An abortion is referred to as an elective or voluntary abortion when it is performed at the request of the woman for non-medical reasons. Confusion sometimes arises over the term "elective" because "elective surgery" generally refers to all scheduled surgery, whether medically necessary or not. Spontaneous
Miscarriage, also known as spontaneous abortion, is the unintentional expulsion of an embryo or fetus before the 24th week of gestation. A pregnancy that ends before 37 weeks of gestation resulting in a live-born infant is a "premature birth" or a "preterm birth". When a fetus dies in utero after viability, or during delivery, it is usually termed "stillborn". Premature births and stillbirths are generally not considered to be miscarriages, although usage of these terms can sometimes overlap.Studies of pregnant women in the US and China have shown that between 40% and 60% of embryos do not progress to birth. The vast majority of miscarriages occur before the woman is aware that she is pregnant, and many pregnancies spontaneously abort before medical practitioners can detect an embryo. Between 15% and 30% of known pregnancies end in clinically apparent miscarriage, depending upon the age and health of the pregnant woman. 80% of these spontaneous abortions happen in the first trimester.The most common cause of spontaneous abortion during the first trimester is chromosomal abnormalities of the embryo or fetus, accounting for at least 50% of sampled early pregnancy losses. Other causes include vascular disease (such as lupus), diabetes, other hormonal problems, infection, and abnormalities of the uterus.
Manual vacuum aspiration (MVA) consists of removing the fetus or embryo, placenta, and membranes by suction using a manual syringe, while electric vacuum aspiration (EVA) uses an electric pump. These techniques can both be used very early in pregnancy. MVA can be used up to 14 weeks but is more often used earlier in the U.S. EVA can be used later.MVA, also known as "mini-suction" and "menstrual extraction" or EVA can be used in very early pregnancy when cervical dilation may not be required. Dilation and curettage (D&C) refers to opening the cervix (dilation) and removing tissue (curettage) via suction or sharp instruments. D&C is a standard gynecological procedure performed for a variety of reasons, including examination of the uterine lining for possible malignancy, investigation of abnormal bleeding, and abortion. The World Health Organization recommends sharp curettage only when suction aspiration is unavailable.Dilation and evacuation (D&E), used after 12 to 16 weeks, consists of opening the cervix and emptying the uterus using surgical instruments and suction. D&E is performed vaginally and does not require an incision. Intact dilation and extraction (D&X) refers to a variant of D&E sometimes used after 18 to 20 weeks when removal of an intact fetus improves surgical safety or for other reasons.Abortion may also be performed surgically by hysterotomy or gravid hysterectomy. Hysterotomy abortion is a procedure similar to a caesarean section and is performed under general anesthesia. It requires a smaller incision than a caesarean section and can be used during later stages of pregnancy.