Word: sperms
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Dates: during 1970-1979
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...wife Doris, 34. Despite several operations, Mrs. Del Zio had apparently been unable to become pregnant because of tubal problems. In 1972, she agreed to let Dr. Landrum Shettles place in her womb an egg said to have been fertilized externally by her husband's sperm. But upon learning of the experiment in his department, Vande Wiele destroyed the specimen, contending that the procedure was risky, that Shettles lacked the skills to undertake it and that it had not been approved by the hospital's committee on human experimentation...
...pioneer in development of the birth control pill, reported that he and colleagues had managed to fertilize an egg in vitro. But other scientists believe that the few cell divisions observed by Rock were nothing more than "parthenogenic cleavage" (division of the egg without the involvement of a sperm), probably induced by incidental stimulation of the ovum. Scientists were similarly skeptical of claims by Shettles in the 1950s that he had brought an externally fertilized human egg into the sixth day of cell division, and by an Italian scientist, Daniele Petrucci, who a few years later announced that...
...1960s did researchers learn how to fertilize mammalian eggs in vitro on a regular basis. The groundwork was laid by M.C. Chang of the Worcester Foundation for Experimental Biology in Shrewsbury, Mass., and C.R. Austin of Cambridge University, who had solved the problem of in-vitro capacitation of rabbit sperm, a process that enabled sperm to penetrate the egg in the laboratory. Until then, the sperm were notably ineffectual in that role. But these early successes 'involved creatures no higher than rabbits, hamsters and mice...
...expelled from its grapelike encasement, or follicle, in the ovary; in any month, either of the female's two ovaries may contribute an ovum. Then the egg enters the nearby fallopian tube. If coitus has taken place, the egg will shortly run into a swarm of tailed sperm that have managed, like salmon battling upstream, to fight their way into this passageway. In a dramatic headlong plunge, a single sperm will penetrate the waiting ovum's outer layer, its 23 chromosomes joining the egg's 23. That produces the full complement of 46 chromosomes, which contain all the genetic instructions...
...journey is precarious. Unless the proper hor mones are present in appropriate concentrations, setting the stage for ovulation and fertilization, this intricate chain of events will not be initiated. The egg will not burst from the ovary, the cervical mucus will be too sticky for the entry of sufficient sperm into the uterus, and the lining of the uterus will not prepare to receive the fertilized egg. Indeed, hormonal disorders at any point in the sequence make it so fraught with peril for eggs and sperm that perhaps a third of all potential pregnancies end at the time of implantation...