preterm labour and short cervix
overview
during pregnancy, the cervix is a closed and sealed tunnel between the uterus and the vagina. before or during labour and delivery, the cervix stretches and flattens (effacement). at 24 weeks of pregnancy, the average cervix is about 35 mm (1.4 in.) long.footnote 1
a short cervix has a length of less than 25 mm (1 in.). women with a short cervix may have an increased risk of preterm birth. footnote 2
how is it treated?
if this is your first pregnancy or if you have never had a preterm birth, having a shortened cervix may not change the way your doctor treats your pregnancy. but if you have a very short cervix, 20 mm (0.8 in.) or less, your doctor may offer you medicine to help prevent preterm birth.footnote 2
if you have had a preterm birth, you may already be taking medicine (such as progesterone shots), so your doctor may consider other treatments for a short cervix, such as a cerclage, to prevent preterm birth.footnote 2
if you learn that you are at high risk of preterm birth, make sure that you know the symptoms of preterm labour and that you know what to do if you have them.
credits
current as of: july 10, 2023
author: healthwise staff
clinical review board
all healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
current as of: july 10, 2023
author: healthwise staff
clinical review board
all healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
cunningham fg, et al., eds. (2010). preterm birth. in williams obstetrics, 23rd ed., pp. 804–831. new york: mcgraw-hill.
american college of obstetricians and gynecologists (2012). prediction and prevention of preterm birth. acog practice bulletin no. 130. obstetrics and gynecology, 120(4): 964–973.
