For one of the most significant parts of many people’s lives, there are a lot of parts of the process of giving birth that don’t get discussed that often until you’re pregnant. One of these parts is the cervix, which is the barrier between the uterus and the birth canal, and which shortens and thins as the due date grows closer, so the baby can pass through. Sometimes, though, the cervix is too short too early in the process, putting both mom and baby at risk for preterm birth.
There are, however, a few things a healthcare provider may recommend to help women with short cervixes stay pregnant longer.
A cervix is considered short if it’s under 25 millimeters between 16 to 24 weeks of pregnancy. Women who are considered to be at higher risk for a short cervix, often based on a history of short cervix, prior cervical procedures, or a history of preterm birth, may be candidates to have their cervical length monitored by a series of transvaginal ultrasounds throughout the course of pregnancy starting as soon as 16 weeks.
For women diagnosed with a short cervix less than 20 millimeters, daily treatment with vaginally applied progesterone is often recommended to reduce the risk of preterm birth. Progesterone is a hormone that the body produces naturally to prepare for pregnancy and birth. The synthetic form that is often prescribed to women who have been diagnosed with short cervixes is applied every day, starting at or before week 24 and continuing on through week 37. Vaginal progesterone has not shown any benefit for women carrying multiple babies, however, or for women who are already on a different form of progesterone to reduce the risk of preterm birth. In the cases where it’s recommended, vaginal progesterone has been shown to reduce the risk of preterm birth up to 30%.
What about those with a history of preterm birth?
Some research suggested that progesterone treatment was helpful for those with a history of prior preterm birth, and that getting weekly progesterone injections would lower the risk of preterm labor. However, the PROLONG study published in 2020 found that weekly progesterone injections did not have a significant benefit for those with a history of preterm birth. Because the evidence is mixed, if you have a history of preterm birth, talk through the possible benefits and risks of progesterone treatment with your healthcare provider.
Cerclage is a procedure where a stitch is placed around the cervix to keep it from opening too early, and help women stay pregnant longer. The cerclage is only recommended for a select group of women, such as those with a prior history of cerclage in a previous pregnancy, a history of preterm birth prior to 34 weeks with a short cervix measuring less than 25 millimeters, or a second trimester loss after painless cervical dilation. Cerclage is also only right for women carrying single babies, not women carrying multiples. Women who are candidates for a cerclage given their prior pregnancy history often have this performed between 12 to 14 weeks of pregnancy. Women who are discovered to have short cervixes between 16 to 24 weeks may around 18 or 20 weeks still be candidates for cerclage placement depending on their medical history, and the circumstances associated with their short cervix. Cerclage placement can be performed in addition to vaginal progesterone if a provider deems that a woman could benefit from both treatments.
Though not a procedure or medication, your doctor can serve as your best resource throughout pregnancy when you have been diagnosed with a short cervix. Your doctor can help answer questions and give you an idea of what to look for, and what’s to come.
Interventions to manage the risks related to a short cervix are very important, as a short cervix greatly heightens the risk of premature birth. In most cases, extending pregnancy as long as possible will help to produce healthier babies.
We’re taking a look at how we present information in our articles. Please take a few minutes to complete this survey and help us improve our Ovia Pregnancy content! Tap the button below to take the survey.
- “Short Cervix in Pregnancy.” OBFocus. Focus Information Technology, 2014. Web.
- “Preventing Preterm Birth.” KeemEmCookin. Keep ‘Em Cookin’, LLC., 2015. Web.
- “Progesterone treatment to help prevent premature birth.” MarchofDimes. March of Dimes, Aug 2014. Web.
- “Cervical Insufficiency and short cervix.” MarchofDimes. March of Dimes, Aug 2015. Web.