OBSTETRIC CHOLESTASIS

Obstetric cholestasis, also known as intrahepatic cholestasis of pregnancy, is a condition of the liver occurring specifically during pregnancy. It causes a build up of bile acids in the bloodstream. The main symptom is persistent itch in the late second or third trimester. There is possibly a small increased risk of complications of pregnancy, but the evidence for this is not conclusive. Symptoms go soon after delivery. Some treatments may help to ease the itch.

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 known as intrahepatic cholestasis of pregnancy.

Obstetric cholestasis occurs in about 1% of pregnancies.⁰²⁰¹ In the UK the incidence in the white population is 0.6% and this is doubled in women from the Indian subcontinent. It is more common in women carrying twins, triplets, or more. Mothers 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 especially Chile and Bolivia where up to 1 in 20 or more pregnant women develop this condition. This would suggest that a strong genetic predisposition If you have obstetric cholestasis in one pregnancy, you have a high chance that it will occur in future pregnancies.

Causation

The exact cause is not known. Hormonal and genetic factors play a part.

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 cause a much reduced flow of bile.

Within a week or so after giving birth the symptoms clear and there is no long term problem with the liver.

Symptoms

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

Itch 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.

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.
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.

Effects

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.
For the fetus -There is an increased chance of premature delivery, caesarean section and need for care of the baby in the special care baby unit.⁹⁹⁰¹In a study of 352 affected women 23 (7%) were complicated by intrauterine death (20 singletons and 3 twins) and 133 (38%) were delivered prematurely (56 spontaneous and 77 iatrogenic).⁰⁴⁰¹ Eighteen of the 20 singleton intrauterine deaths occurred after 37 weeks. All three intrauterine deaths in twin pregnancies occurred before 37 weeks. The current rate of stillbirths is comparable to that in the general population.⁰⁶⁰¹

Diagnosis

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.

It is reasonable to measure liver function tests (LFTs) weekly and to confirm resolution of the abnormalities at least 10 days after delivery.

Treatment

There is no cure for obstetric cholestasis. Management requires alleviation of pruritus for the mother and increased vigilance to reduce the risks for the baby. The efficacy of conventional fetal monitoring has yet to be proven.^{9601, 0601}

General measures
Some women have found that keeping cool helps to ease the itch. 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 medicine 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 reduce any possible increased risk of pregnancy complications. Some studies claim benefits.⁹⁸⁰¹However, there are insufficient data to support the widespread use of ursodeoxycholic acid (UDCA) outside of clinical trials.⁰⁶⁰¹

Vitamin K supplements
Vitamin K is essential for the blood clotting mechanism to work. Sometimes the level is reduced in people with liver and bile problems.

Regular ante-natal checks
As with any compication during pregnancy, ante-natal checks are scheduled more often.

Delivery
In the study by Heinonen and Kirkinen⁰²⁰¹ elective delivery at 37 weeks reduced the stillbirth rate without increasing the caesarean section rate. More data are required to support or refute the popular practice of delivery at 37 weeks to reduce late stillbirth.⁰⁶⁰¹

Links to reference abstracts.

Women's Health

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This is the personal website of David A Viniker MD FRCOG, Consultant Obstetrician and Gynaecologist at Whipps Cross University Hospital, London - Specialist Interests - Reproductive Medicine including Infertility, PCOS, PMS, Menopause and HRT.

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Obstetric Cholestasis