Form of abortion

Spontaneous abortion

Main article: Miscarriage

Spontaneous abortions, generally referred to as miscarriages, occur when an embryo or fetus is lost due to natural causes before the 20th week of gestation. A pregnancy that ends earlier than 37 weeks of gestation, if it results in a live-born infant, is known as a "premature birth". When a fetus dies in the uterus at some point late in gestation, beginning at about 20 weeks, or during delivery, it is termed a "stillbirth". Premature births and stillbirths are generally not considered to be miscarriages although usage of these terms can sometimes overlap.

Most miscarriages occur very early in pregnancy. Between 10% and 50% of pregnancies end in miscarriage, depending upon the age and health of the pregnant woman.[10] In most cases, they occur so early in the pregnancy that the woman is not even aware that she was pregnant.

The risk of spontaneous abortion decreases sharply after the 8th week.[11] This risk is greater in those with a known history of several spontaneous abortions or an induced abortion, those with systemic diseases, and those over age 35. Other causes can be infection (of either the woman or fetus), immune response, or serious systemic disease. A spontaneous abortion can also be caused by accidental trauma; intentional trauma to cause miscarriage is considered induced abortion or feticide.

Induced abortion

A pregnancy can be intentionally aborted in many ways. The manner selected depends chiefly upon the gestational age of the fetus, in addition to the legality, regional availability, and doctor-patient preference for specific procedures.