Threatened miscarriage

• painless vaginal bleeding occurring before 24 weeks, but typically occurs at 6 - 9 weeks
• the bleeding is often less than menstruation
• cervical os is closed
• complicates up to 25% of all pregnancies

Missed (delayed) miscarriage

• a gestational sac which contains a dead fetus before 20 weeks without the symptoms of expulsion
• mother may have light vaginal bleeding / discharge and the symptoms of pregnancy which disappear. Pain is not usually a feature
• cervical os is closed
• when the gestational sac is > 25 mm and no embryonic/fetal part can be seen it is sometimes described as a 'blighted ovum' or 'anembryonic pregnancy'

Inevitable miscarriage

• heavy bleeding with clots and pain
• cervical os is open

Incomplete miscarriage

• not all products of conception have been expelled
• pain and vaginal bleeding
• cervical os is open