*UPDATED 10/22
As an MFM specialist, I see a variety of medical conditions that affect pregnancy and delivery outcomes. One such condition is cervical insufficiency that leads to preterm birth (PTB) and pregnancy loss (PL). Today, I want to share with you more about this condition in those with a history of preterm birth.
If you have experienced PTB or PL due to cervical insufficiency and are pregnant or plan on getting pregnant, this is an important topic to understand to help support conversations between you and your healthcare provider. 15 million babies are born prematurely every year resulting in short- and long-term disability, and even death. Thankfully, we have measures that can help prevent PTB.
What is cervical insufficiency?
Sometimes the cervix isn’t strong enough to stay closed as a pregnancy grows. Formerly called an’ incompetent cervix’, this condition is now called ‘cervical insufficiency’. By definition, it is “the inability of the cervix to retain a pregnancy in the absence of the signs and symptoms of clinical contractions, or labor, or both in the 2nd trimester.” In addition, there must not be any evidence of preterm prelabor rupture of membranes (PPROM), placental abruption, or infection. Diagnosis is based on a history of painless cervical dilation in the 2nd trimester with subsequent delivery of the fetus in the 2nd trimester, typically before 24 weeks of gestation.
What can be done?
Pregnancy history suggestive of cervical insufficiency
Placement of an elective, or prophylactic, cervical cerclage is an option for those patients with a history of PTB and/or PL due to cervical insufficiency that involves temporarily sewing the cervix closed with a stitch. An elective cerclage is done at 12-14 weeks in the next pregnancy to help prevent PTB.
Your ObGyn may also recommend placing an elective cerclage if you have had one of the following:
- multiple 2nd trimester PLs or live births before 24 weeks without any evidence of labor, PPROM, infection or placental abruption
- a cerclage placed in a prior pregnancy due to painless cervical dilation in the 2nd trimester
Findings on ultrasound or physical exam that are consistent with cervical insufficiency
Sometimes a "rescue", "emergent" or "exam-indicated" cerclage is needed based on 1) painless dilation of the cervix with or without prolapsing amniotic membranes in the 2nd trimester is found on physical exam before 24 weeks in patients with or without a history of PTB or 2) an ultrasound exam shows a cervical length of less than 2.5cm at less than 24 weeks and a history of a prior birth at less than 34 weeks.
Nonsurgical options
Nonsurgical approaches to management of cervical insufficiency include activity restriction, bed rest, and pelvic rest. However, they have not been found to be effective and are not recommended. Placing a vaginal pessary may be of some benefit in certain patients.
Patients may also opt to not get the cerclage done and instead do serial cervical lengths every 1-2 weeks until 24 weeks with consideration for placement of the cerclage if the cervix starts to shorten. Some providers may also offer vaginal progesterone supplementation in addition to the serial cervical lengths.
How is a cerclage done?
I explain how a cerclage is done to help you understand what to expect in this video!
What are the different types of cerclage?
There are two types of cerclage--transvaginal cerclage and transabdominal cerclage. Both procedures are done in the hospital under anesthesia, but do not typically require an overnight stay.
- Transvaginal cerclage is done through the vagina to place a stitch in the cervix, which is then typically removed around 37 weeks of pregnancy in the office or hospital.
- Transabdominal cerclage is an open abdominal surgery (laparotomy) or laparoscopic surgery done to place a cerclage stitch higher up on the cervix from inside the abdomen. It is typically left in place until delivery through a cesarean. A transabdominal cerclage can also be left in place between pregnancies, to prevent future PTB or PL.
Possible complications with cerclage placement
As with most medical treatments, especially those related to a process as complex as pregnancy, there are possible complications with cerclage placement. These include:
- preterm prelabor rupture of membranes (PPROM)
- infection of fetal membranes and the uterus
- tears in the cervix
- the stitch moving from the correct place
- bleeding during or after the procedure
Is bed rest or cervical length measurements recommended after cerclage?
Bed rest is not recommended for those at risk of PTB or those who have had a cerclage placed. Research shows that bed rest and limiting physical activity do not prevent PTB or pregnancy loss. Bed rest can increase the risk of blood clots, bone weakening, and loss of muscle strength.
What if I am pregnant with twins and have a short cervix?
In this Instagram post, I share more specifics about cerclage in patients with twin gestations and a cervical length of <2.5cm. There are studies on this, and overall there is not an indication to recommend placing a cerclage in twin pregnancies with a short cervix. However, the evidence is sufficient to remove any recommendation against cerclage. You can go to this article by SMFM for more info.
Serial CL measurements ARE NOT recommended after cerclage placement.
Who is not a candidate for a cerclage?
If the CL is less than or equal to 25mm before or at 24 weeks of gestation and the patient does NOT have a history of a prior singleton PTB, a cerclage is not indicated.
Additional resources!
SMFM: Cervical cerclage for the woman with prior adverse pregnancy outcome
ACOG Practice Bulletin 142: Cerclage for the Management of Cervical Insufficiency
Physical Examination–Indicated Cerclage: A Systematic Review and Meta-analysis
In addition, you can read more about the latest info on routine cervical length screening and cervical cerclage from ACOG and SMFM in this post, or go to my Instagram highlight “preterm birth” for more info!
As a patient, having the knowledge and understanding about health conditions and treatment options should empower you. My hope is that the Babies After 35 blog and community empower you in your journey!