Egg, meet sperm: An IVF treatment.

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Artificial Wombs and Petri Dish Sperm

While reproductive technology has until now focused on getting more women pregnant, future technology may make it so that they don't actually have to be pregnant. There may come a day when babies grow in artificial wombs that are hooked up to a placenta machine. In 2001, Hun-Chin Liu of Cornell University began growing sheets of endometrial tissue; when the sheets proved too thin to accommodate embryos, she was able to construct a freestanding uterus. When she implanted donated human embryos, they began growing in the tissue much like they would in a woman's womb. The embryos had to be removed, though, due to regulations that limit human fetal growth in a laboratory [source: Reynolds].

In 2003, Liu implanted mouse embryos into an artificial womb; while the embryos almost reached full-term, they ended up deformed, which means this technology has a way to go before women can begin outsourcing the pregnancy process. Still, ethicists are already pondering the implications of artificial wombs. Scott Gelfand of Oklahoma State University told Nature that he could foresee a world in which women who wanted abortions would have to place fetuses in artificial wombs; the resulting children could then be adopted [source: Pearson].

Other scientists are working on growing sperm and eggs in the laboratory. In 2009, researchers at Newcastle University in England announced they had created human sperm cells from embryonic tissue [source: Park]. While the manufactured sperm resembled the real deal in looks and actions, scientists believe that sperm need a 15-year lease in some testes before they're ready to fertilize an egg [source: Park]. For now, researchers envision using the created sperm to study male infertility.

Meanwhile, scientists work on manufacturing eggs and even entire embryos. In the future, it may be possible for two gay men to have a baby together without the help of a surrogate, because eggs can be made from male cells; unfortunately, sperm requires a Y chromosome, leaving lesbian couples to rely on the help of male tissue [source: Adam]. And such a three-parent embryo isn't out of the question -- in 2008, scientists created one for the purpose of eliminating the risk of mitochondrial diseases. The scientists took DNA from the mother and the father, but removed the parts that could foretell a condition like blindness or diabetes. That DNA was implanted into a donor egg which had been scraped of all genetic information except for the tiny bit that does control production of mitochondria, ensuring the fetus ended up with all the genes he or she needed, minus the disease-causing ones [source: BBC].

Will children born without such genetic tinkering end up inferior to the ones born in the lab? For now, we're left with more questions than answers, but as we wonder at the possibilities, science keeps moving forward.