What are the common causes of miscarriage?
Causes of miscarriage can be broken up into two categories, genetic and environmental. By far the most common cause is genetic with 70-85% of miscarriages resulting when embryos that were genetically abnormal (too few or too many genes) failed to develop beyond the first trimester. Genetically abnormal embryos result from mistakes in cell division occurring in the egg and sperm cells which must first divide in half and then fuse together to form an entirely new person. Mistakes are extremely common with up to 75% of pregnancies ending in miscarriage—many before they are even noticed. As the parents age (especially beyond 35 for women and 55 for men, the number of these mistakes increases). Environmental causes are far less common, but are important, because would-be parents can do something about them. An abnormal uterine cavity, such as one containing a septum (dividing membrane) or a fibroid (benign tumors) can cause miscarriages when the embryo fails to receive an adequate blood sup
