Lecture Notes, Biology 203, Human Sexuality and Reproduction

Contraception, Sterilization and Abortion, Part 1

  1. Introduction
    1. An Ideal Contraceptive?
      1. 100% safe, 100% effective
      2. Acceptable to everyone willing to use a contraceptive
    2. Concerns that should be addressed when considering use of a contraceptive
      1. Fear of contraceptive technique
      2. Person experience with the contraceptive technique
      3. Expense of using contraceptive
      4. Ethical objections by user or partner to using the contraceptive
      5. Anticipated decrease in pleasure associated with using the contraceptive
      6. Embarrassment associated with using the contraceptive
    3. Patient compliance
      1. Extent to which a patient is willing and able to use a contraceptive as it is intended to be used
      2. Affected by the concerns above, as well as education regarding use of contraceptive
    4. Safety of various contraceptive techniques, compared to other activities (paper and online handout)
    5. Effectiveness of various contraceptive techniques (paper and online handout)
  2. Non-barrier, Non-hormonal Contraceptive Techniques
    1. Douching
      1. Must be done immediately after ejaculation
      2. Sperm take only 15-20 seconds to reach the cervix
      3. Force of water may force some sperm through cervix that wouldn't have reached it on their own
    2. Withdrawal (coitus interruptus)
      1. Withdrawal of penis from vagina just prior to ejaculation
      2. Requires good ejaculatory control by man
      3. Forces him to focus on performance, rather than pleasure or partner
    3. Periodic abstinence (use of various techniques to predict ovulation and avoid intercourse at that time)
      1. Calendar (prediction of ovulation based on a standard menstrual cycle, with ovulation on day 14 after the onset of menstruation)
      2. Measurement of basal body temperature
        1. Measure oral temperature before rising each morning for several cycles
        2. Detection of a 0.3 to 0.5o drop in temperature just before ovulation
        3. Not useful during a febrile illness
      3. Observation of characteristics of cervical mucus
        1. Near ovulation: clear, abundant, elastic, much like egg white
        2. Before ovulation: cloudy, scanty, inelastic, white to yellowish
        3. Second half of cycle: very little present
        4. Sampled by collecting mucus from cervic with fingers
  3. Spermicides (contraceptive foams and suppositories, gels and creams)
    1. Contraceptive foams and suppositories
      1. May be used alone or in combination with some other technique (often condoms)
      2. Contains nonoxynol-9 as spermicidal agent (kills sperm, and also inactivates some viruses)
      3. Comes with applicator used to insert foam into body near cervix
      4. Foams must be shaken to produce foam/bubbles that stay in place to block cervix with spermicide
      5. Suppositories dissolve in cervical fluids; may be gritty or undissolved if little fluid present
      6. Important to insert the right amount, at the right place, at the right time
      7. Lasts 30 minutes
      8. Noncontraceptive benefits (reduction in gonorrhea and trichomonas infections, reduction in cervical cancer (may be due to decrease in STD's), foam provides increased vaginal lubrication
      9. Side effects: occasional allergic reaction, grittiness (supp.), odd taste (oral sex)
      10. Combining two methods (like foam and condom) may increase total effectiveness to that of oral contraceptives
    2. Contraceptive gels and creams--mostly designed to be used with diaphragm or cervical cap rather than on their own
  4. Barrier Contraceptives (often contain or are used with spermicides)
    1. Cervical caps
      1. Heavy latex cup that fits over cervix
      2. Must be fitted by physician (except for pre-sized OTC caps)
      3. Stay in place with suction; removed by breaking suction with finger
    2. Diaphragm
      1. Large latex cup that extends from pubic bone to back of cervix (bigger than cap)
      2. Must be fitted by physician and refitted when weight changes or after pregnancy
      3. Held in place with springs in rim of diaphragm
      4. Inserted and removed with fingers (procedure)
      5. If too large, may press urethra between spring and pubic bone, increasing chance of urinary tract infection
      6. If too small, may slip out of place and allow passage of sperm
      7. Used with spermicidal cream in bottom of cup and around rim
      8. Should be inserted 0 to 6 hours before use
      9. Should be taken out 6 to 12 hours after ejaculation, and at least every 24 hours
      10. Should be removed at least every 24 hours and should be washed and dried
    3. Contraceptive sponge
      1. Polyurethane foam impregnated with spermicide
      2. Dampened before insertion with fingers, removed with ribbon on outer side
      3. One size, available over the counter (OTC)
      4. Effective up to 24 hours, for repeated intercourse
      5. Should not be used during menstruation or vaginal infection
      6. If not used and removed correctly, carries small risk of toxic shock syndrome
      7. Occasional allergies to polyurethane
    4. Female condom
      1. Thin plastic sleeve with smaller ring at inner end that fits over cervix and larger ring on end that extends from woman's body
      2. Lubricated
      3. Outer end should be held in place during insertion of penis for intercourse
    5. Comparison of female barrier contraceptives
      Characteristic Diaphragm Cap Sponge Female Condom
      Fitting requires pelvic exam yes yes no no
      Used with spermicide yes yes yes no
      Spermicide required at time of insertion yes yes no no
      More spermicide required for repeated intercourse yes no no no
      Can be used during menstruation yes no no yes
      Duration of protection (hours) 6 48 24 8
      Longest wear recommended (hours) 24 48 30 8
    6. Male condoms (male options: coitus interruptus, vasectomy, condom)
      1. Safe, cheap, readily available
      2. Reduce incidence of STD's, cervical cancer (in female partners)
      3. Latex condoms offer more protection from STD's than natural ones, which have larger pores that viruses can pass through
      4. Heat sensitive--do not store in billfold or car
      5. Fail when spilled--remove while penis is still erect
      6. Should be fitted over erect penis, leaving 1/2 inch loose at tip if do not have reservoir tip
      7. May come with lubrication--if not, use water-based lubricant like K-Y jelly, not mineral-based like Vaseline
      8. Some men complain of reduced sensitivity, but extra thin condoms improve sensitivity
  5. Intrauterine Devices (IUD's)
    1. Historical...
      1. In common use from 1964 to 1985, and less commonly since 1990
      2. Contraceptive of choice for many older women with established families
      3. Litigation due to uterine infections associated with use of the Dalkon shield reduced use after 1985
      4. Infections led to sterility in some women; bacteria were able to reach uterus by moving along strings
      5. Production of some IUD's resumed, with more restrictions on women who used them
      6. Mortality associated with use of IUD's compared to various other risks
    2. Current usage
      1. IUD's act as irritant to the uterine lining, causing inflammation that interferes with implantation
      2. Many IUD's now on market are T-shaped and have progestins that are released slowly over the life of the IUD (1 or 3 years)
      3. Important that woman regularly check the strings that extend into the vagine from the cervix to make sure that IUD is in place
      4. 5 to 20% of women with IUD's expell them in the first year of use
      5. Complications include bleeding, spotting and cramping, especially in the first few months
      6. Cost $200-300 for IUD that lasts 1 or 3 years
      7. If woman becomes pregnant, the IUD must be removed as soon as possible
      8. Pelvic inflammatory disease (PID) can cause sterility if untreated; IUD must be removed and treatment begun as soon as possible after diagnosis
  6. Hormonal contraceptives
    1. Combined oral contraceptives (most commone type of birth control pills)
      1. Contain both estrogen and progesterone in pills to be taken orally
      2. Estrogen primarily inhibits ovulation (decreases LH and FSH), but also causes changes in the endometrium that make it less receptive to implantation, inhibits ovum transport, and causes degeneration of corpus luteum
      3. Progesterone also inhibits ovulation, but also thickens cervical mucus, changes secretions in Fallopian tubes, and reduces the chance of implantation
      4. Early types of pills had 21 pills with equal amounts of hormones, with or without 7 pills with no hormones
      5. Sequential (or tricyclic) pills (see graph) have varying amounts of hormones to more closely mimic natural hormone production, allowing lower concentrations of hormones to be used
      6. The lower the concentration of estrogen, the fewer side effects, since most are estrogen-related
      7. Advantages of combined birth control pills
        1. Extremely effective
        2. Offer woman control over fertility and menstruation
        3. Safe for most women
        4. Women can take them for many years with no breaks required
        5. Effects are reversible (average time to conceive 3 months)
        6. Reduction of menstrual pain and cramps, ovulatory pain
        7. Reduced incidence of ovarian cysts (by 80-90%), anemia, PID, ovarian and endometrial cancer, ectopic pregnancies (not associated with melanomas)
        8. Variable effect on PMS--worsens in some women, improves in others
      8. Disadvantages of combined BCP's
        1. Must be taken daily (requires good memory, regular schedule)
        2. Expense may be high, depending on where they are prescribed and type (generic $100-130/yr; proprietary $200-300/yr)
        3. Menstrual cycle changes may be disconcerting
        4. May have estrogen-related side effects: nausea, headaches, tender breasts, depression, acne, etc.
        5. Estrogen may increase risk of blood clotting, cause slight increase in blood pressure, but newer pills minimize this
        6. Slight increase in risk of breast cancer and cervical cancer (may be secondary to increased chance of STD's, which may be secondary to increased number of sexual partners
      9. Contraindications (see list)
        1. Women with history of cardiovascular disease (heart attack, stroke, etc.) or clotting disorders should use some other form of birth control
        2. Women with history or close relatives with history of breast cancer should use some other form of birth control
        3. Women with chronic disease related to function of some major organ should consider using some other form of birth control
      10. Danger signs that should be noted by women using combined oral contraceptives
        1. Severe pain in legs, chest, or abdomen
        2. Severe unexplained headaches
        3. Unexplained loss of vision
        4. Reaction: should see physician promptly, stop taking BCP's, use some other form of contraception
      11. Women who are over 35 and smoke should use some other form of contraception (see table)
    2. Progestin-only contraceptive pills (mini-pills), implants, injections
      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)
  7. 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