If you have cervical insufficiency, it means that your cervix is effacing and dilating prematurely (before your baby is full term). This might happen in the second or early third trimester if your cervix is softer and weaker than normal or is abnormally short to begin with, as the weight of your growing baby puts increasing pressure on it. There are usually no contractions or other symptoms.
Cervical insufficiency (sometimes called “incompetent cervix”) can result in second-trimester miscarriage; preterm premature rupture of the membranes (PPROM), in which your water breaks before you’re full-term and before you’re in labor; or preterm delivery (before 37 weeks). It particularly increases your risk for early preterm delivery, which means giving birth before 32 weeks.
In the past, you would have been diagnosed with cervical insufficiency after you had had several second-trimester miscarriages or early preterm births with no other known cause. There is still no good way to screen for cervical insufficiency, but if you’re at risk for this condition, your practitioner may order regular transvaginal ultrasounds beginning at 16 to 20 weeks to measure the length of your cervix and to check for signs of early effacement (shortening).
If your practitioner finds significant changes, you’re at a much higher risk for preterm birth. And the shorter your cervix, the greater the risk. But diagnosing this condition is still tricky, and there’s a lot of controversy about whether any treatment strategies will help prevent a late miscarriage or preterm delivery.
If an ultrasound shows you have an abnormally short cervix, you’re less than 24 weeks pregnant, and you have other risk factors for cervical insufficiency, your practitioner may recommend a cerclage. This is a procedure in which a band of strong thread is stitched around your cervix to reinforce it and help hold it closed. Your practitioner will continue to check your cervix regularly for signs of changes until the stitches come out, usually at 37 weeks. Once you reach that point, you can relax and wait for labor to begin.