What is Cervical Insufficiency?
Also known as Incompetent Cervix or Weakened Cervix, Cervical Insufficiency (CI or IC) is a condition where a woman's cervix is unable to properly support the weight of a developing pregnancy and opens prematurely. The cervix is basically what separates the uterus from the vagina and is responsible for supporting the weight of a developing baby and preventing bacteria from entering the uterus. A normal cervix will change during a pregnancy, but will be in the 4-4.5 cm range early and gradually shorten to around 3 cm in the weeks leading up to delivery. In a woman with CI, the weight of the developing baby essentially causes a "descending" event causing the cervix to shorten from the top, and/or cause opening on the uterine side of the cervix (known as funneling) while the bottom stays closed.
A simplistic description is that a "normal" cervix is like the letter T, with the horizontal bar being the closed top of the cervix against the uterus. In someone with IC, this T can turn into a Y (the start of a funnel) and eventually into a V (a deep funnel) or a U (where the cervix is basically completely open. Here's a video on Youtube that shows an insufficient cervix where you can see some of these shapes as the cervix changes from a Y to a V to a U.
Wait, wait. Did you just say Incompetent Cervix?
Yes. That's actual the medical term for it. It's horrible. Imagine if erectile dysfunction was known as Incompetent Penis. How many black eyes would doctors be sporting if they had to walking around telling guys their penis was incompetent? It's an awful term. We prefer to say cervical insufficiency or weakened cervix.
Why is Cervical Insufficiency so hard to diagnose?
Because the cervix is not monitored regularly in non-high risk pregnancies, often times a loss before viability or a premature birth is the first hint that there could be some degree of CI. Also, there is a problematic "chicken and egg" issue because usually by the time issues present in a first pregnancy, other complications such as pPROM, infection, and contractions are often already present. Often times these are symptoms caused by CI, but they also could be the cause while the cervical change could be the symptom. By the point that other issues present, there is no way to tell whether the cervix changed first, or one of these other issues presented first and caused the cervix to change.
So then how exactly is Cervical Insufficiency diagnosed?
Cervical Insufficiency is directly diagnosed by two essential things:
1) Observance of painless cervical change via ultrasound
2) Elimination of other possible causes of cervical change including contractions, infection, rupture of membranes, and placental abruption.
If cervical change can be observed without any other known causes, a definitive diagnosis of Cervical Insufficiency/Incompetent Cervix can be given. Otherwise, it can be hard to tell what came first. Doctors also use patient history as a primary means of indirectly diagnosing CI. A patient with a history of 2nd trimester losses or premature births is very likely to have some degree of CI, since this is not a common pregnancy complication.
What problems can Cervical Insufficiency cause?
As noted in the chicken and egg issues, CI can be the cause of a variety of major pregnancy complications. When funneling develops, if the amniotic sac drops into the funnel, it can cause friction and pressure that can lead to pPROM. If the cervix is no longer providing an adequate infection barrier, it can lead to uterine and fetal infections like chorioamnionitis that may require delivery regardless of gestation to protect the mother's health. It also appears that the cervix funneling at the top plays a role in triggering preterm labor, so when the cervix begins to open it can cause contractions. All of these problems can be fatal for a developing fetus before viability, or result in a premature birth.
How is Cervical Insufficiency treated?
The primary means of treatment is a surgery called cerclage. A cerclage is a stitch that holds the cervix closed. There are a variety of techniques and approaches to cerclage. The most common techniques are called McDonald and Shirodkar. These are placed fairly low on the cervix using a vaginal approach, and have success rates upwards of 80% when placed prophylactically (around the week 12-14 mark, before the cervix typically starts changing). There are a few less common and more invasive techniques that have shown better success rates. Laurie had a transvaginal cervico-isthmic cerclage (TVCIC), which is placed very high on the cervix with a vaginal approach and has shown success rates upwards of 90%. Another variety is the transabdominal cerclage (TAC), which is placed at the very top of the cervix via abdominal surgery, and has shown success rates in the 95% territory. Most doctors are only familiar with the McDonald and Shirodkar approaches. The TVCIC and TAC approaches are only practiced by a small number of doctors and are often reserved for women who have had prior failed McDonald or Shirodkar cerclages, or have some other very clear indication as to why a "standard" cerclage would not work. The TAC can only be placed early in pregnancy up to around week 12-14, while the various transvaginal types of cerclage can be placed up to week 20-24 as a "rescue" cerclage. Rescue cerclages do have significantly lower success rates than prophylactic (preventative) cerclages, generally reported in the 40% to 65% territory. Both TAC and TVCIC cerclages can also be placed before conception as well.
Other treatments include medications (often some form of Progesterone) and possibly bedrest (depending on your doctor's personal philosophy on bedrest). Depending on when your CI is diagnosed, you may also be given regular ultrasounds from 16 to about 28 weeks to monitor for cervical change. There is also a device called a pessary that is placed at the bottom of the cervix which may be recommended in rare occasions.
I had a previous pregnancy with cervical issues. Will it happen again in my next pregnancy?
Unfortunately, CI is not something that usually goes away. It is certainly possible to have a successful pregnancy with CI, but it's basically rolling the dice. Also, since CI is a "spectrum" disorder, someone who was able to carry to term with less invasive interventions like progesterone and bedrest may not need a cerclage. Others, like Laurie, who have late miscarriages or very premature births may need a cerclage to have any chance of carrying to a live birth. This is an area where doctors have to make some very difficult judgement calls about risk factors based on your personal history.
My doctors told me that my cervix is too short or that I am risk for preterm labor due to issues with my cervix. What should I do?
Because there is so much room for judgement and so much inconclusive research related to CI, cerclage, steroids, tocolytic drugs, bedrest, and just about everything else related to the cervix, different doctors can have very different approaches to the same case. This makes it incredibly important for someone who may have CI to become a highly educated advocate for their own care! Women with CI need to learn about all the possible treatment options and fight for the standard of care that they believe they need. We would not have brought home our son Milo if we did not seek out a doctor who would try a type of cerclage that our doctors (a well respected Maternal Fetal Medicine group at an excellent hospital) were not familiar with. We also had to push for extra ultrasounds and proactive delivery of steroids. Our story may have been one with a sad ending if we did not become educated advocates. Instead, by fighting for what we felt we needed, we saved our son's life and brought him home, safe and sound.
To start, you can check out some of the links below to interact with other people who have beaten CI and brought home happy, healthy babies. Find out what they did that worked for them. Read about how they handled their situations. Get inspired by their success stories and learn from their mistakes.
What other information is out there about Cervical Insufficiency?
There is a lot of great information and support out there related to Cervical Insufficiency/Incompetent Cervix. Here are some that we found very helpful during our pregnancy journey.
Incompetent Cervix Support Forum - registration required to access most of the forums
Baby Center Cervical Incompetence Support Group
Incompetent Cervix overview article on MayoClinic.com
AbbyLoopers - registration required, lots of info/support related to the TAC and TVCIC types of cerclage