gynecology and obstetrics
Induced Abortion
Methods of Induced Abortion
Common methods of inducing abortion are Instrumental evacuation of the uterus after cervical dilation Medication induction (drugs to stimulate uterine contractions) The method used depends in part on the gestational age. Instrumental evacuation can be used for most pregnancies. Drugs can be used for some pregnancies that are < 11 weeks or > 15 weeks. Medical abortion done before 11 weeks may be done on an outpatient basis. Patients who undergo medical abortion after 11 weeks should be observed because heavy bleeding is possible. Uterine surgery (hysterotomy or hysterectomy) is a last resort, which is usually avoided and is associated with higher mortality rates. Hysterotomy also results in a uterine scar, which may rupture in subsequent pregnancies. Typically at < 14 weeks, dilation and suction curettage (D & C) is used, usually with a large-diameter suction cannula inserted into the uterus. At < 9 weeks, manual vacuum aspiration (MVA) can be used. MVA devices are portable, do not require an electrical source, and are quieter than electrical vacuum aspiration (EVA) devices. MVA may also be used to manage spontaneous abortion during early pregnancy. After 9 weeks, EVA is used; it involves attaching a cannula to an electrical vacuum source. At 14 to 24 weeks, dilation and evacuation (D & E) is usually used. Forceps are used to dismember and remove the fetus, and a suction cannula is used to aspirate the amniotic fluid, placenta, and fetal debris. D & E requires more skill and requires more training than do other methods of instrumental evacuation. Often, progressively increasing sizes of tapered dilators are used to dilate the cervix before the procedure. However, depending on gestational age and parity, clinicians may need to use another type of dilator instead of or in addition to tapered dilators to minimize the cervical damage that tapered dilators can cause. Choices include The prostaglandin E1 analog (misoprostol) Osmotic dilators such as laminaria (dried seaweed stems) Misoprostoldilates the cervix by stimulating prostaglandin release.Misoprostolis usually given vaginally or buccally 2 to 4 hours before the procedure. Osmotic dilatorscan be inserted into the cervix and left for ≥ 4 hours (often overnight if the pregnancy is >18 weeks). Osmotic dilators are usually used at > 16 to 18 weeks. Medication abortion can be used for pregnancies of<11 weeks or>15 weeks. If patients have severe anemia, medical induction at>15 weeks should be done only in a hospital so that blood transfusion is readily available. In the United States from 2014 to 2017, medication abortion accounted for 53% of abortions done at < 11 weeks Methods references . For pregnancies of < 10 weeks, regimens include theprogesterone-receptor blockermifepristone(RU 486) and the prostaglandin E1 analogmisoprostol, as follows: Mifepristone200 mg orally, followed bymisoprostol800 mcg buccally at 24 to 48 hours (for pregnancies of 9 to 11 weeks, an additional dose ofmisoprostol800 mcg buccally is taken 4 hours after the initialmisoprostoldose) Bothmifepristoneandmisoprostolmay be self-administered by the patient and do not need to be given at a clinic or hospital. 800 mcg is about 95% effective in pregnancies of 8 to 9 weeks and 87 to 92% effective in pregnancies of > 9 to 11 weeks ( Methods references ). Effectiveness after 9 weeks of gestation is improved with an additional dose of Resolution of the pregnancy can be confirmed by one of the following: Ultrasound follow-up Measurement of beta-hCG on the day of administration and 1 week later A urine pregnancy test 5 weeks after administration After 15 weeks, medication induction takes place in a clinic or hospital. Pretreatment withmifepristone200 mg 24 to 48 hours before induction reduces induction times. Prostaglandins are used to induce abortion. Options include Vaginal prostaglandin E2 (dinoprostone) suppositories Vaginal and buccalmisoprostoltablets IM injections of prostaglandin F2-alpha (dinoprosttromethamine) The typical dose ofmisoprostolis 600 to 800 mcg vaginally, followed by 400 mcg buccally every 3 hours for up to 5 doses. Or, two 200-mcg vaginal tablets ofmisoprostolevery 6 hours can be used; abortion occurs within 48 hours in almost 100% of cases. Adverse effects of prostaglandins include nausea, vomiting, diarrhea, hyperthermia, facial flushing, vasovagal symptoms, bronchospasm, and decreased seizure threshold. 1.Kapp N, Eckersberger E, Lavelanet A, Rodriguez MI: Medical abortion in the late first trimester: A systematic review.MMWR Recomm Rep65 (4):1–66, 2016. doi: 10.15585/mmwr.rr6504a1 2.Jones RK, Jerman J: Abortion Incidence and Service Availability In the United States, 2014.Perspect Sex Reprod Health49(1):17-27, 2017. doi:10.1363/psrh.12015 