In rare cases, an ectopic pregnancy may occur concurrently with a normal, potentially viable pregnancy. This potentially dangerous condition is known as heterotopic pregnancy.
Spontaneous miscarriage is defined as the loss of a pregnancy before 20 weeks gestation. Most spontaneous miscarriages (75 to 80 per cent) occur in the first 12 weeks of pregnancy.
There are other less common causes of miscarriage. These include: hormonal imbalance, abnormalities of the womb, weakness of the cervix and certain infections like listeria and rubella.
The most common symptom of a miscarriage is vaginal bleeding. This can vary from light spotting or brownish discharge to heavy bleeding and bright red blood.