Intrahepatic cholestasis of pregnancy (ICP) is the second most common cause of jaundice in pregnancy. Its prevalence varies from country to country. In the United States, Switzerland, and France ICP occurs in less than 0.5% of pregnancies. However, ICP occurs in 11.8% to 27.6% of pregnancies to women of Araucanian Indian descent in Chile.
The most common symptom of intrahepatic cholestasis of pregnancy is itching which typically develops in the third trimester of pregnancy. The itching begins on the palms and soles, and then spreads to the rest of the body. The rash of ICP is caused by scratching the intensely itchy skin. Jaundice occurs in 10% to 15% of cases and typically develops 2 to 4 weeks after the itching starts. After delivery, both itching and jaundice resolve spontaneously. ICP does recur with subsequent pregnancies in 40% to 50% of women.
Intrahepatic cholestasis of pregnancy is caused by an impairment of bile secretion in the liver. As the bile backs up in the liver, the level of bile acids increases in the bloodstream. These bile acids are deposited in the skin causing the intense itching. Cholesterol, triglyceride, and bilirubin levels are also increased.
Several complicated mechanisms have been proposed to explain this impairment of bile secretion, but it appears that genetic and hormonal factors are involved. Women who have a mother or sister who has had ICP are at a higher risk of developing this condition. Also, estrogen interferes with the clearance of bile from the liver, and progesterone interferes with the clearance of estrogen from the liver.
Women with intrahepatic cholestasis of pregnancy may also experience anorexia, fatigue, greasy stools, dark urine, and epigastric discomfort. Urinary tract infections are more common in women with ICP than unaffected pregnant women. Finally, a deficiency of vitamin K can develop in women who have a prolonged course of ICP.
Intrahepatic cholestasis of pregnancy is diagnosed by blood tests showing elevated levels of bile acids and certain liver enzymes. The presence of itching without a primary rash also helps to confirm the diagnosis. A liver biopsy or ultrasound is rarely needed to establish the diagnosis.
Effect on Baby
The liver of a healthy fetus has a limited ability to remove bile acids from the blood. The fetus normally has to rely on the maternal liver to perform this function. Therefore, the elevated levels of maternal bile cause stress on the fetal liver. Intrahepatic cholestasis of pregnancy increases the risk to the baby of meconium staining during delivery, preterm delivery, and intrauterine death. Women with ICP should be monitored closely, and serious consideration should be given to inducing labor as soon as fetal lung maturity is confirmed.
The itching of ICP can be treated with emollients, antihistamines, soothing baths, primrose oil, and anti-itching products such as Sarna. Medications that aid in bile secretion such as ursodeoxycholic acid (UDCA), cholestyramine, and S-adenosylmethionine have shown variable benefits in reducing itching and bile levels. High dose oral steroids may also be a possible treatment for ICP.