Miscarriage

In New Zealand, the term 'miscarriage' is used to define a pregnancy which is lost before completion of the 20th week, or which results in the delivery of a baby not born alive and weighing less than 400g. 

It is estimated that around 1 in 5 pregnancies end in miscarriage, although some experts believe this is a conservative guess as some pregnancies are lost before the mother is even aware she is pregnant. Most miscarriages occur during the first trimester and the risk of miscarriage is highest between 4 and 6 weeks.  The risk drops sharply after around 8 weeks of pregnancy - once a heartbeat is seen on ultrasound there is less than a 5% chance of miscarriage.