagnosed with subsequent cervical incompetence.

Whether you should be monitored more closely with exams or ultrasound is a matter for you and your doctor to decide. There is no good evidence that I am aware of to guide best practice here. It is also unclear what, if anything, should be done if a potential cervical problem is detected. In the past, a stitch to hold the cervix shut has sometimes been used, especially in women with a past history of incompetence. More recently, some studies suggest that using the hormone progesterone may improve outcome.

Jeffrey Ecker, M.D. is an Associate Professor of obstetrics, gynecology and reproductive biology at Harvard Medical School and a member of the Department of Obstetrics and Gynecology at Massachusetts General Hospital, where he practices maternal-fetal medicine.

Last updated:	July 20, 2009