A deficiency leads to accumulation of these fatty acids in the liver. ICP is due to abnormal biliary transport resulting in saturation of the hepatic transport system. Fortunately, these are rare complications of pregnancy, with incidences of 1 in 40, and 1 in , deliveries. A Cochrane review found that UDCA improves pruritus over placebo, [ 32 ] and some trials have demonstrated improvement in liver enzymes and have enabled delivery to occur closer to term. Perinatal transmission does occur, but rates are still unknown. Patients who test positive should be counseled regarding methods to decrease the risk of transmission to others, including not donating any blood, semen, or serum and covering all open wounds.