Methods and Procedures

1.   Medical Abortion (or “Medication Abortion”):  Medical methods of abortion involve the administration of medications to cause cramping and bleeding and passage of the pregnancy. In general, the term “medical abortion” refers to the process in the early first trimester (usually limited to nine weeks) and induction abortion refers to the process in the second trimester.  The process is used less frequently in the later first trimester and early second trimester.  Mifepristone (Danco Laboratories, www.earlyoptionpill.com) is the only medication approved by the FDA for early medical abortion.  It is followed by misoprostol one to three days later to cause cramping and bleeding.  Misoprostol alone or methotrexate+misoprostol sometimes are used when mifepristone is not available.  The FDA-approved regimen relies on evidence from 1995 and earlier.  Subsequently many studies have led to evidence-based regimens.  Organizations have produced guidelines for these evidenced-based regimens to help clinicians feel comfortable evaluating the evidence and changing their protocols or practice.  The evidence-based regimens use a lower dose of mifepristone (200 mg versus the FDA’s 600 mg), home administration of misoprostol as well as alternative routes of administration of misoprostol, such as vaginal, buccal and sublingual routes. Many studies of these alternative regimens report a success rate of over 95%, with a continuing pregnancy rate of less than 0.5%.

2.   Surgical Abortion:  Surgical abortion is the most common term for abortion procedures that use uterine aspiration or evacuation. [1] Vacuum aspiration is the primary method through 12-14 weeks.  Suction is accomplished with a hand-held manual vacuum aspirator (“MVA,” sometimes referred to as manual uterine aspirator, or “MUA”) or an electric suction machine (electric vacuum aspirator, or “EVA”).  Surgical abortion in the second trimester is called “dilation and evacuation” (“D&E”).  Intact D&E or dilation and extraction (“D&X”) is a variation where the fetus is removed mostly intact. (See definitions below.)

3.   Aspiration AbortionAlternative terms used to describe aspiration abortion include the general term surgical abortion (elective or therapeutic), vacuum aspiration, suction curettage, manual vacuum aspiration (“MVA”) and electric vacuum aspiration (“EVA”).   The MVA (also called manual uterine aspirators or Karman syringes) creates up to 60 mmHg of suction and are quiet, small, handheld, and do not require a power source.   The provider closes the valves on the MVA, pulls on the plunger, and creates a vacuum. EVA consists of a plastic hose connected to a bottle on an aspiration machine or wall suction.

These are all methods of surgical abortion that remove the contents of the uterus using suction. MVAs can be used for termination up to 12 weeks gestation, and as part of terminations at later gestations. Many providers choose to

switch to EVAs after about 9 weeks because the MVA must be emptied a few times at earlier gestations. Vacuum aspiration is typically used for first-trimester abortions, but suction may be used to complete early second trimester procedures.

4.   Dilation and Curettage (“D&C”):  A procedure for abortion, miscarriage or diagnosis of uterine pathology in which the cervix is dilated and the walls of the uterus are scraped to remove the contents of the uterus.  D&C is a general term and can refer to vacuum aspiration as well as use of the metal curette. Dilation and sharp curettage typically is used in countries where abortion is illegal and MVAs are not readily accessible. The word “sharp” refers to the metal loop curette used to scrape the inside of the uterus.

5.   Dilation and Evacuation (“D&E”):  A second-trimester surgical abortion procedure that is sometimes referred to as a “standard D&E” in order to distinguish it from an “intact D&E” (see below), which was banned by the Partial-Birth Abortion Ban Act of 2003. The cervix initially is dilated using osmotic dilators and/or misoprostol for a few hours up to 3 days.  (Direct mechanical dilation rarely is used alone in the second trimester because of concern for potential cervical damage.) For this procedure, osmotic dilators, if used, are taken out of the cervix, the amniotic fluid is removed with suction (or by drainage) and then the fetus is extracted using forceps, usually in multiple passes.  This procedure can be performed between 14 weeks and about 25 weeks gestation.  D&Es are the most common method for second-trimester abortion in the U.S.  Based on one study at a training institution, some providers use ultrasound guidance to help monitor the uterus during the procedure.[2]

6.   Dilation and Extraction (“D&X”):  This often is referred to as an “intact D&X” (Dilation and Extraction), or “intact D&E.”  The cervix typically is dilated somewhat more than for a “standard D&E” to enable intact extraction of the fetus from the uterus.  In a D&X, the calvarium (skull) frequently is decompressed before extraction to allow passage through the cervix.  Collapse of the calvarium can be accomplished with forceps or by making a hole in the skull through which the intra-cranial contents are suctioned.  If cervical dilation is sufficient, the provider can extract the entire fetus through the dilated cervix. To achieve this, cervical dilation generally is accomplished with multiple, osmotic dilators over two or more days.  D&X is used as a method of second-trimester abortion and occasionally for early third-trimester terminations. An intact fetus allows more complete evaluation of structural abnormalities and can be an aid to patients grieving a desired pregnancy by providing the opportunity for a final act of bonding.  Removing an intact fetus also reduces the chance of retained fetal tissue in the uterus and minimizes the number of times instruments pass into the uterus, which may reduce the risk of uterine and cervical injury.  This technique most closely approximates what has been characterized legislatively and by the Supreme Court as “partial birth abortion,” a nomenclature that is not recognized in medicine and that applies only if the fetus has cardiac activity.  One study showed that D&X may be somewhat safer than D&E, and it also may be preferable for certain indications, as described above.

7.   Second-Trimester Induction:  The other option for second-trimester termination (other than D&E, D&X or least commonly, hysterotomy) is induction of labor with medications such as misoprostol, other prostaglandins or oxytocin.  Typically the woman is admitted to the hospital for one to four days for induction medications and pain control.  When given 36-48 hours before the start of labor induction, mifepristone shortens the interval for abortion on average by about eight hours.  Several studies have suggested the safety of D&E over second trimester induction; however, this is a good option if there is no experienced D&E provider or if a patient prefers induction termination.

8.   Multi-Fetal Pregnancy Reduction:  Abortion of one or more fetuses while one or more are left viable in the uterus to avoid the considerable risks of multiple gestation (twins or more) or to terminate a fetus with abnormalities while continuing the pregnancy with a normal fetus.  The targeted fetus usually is injected with potassium chloride under ultrasound guidance. The demised fetus is left inside the uterus.  This usually is done between 10 and 13 weeks gestation.



[1]  But see T.A. Weitz, A. Foster, C. Ellertson, D. Grossman, & F.H. Stewart, “Medical” and “Surgical” Abortion: Rethinking the Modifiers, 69 Contraception 77 (2004) (questioning the use of the term “surgical” abortion to describe aspiration procedures).

 

[2]   P. D. Darney & R.L. Sweet, Routine Intraopterative Ultrasonography for Second Trimester Abortion Reduces Incidence of Uterine Perforation, 8 J. Ultrasound Med. 71 (1989)