Early

Abortion before 12 weeks gestation

Late

Abortion between 12 and 20 weeks gestation

Spontaneous

Pregnancy loss at < 20 weeks gestation

• Threatened

Vaginal bleeding occurring before 20 weeks gestation without cervical dilation

• Inevitable

Vaginal bleeding or rupture of the membranes before 20 weeks gestation accompanied by advanced dilation of the cervix

• Incomplete

Dilation of cervix and expulsion of some products of conception

• Complete

Closed cervix after expulsion of all products of conception

• Missed

Death of an embryo or a fetus is confirmed, but there is no bleeding or cervical dilation and the products of conception have not been expelled

• Anembryonic pregnancy (formerly blighted ovum)

Nonviable pregnancy with a gestational sac, but with no yolk sac or embryo visualized on transvaginal ultrasonography

• Recurrent or habitual

≥ 2 to 3 spontaneous abortions

Induced

Interruption of pregnancy with medications or a procedure

Septic

Serious infection of the uterine contents during or shortly before or after an abortion