An abortion is the termination of a pregnancy by the removal or expulsion of a fetus/embryo from the uterus, resulting in or caused by its death. An abortion can occur spontaneously due tocomplications 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) istermed 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, whilespontaneous abortions are usually termed miscarriages.
Abortion has a long history and has been induced by various methods including herbal abortifacients, the use of sharpened tools, physical traumaand other traditional methods. Contemporary medicine utilizes medications and surgical procedures to induce abortion. The legality, prevalence, and cultural views on abortion vary substantially aroundthe world. In many parts of the world there is prominent and divisive public controversy over the ethical and legal issues of abortion.
Spontaneous abortion (also known asmiscarriage) is the expulsion of an embryo or fetus due to accidental trauma or natural causes before approximately the 22nd week of gestation; the definition by gestational age varies by country. Mostmiscarriages are due to incorrect replication of chromosomes; they can also be caused by environmental factors. A pregnancy that ends before 37 weeks of gestation resulting in a live-born infant isknown as a "premature birth". When a fetus dies in utero after about 22 weeks, or during delivery, it is usually termed "stillborn". Premature births and stillbirths are generally not considered to bemiscarriages although usage of these terms can sometimes overlap.
Between 10% and 50% of pregnancies end in clinically apparent miscarriage, depending upon the age and health of the pregnant...