Roughly 50 million abortions occur annually. Uterine evacuation is the most common surgical method for abortion. Uterine suction is also used to treat molar pregnancy, endometrial biopsy, incomplete abortion, miscarriage, and retained products of conception--each of which can be dangerous to the mother.
Mechanism of Action
Abortion can be induced with a drug, introduction of intra- or extra-amniotic substances, or surgically. Surgical methods include dilation and curettage (D&C), and vacuum aspiration. D&C often requires heavy sedation or general anesthesia and involves the dilation of the cervix and scraping of the inner walls of the uterus. The WHO recommends that vacuum aspiration replace D&C.
Vacuum aspiration can be done under local anesthesia and is typically performed on an outpatient basis in less than 15 minutes. After numbing the cervix, the practitioner inserts a lubricated, sterile plastic cannula into the uterus and connects it to a manual or electric vacuum source which empties the uterine contents. Up to 12 weeks from conception, dilation may not be required. Later abortions often require dilation and larger cannulae.
Current Use in High-Resource Settings
In 2005 in the US, about 87% of the 1.2M abortions were performed surgically, the majority using electric or manual vacuum aspiration. The average cost for the procedure was $413 in the US.
Application in Low-Resource Settings
Manual vacuum aspiration (MVA) has reduced the cost, skill requirements, and infrastructure needs of safe surgical abortion across the developing world. Unlike D&C, which may require a physician, MVA can be performed by midwives and nurses as an outpatient procedure. It does not require electricity, and has relatively low capital costs. As a result, the technology has had relatively high penetration across the developing world, and is now the standard of care in many settings where safe abortion was previously inaccessible. There are at least 8 manufacturers around the world providing MVA technology, varying in cost and quality. As the devices are often re-used, the best models are durable after multiple autoclave cycles (or other sterilization), and support interchangeable cannulae over a range of diameters from about 4mm to 12mm.