Contraception

1
Contraception

• against conception
• methods
• prevent sperm from fertilizing ovum
• prevent transport of conceptus through oviduct
• prevent implantation

2
Female Sterilization Tubal Ligation

• performed by laparoscopy under anesthesia
• oviduct is cut and tied
• risks ectopic pregnancies

3
Male SterilizationVasectomy

• Can be performed on an outpatient basis
• Local anesthesia is administered
• Vas deferentia are severed and tied off
• Does not interfere with testosterone production

4
Birth control pills history

• most popular reversible form of contraception
• idea for the pill was first conceived in Europe
  in late 1890s!
• in 1960, FDA approved the combination pill

5
Combination pill

• over 30 different brands currently available
• all contain synthetic estrogen and progesterone
• failure rate is less than 1

6
Comb. Pill, contd.

• hormones act in negative feedback manner to
  prevent LH surge (and thus ovulation)
• even if pill fails to prevent ovulation, cervical
  mucus is hostile to sperm transport
• even if fert. occurs, endometrium is unreceptive
  to embryo

7
Use of the pill

• first 21 pills contain E and P (suppress
  ovulation)
• last 7 pills are inert uterine lining shed
• pregnancy doesnt occur during last week since
  its not enough time for follicular growth and
  ovulation

8
Other pills

• sequential pill (Triphasic 7/7/7) pills during
  early cycle contain only estrogen then, E P

9
Minipill

• Daily prog
• can block ovulation
• major effects are
• to make cervical mucus hostile to sperm
• prevent implantation if fert. occurs
• cycle length varies

10
Minipill

• breakthrough bleeding often occurs
• failure rate is higher than with combination pill
  (between 0.5 - 10)
• usually used when a woman should not take E (e.g.
  cardiovascular disease)
• adverse effects risk of ectopic pregnancy

11
Adverse side effects of combination pill

• estrogen-related adverse effects
• nausea, vomiting
• fluid retention, weight gain (?)
• headaches
• engorgement of veins with blood
• breast tenderness
• brown spots on the face
• changes in vision
• increased blood pressure

12
Adverse effects, contd.

• progesterone-related side effects
• increased appetite
• breakthrough bleeding
• depression (?)
• rarely, hair loss

13
Does the pill cause cancer?

• recent study by U.S. CDC showed no risk of breast
  cancer
• long-term use (8 yrs or more) may increase risk
  (by 2.4 times) of cervical cancer
• may slightly increase risk of liver cancer

14
Effects of pill on cardiovascular system

• Increased risk of blood clots
• risk is greatest for
• those over 35
• those with other risk factors (hypertension)
• smokers (78 X!)
• despite warnings, 30-40 of pill users in U.S.
  still smoke

15
Benefits of combination pill

• pill users show decreased incidence of ovarian
  and endometrial cancer
• convenient (but remember doesnt prevent STDs)
• low failure rate low cost

16
Other combined hormone methods

• Vaginal ring
• The patch
• http//www.plannedparenthood.org/bc/cchoices.html

17
Norplant

• approved for use in U.S. in 1991
• intradermal implantation of progesterone
  capsules
• lasts 5 yrs.
• mechanism of action is similar to the minipill

18
Norplant

• side effects prolonged uterine bleeding, weight
  gain, headaches, increased risk of ectopic
  pregnancy
• advantages convenient, may lower blood
  cholesterol, failure rate is as low as
  combination pill
• recent complaints removal is painful, leaves
  scars and possibly nerve, muscle damage

19
Injectable progestogens

• used in other countries since late 1950s
• recently approved for use in U.S.
• injected every 90 days blocks LH surge
• failure rate is similar to that of the
  combination pill
• side effects like Norplant

20
Intrauterine devices

• small piece of molded plastic inserted into the
  uterus by physician
• mechanism of action?? probably prevents
  implantation
• IUD recognized as foreign body in uterus
• causes inflammation
• idea first conceived in 1800s by Arabs and Turks
  (pebbles in camel uterus)

21
IUDs

• physician inserts through cervix, into uterus
• nylon thread extends into vagina
• side effects expulsion, pain, bleeding
• risks perforation of uterus, increased PID risk
• failure rate is similar to that of combination
  pill
• Dalkon Shield incident has made manufacturers
  reluctant to market IUDs