Very rarely, it can cause infection of the womb lining with persistent loss or an offensive odour. If this happens it usually responds well to a short course of antibiotics. When considering this question, it is helpful to ask how often pregnancy occurs on average each cycle. The risk of miscarriage decreases as pregnancy progresses. The risk of miscarriage decreases dramatically after the 8th week as the weeks go by.
Many women miscarry more than once in their life.
Considering the frequency of miscarriage, about 1 in 36 women will have 2 miscarriages due to nothing more than chance. Any miscarriages after that might prompt your doctors to suggest some tests to ensure that it isn't happening for some other reason. If you're worried have a chat with your GP or one of the Gynaecologists. Also see the Recurrent Miscarriage page. Miscarriage may be more common after a previous miscarriage, or less common following previously normal pregnancies.