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pubmed:otherAbstract |
PIP: Contraceptive development in the US has been halted by all but one company Ortho Pharmaceuticals. The reasons for this are complex and the problem is very serious. Legal and regulatory pressures have taken away the incentive to do research. There are 3 million unwanted pregnancies each year in this country. If contraceptive use were more widespread and the technology was constantly being improved by a highly competitive market, then this number would be much lower. There are several new forms of birth control being studies for use in the US, such as injectables using microspheres or microcapsules which can last for 1, 3, or 6 months, biodegradable pellets that are inserted under the skin of the hip or upper arm slowly release hormones, the vaginal ring which is saturated with time-released hormones and is worm around the opening of the uterus like a diaphragm, transdermal patches which are changed weekly for 3 weeks with a placebo patch to allow menstruation, osmotic pills which gradually release hormones on a lower and less frequent schedule, and vaccines which can immunize women against hormones in the placenta, egg or from sperm. This research is at an early stage. Luteinizing hormone-releasing hormone (LHRH) analogues suppress ovulation by affecting the pituitary gland. This method has the side effect of blocking ovarian production of estrogen and progesterone. Male methods like Inhibit inhibit the production of follicle-stimulating hormone (FSH). Gossypol has been used in China, but one side effect is that it is sometimes irreversible. Outside the US the injectables Depo-Provera and Noristerat are approved in 90 and 40 countries respectively. Norplant is a progesterone releasing implant, made in Finland, that lasts up to 5 years; it was recommended for approval in 1989 by the FDA's Fertility and Maternal Health Drug Advisory Committee RU-486 prevents the cells in the uterus from receiving progesterone, was developed in France. The Filshie clip is a titanium and silicone rubber barrier that blocks the fallopian tubes. Ovablock is a silicone plug that blocks the fallopian tubes and increase reversibility.
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