Obstetric cholestasis is a rare complication during pregnancy caused by a reduced flow of bile down the bile ducts in the liver, which causes some bile to leak out into the bloodstream. This build-up of bile acids in the bloodstream can cause a persistent itch in the last trimester of pregnancy, especially in your hands and feet. Like so many things, the symptoms go after you have your baby. Obstetric cholestasis is more common in twin pregnancies, although we do not know the exact cause. Often when symptoms appear during pregnancy, we tend to blame hormones. Oestrogen and progesterone hormones can affect the liver by slowing down the rate of bile passing out along the tiny bile ducts. Learn about some of the risks associated with obstetric cholestasis and some things you can do to relieve itching.