It’s estimated that around 10-20% of pregnancies end in miscarriage. But some studies suggest that the actual rate of early pregnancy losses could be as high as between 60-75% of conceptions – with the vast majority happening before a woman realises she is pregnant.
However, the rate of miscarriage does increase as women get older. Read more about age and fertility.
It’s important to remember that there is almost always nothing that could have been done to prevent a pregnancy being lost and nothing that can be done to hang on to a pregnancy that is destined to end in miscarriage.
The vast majority of miscarriages are unexplained, partly because they are not usually investigated until a woman has two or three in a row. A random genetic abnormality is the most common cause of miscarriage.
About 9 out of 10 genetically abnormal pregnancies will not survive past the first trimester. In normal human cells there are 46 chromosomes, which contain DNA and genes. When cells have the wrong number of chromosomes, the error is known as aneuploidy – the best-known example of which is Down syndrome which is the result of having three copies of chromosome 21 instead of the usual two.
While miscarriage is usually a one-time occurrence, up to one in 20 couples experience two miscarriages in a row and one in a hundred suffer three or more – this is known as recurrent miscarriage.
Some of the known causes of recurrent miscarriage are:
- Chromosome abnormalities
- Abnormalities of the uterus
- Blood clotting disorders
- Immune disorders
- Hormonal disorders
- Lifestyle factors such as smoking, alcohol and recreational drugs.
If women have two or more miscarriages in a row, we recommend speaking with a Fertility Specialist so tests can be done to see if there is an underlying cause.
More than half of the time these investigations don’t find any explanation for the miscarriages – and this is good news, as it means a healthy pregnancy is likely to be achieved in the future without medical intervention. Knowing this can help to reduce anxiety around being able to achieve a healthy pregnancy