Incompetent Cervix: Causes, Risk Factors, Symptoms & Treatment


Pregnancy complications can hit any part of your body any time during your pregnancy. Some pregnancy complications are undetectable and harder to diagnose than others, and are quite life-threatening for the baby. Incompetent cervix is one such complication of pregnancy that is usually discovered when it is too late.

Incompetent cervix is one of the more dangerous pregnancy complications for your baby as it usually ends up in pre-term labor or miscarriage, the former brining with it a host of health problems and the latter causing the death of the foetus. Regrettably, there is nothing you can do if you have an incompetent cervix except pray for the best and cross your fingers.

Incompetent Cervix pregnancy complicationAlso known as cervical insufficiency, incompetent cervix affects about 1 in 100 women. Most people are not even aware that such a pregnancy complication exist and a majority of women will go their whole lives without ever hearing about the condition, let alone experiencing it. That being said, it is always in your best interests when you are pregnant to learn as much as possible about what a normal pregnancy should be like as well as the worst case scenarios with the pregnancy complications. This kind of self-education makes it slightly easier to manage the situation if you do encounter a problem in your pregnancy.

What is an Incompetent Cervix?

Before we get into what an incompetent cervix means, let’s take a look at the normal development of the cervix during pregnancy.

The cervix is located directly above the vaginal canal and right below the uterus. During pregnancy, the cervix goes through a wondrous transformation. The cervix is designed to protect the baby in the uterus from the outside world. So when you get pregnant, the cervix will develop a mucous plug; as the name suggests this mucous plug literally acts as a stopper, preventing anything from the outside the uterus getting in and vice versa. The cervix and the mucous plug are very strong and can easily withstand the weight of the growing uterus and the organs. The mucous plug will drop off a few days or weeks before you are about to give birth. You will probably see a pinkish mucousy discharge on your underwear when this happens.

When you go into labor, the contractions of the uterus encourage the cervix to dilate bit by bit in anticipation of the birth of the baby. The cervix is capable of dilating up to 10 cm. Considering that the opening of the cervix is even smaller than the size of the head of a ear bud, that’s a lot of dilating. And once you have delivered your baby, the cervix will begin contracting to its original size, which can take thirty minutes to an hour.

The cervix is made mostly of collagen – a sturdy substance that is nevertheless flexible when it needs to be. The cervix can stretch and thin out to an extreme to accommodate the size of a baby’s head.

An incompetent cervix signifies a problem with the firmness of the cervix. When a woman has an incompetent cervix, it does not remain closed throughout the pregnancy but opens up when the pressure of the uterus gets too great for it. The cervix will dilate – painlessly, and the amniotic sac will fall into the opening to some degree. If this occurs in the earlier stages of pregnancy, the whole sac can slip out of the uterus altogether. If the cervix is unable to remain closed for the full duration of the pregnancy, it is known as incompetent cervix.

Cervical insufficiency or incompetent cervix usually occurs before the baby can safely make it in the outside world – this means any time before 32 weeks. This condition can lead to very dire complications. An incompetent cervix can start to give way in the middle of the pregnancy second semester or, in some cases, at the start of the pregnancy third trimester.

Pregnancy Complications of Incompetent Cervix

Miscarriage: The most common pregnancy complication of an incompetent cervix is miscarriage. Miscarriage is the involuntary termination of a pregnancy, when the body terminates the pregnancy for whatever reason. It is theorized that as much as 25% of miscarriages in the pregnancy second trimester are a direct result of incompetent cervix.

Pre-term labor: This is a pretty obvious pregnancy complication of an incompetent cervix. Since the cervix is not strong enough to sustain the growing weight of the uterus, it will signal the body to bring on labor prematurely so it can expel the cause of the pressure. Babies born prematurely due to an incompetent cervix have as much of a chance surviving as premature birth caused by other pregnancy complications, depending on how far along you are when you go into pre-term labor, and whether or not your pregnancy was progressing smoothly. The earlier you go into pre-term labor, the lower the chances of your baby surviving.

Pre-term labor has its own complications since the baby has not had sufficient time in the womb to grow and fully develop. There could be deafness, blindness, low birth weight, behavioral issues, breathing difficulties, infection, and even death.

Causes of Incompetent Cervix

The reasons for an incompetent cervix are unknown. Some doctors feel that it may have to do with a structural weakness of the cervix itself – meaning that a woman is just born with a weak or too soft cervix. Other theories state that perhaps the was cervical damage in a prior pregnancy which caused the weakness to occur, or that the pregnancy hormones had something to do with it. But the fact remains that this condition is not properly understood and plenty of research needs to be done into incompetent cervix to identify the actual causes.

Risk Factors of Incompetent Cervix

There are certain common elements in some cases of incompetent cervix. They are treated as risk factors for cervical insufficiency. This means that if you have experienced any of the following, you may be at a slighter higher risk of incompetent cervix than those women who haven’t.

  • If one or more of your prior pregnancies ended in miscarriage during the second trimester or later, it is very likely that you have an incompetent cervix.
  • Any kind of surgery on the uterus seems to cause an incompetent cervix.
  • Shorter than usual cervical length is a pretty high risk factor for incompetent cervix.
  • If you have had a cone biopsy – a procedure used to detect cancer of the cervix – it may raise your chances of an incompetent cervix.
  • Exposure to DES (diethylstilbestrol) has been known to cause anatomical anomalies. It is speculated that a malformed or weak cervix may be a result of the exposure. 
  • Dilation and cutterage (D&C) in a prior miscarriage or abortion increases your risk for incompetent cervix as it may cause some damage to the cervix.

Symptoms of Incompetent Cervix

There are no accepted symptoms of incompetent cervix. But many women who have suffered from the condition have reported the following symptoms somewhere around and after the fourth month of pregnancy.

  • Some women have felt the weight of the uterus drop lower in the abdomen. This may be because the cervix has dilated to quite an extent and the amniotic sac has dropped into the opening of the cervix.
  • A feeling of wanting to go to the toilet with no result or a heaviness in the pelvis may be an indication that you have an incompetent cervix.
  • Vaginal bleeding may be caused by an incompetent cervix. However, vaginal bleeding during pregnancy is a symptom of several other pregnancy complications so do not jump to conclusions.
  • You pass your mucous plug – this will be a mucousy discharge that is not like any other discharge you have seen during your pregnancy, tinged with pink.
  • In a few cases, the amniotic sac may descend far too low and almost through the cervix and break. This can cause a gush of discharge.

Diagnosis and Treatment of Incompetent Cervix

Unfortunately, the lack of symptoms does not allow for prior detection of an incompetent cervix. Since this is not one of the more common pregnancy complications, your doctor will not even check you for it. Many women who typically have the risk factors of incompetent cervix do not end up with the condition. So identifying and diagnosing an incompetent cervix is not easy.

If you have had one or two miscarriages in your previous pregnancies, you may be checked for an incompetent cervix only then. A sad fact, but there is no helping it at this point as medical technology has just not come to the level where a scan or test can highlight the problem beforehand. But once you are diagnosed with an incompetent cervix, your doctor will know to take special care of you right from the start of your next pregnancy and to take measures so that a miscarriage or pre-term labor does not occur. An ultrasonography can sometimes expose an incompetent cervix.

The most common and widely accepted treatment for an incompetent cervix is a cervical cerclage. This simply means that the opening to your cervix will be stitched together to hold it in place. You will be advised to abstain from sexual intercourse and to stay in bed as much as possible to prevent the stitches from coming apart. The procedure will be done somewhere in the start of your pregnancy second trimester at your doctor’s discretion. But don’t worry, the stitches will be removed when you enter your 32nd or 34tth week of pregnancy so that they do not interfere with contractions and labor. By this time, your baby will be able to survive if it is born prematurely. Depending on how severe your case of incompetent cervix is, your doctor may advise inducing labor before your complete your term so as to avoid any nasty surprises.

Some doctors are not so comfortable suggesting a cervical cerclage as it has been known to cause several other complications in some women, and miscarriage in rare cases. Speak to your doctor about the procedure in detail and weigh the pros and cons together before deciding what to do.

Prevention of Incompetent Cervix

There is nothing you can do to prevent cervical insufficiency or an incompetent cervix. Since the reasons are largely unknown, it is near impossible to come up with ways to prevent the complication from occurring. There is no way to detect an incompetent cervix until you are pregnant and the problem shows up. So you cannot even take preventive measures the first time around. However, if you know from a prior miscarriage or pregnancy that you have an incompetent cervix, your doctor will monitor you closely from the very start of your pregnancy, and somewhere around the end of your pregnancy first trimester or the beginning of your pregnancy second semester, you can get a cerclage to prevent the complications of incompetent cervix from showing up.


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