Lecture Notes, Biology 203, Human Sexuality and Reproduction

Contraception, Sterilization and Abortion, Part 3

  1. Progestin-only contraceptive pills (mini-pills), implants (Norplant), injections (Depo-Provera)
    1. Do not work by inhibiting ovulation only (40-65% ovulate, 15-40% don't ovulate, 20% shift between cycles)
    2. Progestins alter characteristics of endometrium, ovum transport, etc.
    3. Safe for nursing mothers
    4. Irregular or skipped menstruation can be disconcerting for some women
    5. Pills must be taken every day at same time (chance of pregnancy due to missing a pill is greater than with combined BCP's)
    6. Injections (DepoProvera) are given every three months, with a 4-6 week grace period in which to make appointment, average time to conception 6 months)
    7. Implants (Norplant) (6 implants in arm release progestins slowly over 5 years before must be removed, cost $500-700 to insert, average time to conception 1 month)

  1. Sterilization
    1. Should be regarded as permanent--procedures not always reversible
    2. In both sexes, consist of blocking tube (Fallopian tube or vas deferens) to prevent contact between egg and sperm
    3. Men: vasectomy
      1. Usually one or two small incisions through scrotum to reach vas deferens on both sides
      2. Usually loop tied off and removed (procedure)
      3. Done in doctor's (urologist, usually) office with local anesthetic in about 20 minutes
      4. No heavy lifting for 48 hours, tylenol with codeine for pain, one week recovery time
      5. No risk of impotence or reduced sex drive
      6. Not sterile immediately--requires 10 ejaculations and then a sperm count to make sure there are no sperm in semen
      7. 1/2 to 2/3 of men develop anti-sperm antibodies, with no particular consequences
      8. May be reversible, by a good microsurgeon: anatomical success 40-90%, clinical success (pregnancy) 18-60%
      9. One study done in small number of monkeys about 20 yrs. ago showed a slight increase in risk of cardiovascular disease
      10. No risk of death associated with vasectomies (no general anesthetic, no entry into abdominal cavity)
    4. Women: tubal ligation
      1. Block Fallopian tubes with ligation, clips, rings, electrocoagulation (procedure)
      2. Usually done using laparoscope to visualized area and perform ligation (one or two small incisions through abdominal wall)
      3. Done as outpatient in clinic or hospital
      4. More risky than vasectomy because often uses regional or general anesthetic, and involves entry into abdomen
      5. More expensive than vasectomy
      6. Might be reversed by microsurgeon--anatomical success 50-70%, clinical success (pregnancy) 10-50%
    5. Women: hysterectomy
      1. Should not be done just for sterilization--too risky, major surgery
      2. If ovaries removed as well as uterus, lack of estrogen/progesterone will cause early menopause
  2. Induced abortion
    1. If a pregnancy is unwanted, the woman has many choices to make:
      1. She can have the baby and keep it.
      2. She can have the baby and give it up for adoption.
      3. She can abort the pregnancy.
    2. Goal of induced abortion is to remove the products of conception--all embryonic/fetal tissue, including chorionic villi/placenta
    3. Most abortions induced during first trimester (1st 13 weeks) (50% less than 8 wks, 89% less than 13 weeks)
    4. Almost all the rest induced during second trimester (14-24 weeks) (only 1% after 20 weeks)
    5. Risk of death and complications increases with duration of pregnancy, mostly due to type of procedure used for the abortion (see table)
    6. Early medical methods (see table)
      1. RU-486 (mifepristone) given as pills, induces contractions that expel embryo/fetus in 2 days
      2. Methotrexate/misoprostol given as vaginal suppository induces contractions in 5-7 days
      3. Act as anti-progesterones plus prostaglandins
      4. Used in the first to 7th weeks of pregnancy
      5. Effective in 95-6% of women
      6. Complications: one in 8-10 women have week-long uterine bleeding, rarely nausea or diarrhea
    7. Vacuum curettage
      1. Surgical procedure used from 1st to 13th weeks (most common abortion method)
      2. Requires local anesthetic
    8. Dilation and extraction
      1. Surgical procedure used from 13th to 16th weeks
      2. Fetus larger, may require larger curette to remove tissues
      3. May use oxytocin to induce contractions, reduce bleeding
    9. After 20th week, use intact dilation and extraction--more like induced labor, more risky (rare)
    10. Complications: bleeding, cramping, pain, infection (fever, foul vaginal discharge), urinary problems, depression
    11. Rh negative women should have Rhogam shot to prevent Rh disease in subsequent pregnancies
    12. Women may benefit from counseling after abortions
    13. After 2-4 weeks, woman should have pelvic exam to make sure healing is progressing with no sign of infection
    14. Woman should avoid intercourse for two to three weeks, and use some form of contraception
    15. In consultation before abortion, counselor should gather information about menstrual history, reproductive history, allergies, acute/chronic illnesses, pregnancy test, Rh typing, diagnostic tests for STD's
    16. In decade following legalization of abortion (1973), maternal mortality, infant mortality and premature births were all reduced--leveled off since 1985
    17. Many states have introduced legislation to restrict women's choice in various ways
    18. Women choose to abort pregnancies whether legal or illegal--fewer women die from legal abortions than illegal ones.
    19. Never a trivial decision, and hard to be sure of choice until person is in the situation of an unwanted pregnancy