It has been found that mothers of patients with this disease have a higher incidence of ICP, suggesting that heterozygote carriers of these mutations are also predisposed to ICP.In addition to genetic changes to bile salt transport molecules, high levels of estrogen glucuronides have been shown to inhibit the bile salt export pump (BSEP) ABCB11, and high levels of progesterone to inhibit the ABCB4 (MDR3) phospholipid transporter.Consequently, both genetic mutations in hepatocyte proteins involved in bile secretion together with inhibition of those proteins by high levels of hormone metabolites in pregnancy may have roles in the pathogenesis of ICP. Environmental factors
A number of features of ICP suggest that environmental factors also have a role in the disease:

It has been reported that the incidence of ICP is higher in winter than summer. The incidence of ICP in Chile has dropped from 14% of pregnancies before 1975 to 4% in 2016. ICP recurs in between 60% and 90% of subsequent pregnancies. Low serum selenium levels have been linked to ICP, although the role of selenium in bile secretion is not known. Diagnosis
ICP is diagnosed by blood tests including a serum bile acid test and liver function test. While most pregnant women experience some itch from time to time, itching without a visible rash, or persistent or extensive itch symptoms should be reported to the midwife or obstetrician.
Intrahepatic cholestasis of pregnancy (ICP), also known as obstetric cholestasis, cholestasis of pregnancy, jaundice of pregnancy, and prurigo gravidarum, is a medical condition in which cholestasis occurs during pregnancy. It typically presents with itching and can lead to complications for both mother and baby. Pruritus (itching) is a common symptom of pregnancy, affecting around 23% of women. The majority of times, itching is a minor annoyance caused by changes to the skin, especially that of the abdomen. However, there are instances when itching may be a symptom of ICP. Although typically noticed on the palms of the hands and the soles of the feet, the itching can occur anywhere on the body. ICP occurs most commonly in the third trimester, but can begin at any time during the pregnancy. Signs and symptoms
Most women with this condition present in the third trimester (although it can present as early as seven weeks) with itching without a rash. Typically, the itching is localized to the palms of the hands and soles of the feet, but can be anywhere on the body. Hallmarks of ICP include the following symptoms:Most common:

Itching, in particular but not limited to that of the palms of the hands and soles of the feet, without presence of a rash
Itching that is more noticeable in the evening
Darker urineLess common:

Lighter stools
Increased clotting time (due to possibly associated vitamin K deficiency)
Fatigue
Increased nausea
Decrease in appetite
Jaundice (less than 10% of women)
Upper right quadrant painNot all ICP sufferers have all of the above symptoms.