Birth control technology has improved dramatically in the last 25 years. The Draper Fund report from the U.S. National Library of Health Medicine describes advances in oral contraceptives, time-release birth control and IUD techniques that have created safer and more effective contraception. While their primary purpose is to help women avoid pregnancy, some types of contraception can protect against HIV in some instances, notes the Planned Parenthood website.
Types
Sterilization and vasectomies are the most permanent forms of contraception but should not be considered unless the individual is finished having children. The longest-lasting temporary contraceptive is the implant, which is inserted under the skin of the upper arm. It contains progesterone that protects against pregnancy for up to three years.
The contraceptive injection provides a measured dose of progesterone lasting three months and works by preventing the egg from reaching the uterus. The contraceptive patch, meanwhile, includes estrogen and progesterone that disrupt egg placement in the uterus.
Barrier methods, such as the cervical cap, the diaphragm and male and female condoms, do not permit fertilization of the egg. Spermicidal cream kills sperm and is a safe birth control method when used in conjunction with a condom, a cervical cap or a diaphragm.
Functions and Features
The University of Ottawa notes the implant device functions for several years by releasing a continuous, low dose of progestin known as levonorgestrel. This hormone reduces ovulation and thickens body fluids to inhibit sperm movement.
The Depo-Provera injection involves a progestin hormone that affects the body in much the same way as the implant. Products such as the patch and the birth control pill combine estrogen and progesterone to change the uterine tissue and cervical mucus so that an egg will not implant.
The intrauterine device is a plastic or copper T-shaped device that may cause an inflammatory response in the uterus, inhibiting the implantation of an egg. This device does not involve hormones but can lead to pelvic infection. Spermicidal creams work by killing the sperm before they reach the egg, and barrier methods decrease the amount of sperm that reaches the uterus.
Comparisons
The vasectomy and female sterilization processes are not generally reversible, and another form of contraception must be used for the first three months after surgery.
The intrauterine device requires no attention but can cause ectopic pregnancy and pelvic inflammatory disease. The Depo-Provera shot, meanwhile, is safe as long as the individual receives continued injections, according to Planned Parenthood.
The Family Health Institute states that the ring and patches are good contraceptive methods but notes that they must be changed on time and kept in place. The patch and ring have fewer noted side effects than progestin-only contraception.
The birth control pill is effective only if it is taken regularly. Planned Parenthood notes that condoms, used correctly with every sex act, are excellent contraceptive tools and also protect against sexually transmitted diseases.
Efficacy Rates
Statistics from the Planned Parenthood website indicate that the most effective contraception methods are those that decrease pregnancy risks to less than one pregnancy per 100 women each year. The vasectomy, female sterilization, the intrauterine device and contraceptive implants fall into this category.
Breastfeeding, which can suppress ovulation, allows pregnancy in two to eight out of every 100 women, an efficacy rate similar to that of injections, oral contraceptives, progesterone rings and patches. Male and female condoms, diaphragms, cervical caps, the sponge and fertility awareness-based methods result in pregnancies for 15 to 25 out of every 100 women.
The least-effective techniques are the withdrawal method and use of spermicides.
Global Perspective
The United States Agency for International Development is working to promote family planning worldwide. As of late 2010, the progesterone vaginal ring is used in several countries in Latin America, and in India, the government has begun clinical trials to evaluate its efficacy and safety. The Population Council website notes that in small studies, families have accepted this contraceptive option for breastfeeding women. Researchers hope the clinical trial will support the use of the vaginal ring as an effective birth control method for this population.
