The Pill. Condoms. Intrauterine devices.
They are staples of modern birth control. And while they represent some of the best options that men and women have at their disposal today to prevent pregnancy, each is decades old -- and comes part and parcel with a number of its own drawbacks.
"We want more choices," says Laura, a 37-year-old Florida woman who preferred that only her first name be used.
"Science has come a long way, but why are contraceptive options lagging behind?"
But researchers are exploring a host of new options for those who are tired of side effects from the pill and wary of the user dependability of condoms. Indeed, some are looking forward to a new wave of contraceptive strategies -- which could well represent the first long strides after the baby steps of progress since the sexual revolution.
One such option, which upon its unveiling garnered chatter in the U.K. press, has generated enthusiasm for the idea of genetic contraception. In fact, it could one day become the first of an "entirely new class of contraceptives," leading researcher Dr. Zev Williams hopes.
Williams, a clinical fellow in the department of obstetrics and gynecology and reproductive medicine at Brigham and Women's Hospital of Harvard Medical School in Boston, presented research at the annual meeting of the American Society for Reproductive Medicine in Washington Tuesday that he says, if successful, "will mark the first serious advance in contraception since the introduction of the birth control pill.
"For the last 60 years, women have had three choices: hormones, the IUD and barrier method -- the condom," Williams says. "The only advancement has been from a nonchewable to a chewable form of the pill, and yet these three options are still all there is.
"We simply don't have a contraceptive drug that is nonhormonal and reversible."
The genetic contraceptive that Williams is developing is based on a concept known as RNA interference (RNAi) -- a process that switches off key genes in a woman's body that play a crucial role in the fertilization of the egg after sex. When these genes are switched off, her partner's sperm cannot enter the egg to fertilize it.
Zev believes that this method will avoid many of the side effects of traditional birth control pills, because it will not flood the body with sex hormones.
"For women who use the pill just as a contraceptive, a nonhormonal approach would be wonderful, says Zev. "You could get all the benefits without the nausea, the headaches, the mood alterations and the raised risk of thrombosis, strokes and heart attacks."
The theory behind genetic contraception builds on similar research among two American scientists, Craig Mello and Andrew Fire -- research that won them the Nobel Prize last year for their work.
If the method works safely in animals, a product could be available within 10 years. While the mode of delivery is yet to be determined, Williams says, it "may be in a vaginal suppository or transdermal form.
"A pill form would be less likely due to acidity in the stomach, which may interfere with the RNAi, but a coated pill may be a possibility," he adds.
However, outside experts say there is much left to be done in terms of research before such a genetic option can become reality.