Obstetric Cholestasis

Understanding the liver, bile and and bile ducts

The liver is in the upper right part of the abdomen. The functions of the liver include: storing glycogen (fuel for the body) which is made from sugars; helping to process fats and proteins from digested food; making proteins that are essential for blood to clot (clotting factors); processing many medicines which you may take; helping to remove poisons and toxins from the body.

What is obstetric cholestasis?

Obstetric cholestasis is a condition of the liver which occurs in some pregnant women. Cholestasis means there is a reduced flow of bile down the bile ducts in the liver. Some bile then 'leaks' out into the bloodstream, in particular the bile salts. These circulate in the bloodstream and can cause symptoms. Obstetric cholestasis is sometimes called intrahepatic cholestasis of pregnancy.

Who gets obstetric cholestasis?

Obstetric cholestasis occurs in about 1 in 100 pregnancies in the UK. It is more common in women carrying twins, triplets, or more. Mothers, daughters and sisters of affected women have a higher than average risk of also being affected when pregnant. It is more common in certain parts of the world. For example, in some countries in South America, especially Chile and Bolivia, up to 1 in 20 or more pregnant women develop this condition. (These facts support the theory that there is a strong genetic factor involved - see below.) If you have obstetric cholestasis in one pregnancy, you have a high chance that it will occur in future pregnancies.

What causes obstetric cholestasis?

The exact cause is not clear. Hormonal and genetic factors may be responsible.

• Hormone factors. Pregnancy causes an increase in oestrogen and progestogen hormones. These can affect the liver in a way which slows down the rate of bile passing out along the tiny bile ducts. Some pregnant women may be more sensitive to these hormone effects.
• Genetic factors. Obstetric cholestasis seems to run in some families (although it may skip some generations). One theory is that women who develop obstetric cholestasis may inherit a slight problem with the way bile is made and passes down the bile ducts. This does not matter when not pregnant. However, the high level of hormones made during pregnancy may 'tip the balance' to cause a much reduced flow of bile.

There may be other environmental factors which contribute. However, whatever the underlying cause, the pregnancy 'triggers' the problem. Within a week or so after giving birth the symptoms clear and there is no long term problem with the liver.

What are the symptoms of obstetric cholestasis?

Typically, symptoms occur in the last third of pregnancy when the hormone levels are at their highest. However, it sometimes develops earlier in pregnancy.

Itch

This is the most common and typical symptom. The itch can be 'all over', but it is often worst on the hands and feet. Commonly, itch is the only symptom. It tends to get worse until you have the baby. The itch can become severe and affect sleep, concentration, mood, and can become distressing.

Note: mild itching from time to time is normal in pregnancy. However, if you develop a constant itch that gets worse, tell your doctor. A blood test can confirm if you have obstetric cholestasis.

Other less common symptoms include:

• Tiredness.
• Poor appetite and feeling sick.
• Mild jaundice. You may go 'yellow' and have dark urine and pale faeces (stools). This is uncommon and due to an increased level of bilirubin (a constituent of bile) leaking from the bile ducts into the bloodstream.

Is obstetric cholestasis serious?

The symptoms can be unpleasant for the mother - in particular the itch. But, whether obstetric cholestasis causes an increased risk of harm to mother or baby is still being debated. If there is a risk, it is thought to be small, but the concerns are as follows.

For the unborn baby

Until recently it had been thought that obstetric cholestasis caused a small increased risk of stillbirth. The risk of stillbirth in a normal pregnancy is about 1 in 100. The risk if you have obstetric cholestasis was thought to be a little more than this. However, this has recently been challenged.

An analysis of the stillbirth figures looking back over a number of years was done in 2006. It concluded that the rate of stillbirth in women with obstetric cholestasis is no different to those without obstetric cholestasis. However, some people feel that the interpretation of these figures depends on whether or not the subjects of the study were being treated for the condition at the time. They say that it is true to say that the rate of stillbirth in women with obstetric cholestasis is no greater than normal if they are actively managed, but that the untreated condition may still pose an increased risk. (Actively managed means medical treatment and/or the close monitoring of the condition of mother and baby, followed by early delivery of the baby - see below.) However, as there is not enough evidence to prove this, the need for early induction of labour, which carries its own risks, is now under question.

More research is currently under way into the risks and effects of the condition and treatment. It is advised that if you have obstetric cholestasis you should consult your care providers.

For the mother

There is possibly an increased risk of serious bleeding from the womb just after giving birth. However, again the studies are not conclusive and there may be no increased risk of this.

How is obstetric cholestasis diagnosed?

The diagnosis is suspected if you develop itch during pregnancy. A blood test can detect the raised level of bile acids and liver enzymes (chemicals) in the blood. Other blood tests may be taken to measure other liver functions and to rule out other causes of liver problems such as viral hepatitis. In some cases the itch develops a week or more before the blood test becomes abnormal. Therefore, if the first blood test is normal then another may be done a week or so later if the itch continues.

The diagnosis is confirmed if you have:

• Itch that is not due to any other known cause (such as a skin disorder), and
• High levels of liver enzymes and/or bile salts in your blood that cannot be explained by any other liver disease such as viral hepatitis.

Both the itch and high level of liver enzymes and bile salts go away after the birth of the baby. A blood test done sometime after the baby is born can confirm this. This sometimes helps to confirm that the diagnosis was, in fact, obstetric cholestasis if there had been any doubt.

What is the treatment for obstetric cholestasis?

There is no cure for obstetric cholestasis. As mentioned, the condition is not usually serious but can be distressing. Symptoms go once you have the baby. The following may be advised by your specialist which may help.

General measures

Some women have found that keeping cool helps to ease the itch. Tips to do this include: lowering the thermostat in your house, keep your body uncovered at night, take cool showers and baths, soak your feet or hands in ice water. These measures may give some temporary relief, particularly before going to bed when the itch may ease enough to allow you to fall asleep. A bland moisturiser cream may also give some temporary relief from itch.

Ursodeoxycholic acid

This is a naturally occurring bile acid and is used as a medication. Strictly speaking, it is not licensed for pregnant women, but has often been prescribed. The logic is that taking this drug may help to improve the function of the liver and help to reduce the bile acid level in the bloodstream. This may then ease symptoms (and may possibly reduce any possible increased risk of pregnancy complications).

However, the research evidence to support the use of this drug is not strong. Whilst some doctors believe it helps, some small studies have concluded that it does not help. A current national guideline on obstetric cholestasis states ... "there are insufficient data to support the widespread use of ursodeoxycholic acid (UDCA) outside of clinical trials." So, it is a treatment that is being studied and may be used, but more research is needed to clarify if it is helpful or not.

Vitamin K supplements

These are commonly prescribed. Vitamin K is essential for the blood clotting mechanism to work. Sometimes the level is reduced in people with liver and bile problems. So, it seems sensible to make sure that you do not lack this vitamin. This is why supplements are often advised.

Regular ante-natal checks

You may be advised to have ante-natal checks more often than usual to monitor the progress of your baby carefully.

Deciding about early delivery of the baby

Until recently it was thought that there was an increased risk of stillbirth with obstetric cholestasis. Because of this, many specialists advised to induce labour so that you would give birth early - at 37 weeks of pregnancy. However, as discussed above, the concern about an increased risk of stillbirth is debatable. So, the practice of early delivery is under review and may be revised. Your specialist can advise about the most up to date thinking and practice about this.

Further sources of information and help

Obstetric Cholestasis Support Website

Web: www.ocsupport.org.uk
Provides support and information to mothers who have, or who may have, the condition. Keeps abreast of the most recent research into the condition.

British Liver Trust

2 Southampton Road Ringwood BH24 1HY
Tel (helpline): 0800 652 7330 Web: www.britishlivertrust.org.uk