Homocysteine is a type of amino acid that is naturally found in the body. At normal levels, it is not harmful, but elevated levels have been found to be associated with miscarriage as well as heart disease.
An elevated level of homocysteine in the blood results in a condition known as hypercoagulability. The word coagulation refers to blood clotting, and hypercoagulability means that blood clots more easily than it should.
When this occurs in blood vessels, such as the coronary arteries, it may contribute to the clots that block the blood vessels resulting in coronary artery disease.
With pregnancy, it’s thought that these tiny blood clots could instead block blood vessels in the placenta, leading to miscarriage
Elevated homocysteine is not yet proven to cause miscarriage, but there are some commonalities with other conditions which are known to lead to miscarriages. One condition, called antiphospholipid syndrome, may result in both miscarriage and heart disease in an analogous way.