Contraception Chapter 6
Definition: Contraceptives Conception: the fusion of an ovum and sperm creating a fertilized egg (zygote) Contraception: preventing conception by blocking the female’s egg from uniting with the male’s sperm
Principles of Contraception Based on the physiology of reproduction Types of contraception: Barrier Hormonal Natural methods Surgical Factors affecting choice Advantages and disadvantages
Principles of Contraception Effectiveness Contraceptive failure rate- % of women experiencing an unintended pregnancy in the 1st yr. of contraceptive use Continuation rate- % of people who continue to use the method after a specified period of time
Oral Contraceptives: The Pill Estrogen and progesterone taken orally Mimics the corpus luteum Secretes progesterone & estrogen to suppress ovulation Combination pill Most common Advantages : Easy to use, effective, fertility returns after use Disadvantages : exp. symptoms of pregnancy, no protection against STD’s; stroke, blood clots in older women who smoke
Contraceptive Skin Patch Thin , tiny square patch Releases estrogen and progestin slowly into the bloodstream Prevents the same way as OCs Worn for 1 week, replaced on the same day for 3 consecutive weeks. 4th wk. no patch Advantages: as effective as OCs Disadvantages: similar to OCs
Vaginal Contraceptive Ring The NuvaRing 2 inch flexible vaginal ring molded w/ progestin and estrogen Slowly releases hormones into bloodstream Inserted during cycle, kept in for 3 wks., removed during 4th wk. (ring free) new ring inserted at next menstrual Advantages : 1 month of protection, no daily/weekly action required Disadvantages : similar to OCs and patch
Contraceptive Implants Placed under skin of upper arm/leg Delivers progesterone over a period of years May inhibit ovulation & affect development of the uterine lining Advantages: Highly effective, no further action required after insertion, contain no estrogen, so lower risk of estrogen related side effects Disadvantages: no protection against STDs, menstrual irregularities, uncomfortable appearance
Injectable Contraceptives Depo-Provera Injectable progestin every 12 weeks Provides protection like implants Advantages Highly effective, requires little action on part of user ; No estrogen- related side effects, minor injection Disadvantages: visit to health care facility every 3 months, side effects similar to Norplant, weight gain, infertility after stopping use
Emergency Contraception “Morning-after Pill”, Plan B Most common is the two dose regimen May inhibit/delay ovulation or altering the transport of sperm/egg; do not affect a fertilized, implanted egg Needs to be taken within 72 hours. Best used within 24 hours
The Intrauterine Device (IUD) Small plastic device placed in the uterus ParaGard (copper;protects 10 yrs.) Mirena (protects 5 yrs.) Releases small amounts of progestin May work by preventing fertilization Advantages: highly reliable, once inserted a simple check of string is all that’s needed; reduce risk of endometrial cancer; fertility restored after use Disadvantages: limited to genital tract: heavy menstrual flow, uterine cramping, backache, spontaneous expulsion, may puncture uterine wall
Figure 6.1 An IUD properly positioned in the uterus Figure 6-1: An IUD (Copper T-380A) properly positioned in the uterus.
Barrier methods
Male Condoms Thin latex, or polyurethane Most widely used barrier method Advantages: Protect against pregnancy and STD’s, easy to purchase, no prescription Disadvantages: Most common complaints are reduced sensitivity and interfering with sexual intercourse
Female Condoms Polyurethane sheath with two flexible rings Advantages: offers potentially more protection against genital warts and herpes b/c it covers base of penis as well Disadvantage: more expensive, more difficult to use
Figure 6.3 The female condom properly positioned
Abstinence Abstinence Without sexual intercourse for a chosen period of time Benefits More self respect and respect for others Security that you are not being pursued for sexual reasons. Less worry about STDs and Pregnancy.
The Fertility Awareness Method Only one egg released each month Lives for ~ 24 hrs. unless fertilized Sperm can live in the body for 6-7 days Only 8 days/month when conception can happen FAM Calendar method A woman releases an egg 14-16 days before her next period Temperature method A woman’s BT drops slightly before ovulation and rises slightly after Withdrawal Coitus interruptus
Male Sterilization: Vasectomy Severing of the vas deferens May return to work in 2 days Reversal varies between 80% to 50%
Figure 6.7 Vasectomy Figure 6-7 Vasectomy
Female Sterilization Tubal sterilization (laparoscopy) is most commonly known as tubal ligation Hysterectomy Complication rate: 6-11% Reversibility: Low
Figure 6.8 Tubal sterilization
Which Contraceptive Method is Right for You? Key considerations include: Health risks Implications of unplanned pregnancy STD risk Convenience and comfort level Type of relationship Ease and cost of obtaining and maintaining each method Religious or philosophical beliefs
Contraceptive Effectiveness Most Effective (Perfect Use) Pill, Patch, Ring, Injectiable = 0.3% Implant =0.05% ParaGard = 0.6% Mirena = 0.1% Male Condom =2.0% Female Condom = 5.0% Withdrawal = 4.0 % Vasectomy = 0.1% Tubal sterilization = 0.5%