It's all about the cervix!

Premature Birth — Every Minute of Every Day

A baby is born too soon every minute of every day in the U.S. – that’s one of every 8 babies.  Babies born before 37 completed weeks of pregnancy haven’t had enough time to fully develop their bodies or their brains. Some premature babies suffer developmental delays or lifelong disabilities such as blindness, cerebral palsy, and respiratory disease.  And, prematurity is the leading cause of infant death.

Prematurity is a difficult puzzle to solve. Thankfully, researchers are finally putting some of the pieces together.  Two critical pieces of the puzzle are the cervix, which is the lower part of the uterus, and progesterone, a naturally occurring hormone that helps prolong pregnancy.

Premature Short Cervix

The cervix is like a doorway from the uterus to the vagina.  During pregnancy, your cervix naturally shortens (effaces) and opens (dilates) as delivery nears so that your baby can enter the birth canal.  Sometimes the cervix starts to shorten too soon, as early as the second trimester.  Although this only happens to about ten percent of pregnant women, they are six times more likely to have a premature birth.

Cervical length measurements help determine if special care or treatment is necessary to help prevent an early delivery. Most women have a normal, long cervix mid-pregnancy so cervical length measurements are reassuring for them.  For the women who learn their cervix is shortening too soon, vaginal progesterone treatment is recommended to help prevent premature birth and improve the health of your baby.

Be sure to ask your doctor or midwife about cervical length and other risk factors to make sure you get preventive treatment if you and your baby need it.

A Global Challenge

  • 15 million babies are born too soon every year worldwide
  • 1 million of those babies die
  • In the U.S., there are over 500,000 premature births every year
  • The U.S. prematurity rate is among the highest in the world


Two Ways to Measure

Transvaginal Ultrasound

When people think of pregnancy and ultrasound, most think of the exam that uses a probe on the expectant mother’s stomach to see digital images of the baby.  This abdominal ultrasound exam is a great way to check the baby’s health and growth, but it is not a reliable way to view and measure the cervix.

A different type of ultrasound exam, transvaginal ultrasound, does provide a reliable cervical length measurement.  This exam uses a probe inserted into the vagina to see digital images of the cervix and uterus. The measurement is made using those images. This procedure is usually done at an extra prenatal appointment – or you may be referred to an ultrasound center or a Maternal-Fetal Medicine specialist. 

Transvaginal ultrasound is the test used to diagnose short cervix for vaginal progesterone treatment.


The CerviLenz device makes it quick and easy to measure cervical length during a regular office visit. Using a speculum to see the cervix, your prenatal care provider will insert the CerviLenz device into the vagina and measure the outside of the cervix.

The CerviLenz device can be used as the first test for short cervix to determine whether or not a transvaginal ultrasound is necessary.  This two-step approach is like testing for cervical cancer with a simple pap smear first and then only doing additional testing if that result is abnormal.

About Progesterone

Progesterone is a naturally occurring hormone that can help prolong pregnancy. If your cervix is shortening too soon, it may mean that your body is not making enough progesterone.

Research has shown that progesterone treatment can help prevent premature birth and improve the health of the baby.  Different types of progesterone are known to help pregnancies which are at high risk of an early delivery for different reasons.  For women diagnosed with a short cervix mid-pregnancy, vaginal progesterone in the form of a gel or suppository is recommended.

Learn more about the different types of progesterone in a video from the March of Dimes.


Learn More

Here are other online resources about prematurity and what you can do to find out if you’re at risk so you can get specialized care if you need it.  Most importantly, be sure to talk to your doctor or midwife about cervical length and other risk factors such as a history of premature birth and twin pregnancies.  Knowledge is power!

Woman Holding Baby

Help spread the word!

Most women don’t know that a prematurely short cervix puts their baby at risk of an early delivery.  Now that there’s a proven prevention – vaginal progesterone – women should be asking their obstetricians and midwives about cervical length measurements.  Help us educate women on this latest advance in obstetrics!

You can use the share buttons below to spread the word.  Or, just tweet or update your Facebook status with this text…

I just found out how important cervical length measurements are during pregnancy. Read this if you’re pregnant: