Incompetent Cervix and Pre-Term Deliveries

An incompetent cervix also called an insufficient cervix, is a serious medical condition that occurs when weak cervical tissue, the tissue at the lower part of the uterus (womb), causes or contributes to a miscarriage or premature birth. Premature birth may put the baby at risk for a number of birth injuries such as cerebral palsy, periventricular leukomalacia (PVL), seizures, developmental delays, infections, and hypoxic-ischemic encephalopathy (HIE). Cervical insufficiency can be caused by a number of factors, including congenital conditions, exposure to DES, prior obstetric trauma, prior cervical biopsy or LEEP procedure, or prior D&C procedures, among other factors.

What Is An Incompetent Cervix?

Before pregnancy, the cervix — the part of the uterus that connects to the vagina — is normally closed and rigid.  The cervix gradually softens as pregnancy progresses.  In a normal pregnancy, the cervix decreases in length (effaces) and opens (dilates) in response to contractions.  If a woman has an incompetent or weak cervix (also known as cervical insufficiency),  the cervix may shorten or open too soon, during early pregnancy. This may result in the membranes bulging through the opening and eventually rupturing, sometimes before the baby can survive outside of the uterus. The shortening or opening of the cervix may also bring on pre-term labor. If this response is not halted by medical intervention, a premature birth or miscarriage can result.

If a woman’s cervix begins to open in early pregnancy, preventative medication, frequent ultrasounds, and cervical cerclage – a procedure that closes the cervix with a strong suture, or stitch – are essential. If physicians fail to take appropriate actions to prevent premature birth, and the baby suffers a birth injury, the family may have a malpractice claim.

Incompetent Cervix - Cervical Insufficiency - Weak Cervix

Incompetent Cervix: Risk Factors

Physicians must take a thorough history of the mother in order to identify risk factors for an incompetent cervix and premature birth. Factors that may cause the cervix to open in early pregnancy include anything that can cause cervical weakness. Specifically, risk factors include the following:

  • Prior preterm delivery
  • Cervical shortening
  • History of surgical procedures involving the cervix
  • Diagnosis of cervical incompetence in a previous pregnancy.
  • Previous preterm premature rupture of membranes.
  • A biopsy of the cervix used to remove pre-cancerous cells or for diagnostic purposes (cone biopsy/cervical conization).
  • Trauma from a previous childbirth during which the cervix was torn.
  • Repeated or late-term abortion.
  • Uterine abnormalities and anomalies.
  • Exposure to the drug diethylstilbestrol (DES).
  • D & C procedures.

Short Cervix Closely Tied to Cervical Insufficiency

Short cervix (where the cervical tissue does not stay closed due to insufficient tissue length) is often synonymous with insufficient cervix and is caused by similar factors, including congenital issues, chemical exposure, and certain surgical procedures such as biopsies.

What Causes Weak Cervix?

Causes of an incompetent cervix can include:

  • Congenital conditions:  Some uterine abnormalities and genetic disorders can affect collagen (a fibrous protein that makes up the body’s connective tissues), which may cause cervical insufficiency.
  • Exposure to diethylstilbestrol (DES), a synthetic form of the hormone estrogen, before birth also has been linked to cervical insufficiency.
  • Obstetric trauma. If a woman has experienced a cervical tear during a previous labor and delivery, she could have an incompetent cervix.
  • Certain cervical procedures. Various surgical procedures — including a procedure used to take a sample of cervical tissue (cervical biopsy) and a treatment that uses an electrical current to remove diseased tissue from the cervix (loop electrosurgical excision procedure, or LEEP) — can contribute to cervical insufficiency.
  • Dilation and curettage (D&C). This procedure is used to diagnose or treat various uterine conditions — such as heavy bleeding — or to clear the uterine lining after a miscarriage or abortion. It can cause structural damage to the cervix.

Signs and Symptoms of Incompetent Cervix

If a woman has an incompetent cervix, she might not experience any signs or symptoms as the cervix begins to open during early pregnancy. Mild discomfort over the course of several days or weeks is possible, however, starting at week 15 to week 20 of pregnancy.  Women with an incompetent cervix typically have “silent” cervical dilation (i.e., with minimal uterine contractions) between 16 and 28 weeks of gestation. They present with significant cervical dilation (2 cm or more) and minimal symptoms.

When the cervix reaches 4 cm or more, active uterine contractions or rupture of membranes may occur.

Signs and symptoms of a weak or incompetent cervix include:

  • A sensation of pelvic pressure.
  • A backache.
  • Mild abdominal cramps.
  • A change in vaginal discharge.
  • Light vaginal bleeding.

Diagnosing Incompetent Cervix

If any of the risk factors for an incompetent cervix are present, the physician should review the woman’s history and perform a physical exam and ultrasound tests to determine the length of the cervix. Methods for diagnosing an incompetent cervix include the following:

  • History:  An important indicator of an incompetent cervix is if the woman has had a miscarriage between the 14th and 28th week (approximately) of a previous, otherwise uneventful pregnancy.  This is the best predictor and will alert the physician to an increased likelihood of cervical incompetence.  Other important questions for a physician to investigate are whether the woman has a history of DES exposure or congenital cervical weakness and whether she has had prior trauma to the cervix from D & C procedures or cone biopsies.
  • Physical exam: During the second or third trimester, a pelvic exam to check for incompetent cervix can reveal the partial opening of the cervix (dilation) with shortening and thinning of the vaginal part of the cervix (effacement), which would indicate a weak cervix.
  • Tests: The physician should order serial transvaginal ultrasound studies (TVS) after the 16th week in a woman with risk factors for cervical incompetence. Vaginal ultrasounds can help monitor the cervical length and determine if the cervix is opening. Ultrasound studies determine the length of the cervix; a compromised cervix may be shortened.

Treatment for Incompetent Cervix

Treatments for an incompetent cervix include the following:

  • Progesterone treatment. It is recommended that all pregnant women have their cervix measured between 19 and 24 weeks of pregnancy, and if the cervix is shortened, progesterone treatment should be considered.  When given vaginally, the hormone progesterone helps prevent preterm birth in women at risk of premature delivery due to a short cervix. Progesterone is not recommended for women pregnant with more than one baby.
  • Serial ultrasounds. If a woman has a history of early premature birth, the doctor might begin carefully monitoring the length of her cervix by having her get ultrasounds every two weeks, from week 15 through weeks 24 to 26 of pregnancy. If her cervix begins to open or is abnormally short, the doctor might then recommend cervical cerclage.
  • Cervical cerclage.  If a woman is 24 weeks or less pregnant and tests show that her cervix is opening, a surgery called cervical cerclage, that helps reinforce the cervical muscle, can help prevent premature birth.  During cerclage, the cervix is stitched shut with strong sutures, which helps the cervix remain closed under the weight of the baby.  The surgery usually entails closing the cervix through the vagina.  Another approach involves performing the cerclage through an abdominal incision. Transabdominal cerclage of the cervix makes it possible to place the stitch exactly at the level that is needed. It can be carried out when the cervix is very short, effaced or totally distorted. Cerclages are usually performed between weeks 14 and 16 of the pregnancy.  If a woman has a history of premature births that are likely due to cervical insufficiency, the physician might recommend cervical cerclage before the cervix begins to open (prophylactic cerclage). This procedure is typically done before week 14 of pregnancy.  The sutures are removed between weeks 36 and 38 to avoid problems during labor.  Cerclage is not recommended if a woman has increased irritation of the cervix, her cervix has dilated 4 centimeters, or her membranes have ruptured.

Cervical Cerclage - Preventing Premature Birth

Legal Help for Premature Birth Due to Incompetent Cervix

If your child has a birth injury due to premature birth, it is very important to choose a lawyer and firm that focus solely on birth injury cases.  Reiter & Walsh ABC Law Centers is a national birth injury law firm that has been helping children with birth injuries exclusively since 1997. Our legal team has over 100 years of joint experience in birth trauma litigation.

Reiter & Walsh, P.C. is based in Michigan, but our team handles cases all over the United States. Many of our clients have hailed from Michigan, Ohio, Texas, Wisconsin, Washington D.C., Pennsylvania, Tennessee, Arkansas, Mississippi, and other states. The Reiter & Walsh, P.C. birth trauma team has also handled FTCA (Federal Tort Claims Act) cases involving military medical malpractice and federally-funded clinics.

Contact Reiter & Walsh ABC Law Centers to begin your free case evaluation. Our award-winning birth trauma lawyers are available 24/7 to speak with you.

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Related Articles and Blogs from Reiter & Walsh ABC Law Centers


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