Hormonal Contraception

Hormonal Contraception

	▪	1 Oral Contraception
	▪	2 Vaginal and Transdermal Steroid Contraception
	▪	3 Injectable Contraception
	▪	4 Implant Contraception

   Overview

  Hormonal contraceptives using synthetic sex steroids remain the primary methods of nonsurgical birth control around the world. This chapter charts recent progress in delivering contraceptive doses of these steroids by the conventional oral route as well as new approaches using parenteral delivery through injections, transdermal and subdermal, and vaginal and uterine routes. Each route of delivery has particular advantages and disadvantages, but contraceptive success—defined as the avoidance of unintended pregnancy—depends mostly on the predilections and preferences of the user rather than special characteristics of the methods. The wider the selection, the more likely each woman and couple will find a method that will work well in particular circumstances. The proliferation of contraceptive methods over the past several years is a response to the individuality of contraceptive needs and accounts for declining numbers of unintended pregnancies in many places around the world. However, in some countries, such as the United States and most less-developed nations, at least half of pregnancies are unintended; therefore, the development, introduction, and successful use of modern contraceptives still has a long way to go.
Table 1-1 shows contraceptive failure rates achieved in clinical trials, which are the lowest that can be expected, and failure rates among typical users. The age and income of users strongly affect failure rates: users who are younger and those with lower incomes have more contraceptive failures. The intention of users to postpone or avoid additional births (as opposed to a first birth), also affects failure rates, with women who want to avoid additional births having fewer failures than women with no previous births.

TABLE 1-1   - CONTRACEPTIVE FAILURE RATES DURING THE FIRST YEAR OF USE, UNITED STATES

	PERCENTAGE OF WOMEN WITH PREGNANCY
Method	Lowest Expected	Typical
None	85	85
PILLS
Combination pill	0.1	7.6
Progestin only	0.5	3.0
IUDS
Levonorgestrel IUD	0.1	0.1
Copper T 380A	0.6	0.8
IMPLANTS
Six levonorgestrel capsules (Norplant)	0.05	0.2
Two levonorgestrel rods (Jadelle)	0.06	?
One etonogestrel rod (Implanon)	0.01	?
OTHER
Injectable	0.3	3.0
Female sterilization	0.05	0.05
Male sterilization	0. 1	0.15