1. Chapter 62
Birth Control 1

2. Birth Control
Interfering with the reproductive process at any step from gametogenesis to nidation (implantation of a fertilized ovum) 2

3. 3

4. Selecting a Birth Control Method
Consider:
Effectiveness
Safety
Personal preference 4

5. Fig. 61-1. Percentage use for birth control methods, United States, 2002.
Note: The segment labeled “other methods” refers to Norplant (no longer used), Lunelle,
contraceptive patches, spermicides, cervical caps, female condoms, and other techniques. 5

6. Oral Contraceptives Mechanism – inhibits ovulation
Classification (two main categories)
Combination oral contraceptives (OCs)
Estrogen and progestin
Progestin-only OCs
Three major subgroups of combination OCs
Monophasic
Biphasic
Triphasic 6

7. Combination Oral Contraceptives – Adverse Effects
Thromboembolic disorders- THIS IS WHY SMOKERS OVER 35 SHOULDN’T USE THEM
Hypertension
Abnormal uterine bleeding
Benign hepatic adenoma
Glucose intolerance 7

8. 8

9. Noncontraceptive Benefits of OCs
Decrease the risk of ovarian cancer, endometrial cancer
Do not increase or decrease risk of breast cancer in average risk women
May decrease risk of ovarian cysts, pelvic inflammatory disease, benign breast disease
Benefit those with iron deficiency anemia, and acne
Favorable effect on menstrual cycles
Reduced cramps; lighter, shorter, and more predictable flow 9

10. Combination Oral Contraceptives – Drug Interactions
Drugs and herbs that reduce the effects of OCs
Rifampin- for treating TB
Ritonavir- protease inhibitor for HIV
Troglitazone
Antiepileptic drugs- consider non-hormonal contraception
St John’s wort 10

11. What to do about a missed pill?
If pill missed in first week: take one ASAP and then continue with the pack. Back-up birth control for 7 days
If 1 or 2 pills missed during 2nd or 3rd week: take one ASAP and then skip placebo week
If 3 or more missed during 2nd or 3rd week: same as for missing 1 or 2 pills, but use back-up birth control for a week

12. Combination Oral Contraceptives – Drug Interactions
Drugs whose effects are reduced by OCs
Warfarin
Insulin
Oral hypoglycemics
Drugs whose effects are increased by OCs
Theophylline
Imipramine
Drugs that elevate potassium should be avoided by patients on yasmin or Yaz- these COCs use drospirenone (aldosterone antagonist) as a progestin 12

13. Combination Contraceptives with Novel Delivery Systems
Transdermal contraceptive patch (OrthoEvra)- contains both estrogen and progestin, patch for 3 weeks, then 1 week off
Contraceptive vaginal ring (NuvaRing) contains both estrogen and progestin, ring for 3 weeks, then on week off, if rings is out >3 hours, need back-up 13

14. Long-Acting Contraceptives
Subdermal etonorgestrel implants (Implanon) progestin only
Depot medroxyprogesterone acetate (MPA)- IM or subQ injection
Intrauterine devices- a progestin one (Mirena) and a non-hormonal one (copper-T)
Spermicides
Barrier devices
Condoms – male and female
Diaphragm 14

15. Drugs for Medical Abortion
Mifepristone (RU 486) with misoprostol
Mifepristone blocks uterine progesterone receptors
Must be administered in first 7 weeks after conception to be effective
Adverse effects
Bleeding
Cramping
Nausea
Vomiting
Diarrhea
Headache 15

16. Drugs for Medical Abortion
Methotrexate with misoprostol
Prostaglandins: misoprostol, carboprost, dinoprostone 16

17. Emergency Contraception
Contraception implemented after intercourse
Following assault, failed contraception, or failure to use contraception
Plan B One-Step: one high-dose (1.5 mg) tab of levonorgestrel within 72 hours
Plan B
2 high-dose tablets of levonorgestrel (progestin)
1 tablet within 72 hours and another 12 hours later
Alternatives to Plan B (ulipristal acetate- progestin agonist/antagonist) 17