Genetic errors not other causes may be behind nearly all miscarriages

After analysing the tissue of nearly 25,000 miscarriages, researchers found more than half were caused by randomly occurring chromosomal abnormalities, with many of the remaining losses probably being due to undetectable genetic errors

By Alice Klein

More than half of all pregnancy losses are caused by randomly occurring chromosomal abnormalities in embryos and fetuses, according to the biggest study of its kind.

Having a miscarriage is often highly traumatic and can leave people wondering why it happened. One US survey found that 41 per cent of those who lost a pregnancy thought they did something wrong, like lifting heavy objects or being too stressed.

In the past, there was no way of knowing what caused some pregnancies to end, but advances in …