Some women suffer from an itchy skin during pregnancy. This is usually harmless but it may be a sign of a more serious liver condition called obstetric cholestasis (also known as intrahepatic cholestasis of pregnancy or ICP). This type of liver damage may occur during the second or third trimester of pregnancy.
The risks associated with ICP include an increased risk of premature birth and, before the advent of modern obstetric and new born care, a risk of still births.
ICP also raises the risk of bleeding from the womb in the first few days after the birth. This is called postpartum haemorrhage.
These risks make it important to distinguish between a harmless mild itch and a more serious obstetric cholestasis. 1-5
Symptoms of intrahepatic cholestasis of pregnancy (ICP)
ICP commonly shows up with symptoms of itching. Normally around 1 in 5 women complain of itching during pregnancy, especially in the later and more advanced stages of pregnancy.
The cause in most of these cases remains unexplored. It is thought that the itching is caused in normal pregnancies due to the effect on the liver of high levels of hormones or even the stretching of the skin over the abdomen as the pregnancy progresses.
Usually a lotion (e.g. calamine lotion) with soothing elements is prescribed for this itching and no pills or other drug treatments are needed.
Mild itching is common in pregnancy because of the increased blood supply to the skin. However, when a person has obstetric cholestasis there may be other more serious symptoms like:
intense itching especially bad at night on the arms, legs, palms and soles
loss of appetite
nausea even at later stages of pregnancy
and importantly, jaundice
Jaundice is detected clinically when there is yellowing of whites of eyes and skin. These symptoms may go unnoticed in many women.
Causes of intrahepatic cholestasis of pregnancy (ICP)
ICP is caused when there is a rise of the pigment called bilirubin in blood. Bilirubin is made by the liver and is formed when old red blood cells die and their iron containing pigment haemoglobin is converted to bilirubin.
Normally bilirubin passes into the bile (a yellow liquid released from the gall bladder into the digestive tract) and helps in digestion.
Genetic and hormonal changes play a role in causing obstetric cholestasis. The excess bilirubin in blood is carried around to various organs and tissues and leads to deposition and irritation under the skin causing itching.
Excess bile in the mother’s blood may also put the baby at risk. If uncared for as many as 60 per cent of cases lead to a premature birth of the baby and the fetus is jeopardized with fetal distress in up to 33 per cent.
Still birth may be seen in 2% cases. Obstetric cholestasis doesn't usually cause long-term damage to the liver.
Frequency of intrahepatic cholestasis of pregnancy (ICP)
In Europe, obstetric cholestasis occurs in about 0.1 to 1.5 per cent of pregnancies. In England, about one in 160 women (or less than 1%) are affected with obstetric cholestasis. It is more common among twin and triplet pregnancies.
This condition is more common in some South American countries, such as Bolivia and Chile. There it may affect as many as one in six pregnancies. In fact, among the native Araucanian population in Chile, as many as 28% of all pregnancies, are affected.
Obstetric cholestasis is also slightly more common among women of Indian-Asian or Pakistani origin with three in 200 (1.5%) of women affected. These facts support a genetic cause.
Chances of recurrence of the condition in subsequent pregnancies vary from 40 to 90 per cent. All women who have had one episode of ICP during as pregnancy should be monitored carefully on their subsequent pregnancies.
These women are also advised against using contraceptive pills as they raise the risk of liver damage.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)