Abortion is the expulsion or extraction of the fetus from the womb before it is viable, usually before the 20th week of gestation. An abortion can occur spontaneously due to complications during pregnancy or can be induced, in humans and other species. In the context of human pregnancies, an abortion induced to preserve the health of the gravida (pregnant female) is termed a therapeutic abortion, while an abortion induced for any other reason is termed an elective abortion. The term abortion most commonly refers to the induced abortion of a human pregnancy, while spontaneous abortions are usually termed miscarriages.
Recurrent pregnancy loss (RPL) or recurrent miscarriage (medically termed habitual abortion) is the occurrence of three consecutive miscarriages. If the proportion of pregnancies ending in miscarriage is 15%, then the probability of two consecutive miscarriages is 2.25% and the probability of three consecutive miscarriages is 0.34%. The occurrence of recurrent pregnancy loss is 1%. A large majority (85%) of women who have had two miscarriages will conceive and carry normally afterwards.