Premature birth, or birth that happens too early (before 37 weeks of pregnancy), can lead to longer hospital stays for newborns, and can contribute to an increase in health problems over babies who are born at full term. Since it’s not always entirely clear why premature birth happens, it isn’t always something healthcare providers can work to prevent, but there are a few conditions which can make premature birth much more likely, and a few medications that can cut down on the risk if they are prescribed during pregnancy.
Three of the biggest indicators that a pregnant person may be at risk for a premature delivery are a previous premature birth, a short cervix as defined as less than 2.5cm, and a pregnancy carrying twins or multiples. If you have a short cervix, the hormone progesterone may be an important part of the line of defense.
Progesterone is not recommended if you’re having twins or multiples and are at risk for preterm birth.
Talking to your doctor about progesterone and short cervix
Screening for a short cervix may not be a routine part of prenatal care in all hospitals and regions. People who have short cervixes during pregnancy have about a 15-50% likelihood of delivering preterm. If you’re pregnant with just one baby, and your healthcare provider isn’t talking about screening for a short cervix, you can open up a discussion about the possibility before your 2nd trimester ultrasound . Many healthcare providers screen for short cervix during the fetal survey or fetal anatomy ultrasound completed between 18 to 22 weeks gestation. .
If you’re diagnosed with a short cervix, your healthcare provider may prescribe progesterone to be delivered vaginally. This may be in the form of a gel or insert. Vaginal progesterone may be prescribed to be used once daily. Women who are prescribed vaginal progesterone can begin at or before 24 weeks of pregnancy, and continue to take progesterone until 37 weeks gestation.
If you’re prescribed vaginal progesterone, it’s important to talk to your doctor if you have a history of:
- Current or recent blood clots
- Reaction to progesterone
- Breast cancer or other hormone-sensitive cancers
- Vaginal bleeding
- Liver disease
- High blood pressure, heart disease, or congestive heart failure
A short cervix can be an unexpected worry, since there’s no way to screen for it before pregnancy. Progesterone can’t prevent preterm delivery every time, but it can certainly decrease the risk.
Sources
- https://www.acog.org/clinical/clinical-guidance/practice-advisory/articles/2023/04/updated-guidance-use-of-progestogen-supplementation-for-prevention-of-recurrent-preterm-birth
- Jarde A, Lutsiv O, Beyene J, McDonald SD. Vaginal progesterone, oral progesterone, 17-OHPC, cerclage, and pessary for preventing preterm birth in at-risk singleton pregnancies: an updated systematic review and network meta-analysis. BJOG. 2019 Apr;126(5):556-567. doi: 10.1111/1471-0528.15566. Epub 2018 Dec 29. PMID: 30480871.
