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Incompetent Cervix

The cervix connects the uterus to the vagina, and is about two inches long. It keeps the uterus closed and should be very firm. At the end of pregnancy, contractions and other changes cause the cervix to soften and dilate so the baby can be delivered.

An incompetent cervix dilates without contractions, usually in mid-pregnancy (18-22 weeks). It is usually diagnosed after a woman has lost a pregnancy between 18 and 24 weeks without going into labor. Sometimes incompetent cervix is diagnosed based on the results of an ultrasound.

  • Symptoms include a feeling of pelvic heaviness or lots of discharge. An examination may find that your cervix is dilated and the amniotic membrane has started to come out.
  • Causes include previous childbirth, surgery such as LEEP or cone biopsy, and late pregnancy termination. Often, a cause cannot be determined.

Treating incompetent cervix

To prevent miscarriage, your doctor may prescribe strict bedrest or a procedure called cervical cerclage, where a stitch is placed high up around the cervix to keep it closed, usually between 13 and 15 weeks. Or you may need both bedrest and cerclage, depending on the severity of your condition.

  • The stitch is usually placed through the vagina and is usually removed around 37 weeks. Surprisingly, labor may not start for weeks.
  • Occasionally, when the cervix is very damaged and previous attempts at cerclage through the vagina have not been successful, the stitch is placed through an abdominal incision. This procedure requires a cesarean section to delivery the baby. The stitch is usually left in place for future pregnancies.

Complications of cerclage

  • The amniotic membranes may rupture when the cerclage is placed.
  • The uterus may become irritated, starting labor.
  • The placenta or uterus may become infected.
  • The cervix may be damaged if contractions tear the cerclage out.
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