(9 of 10)
Yet despite the British team's long experience, the procedure had never resulted in a live birth. To bring it off successfully requires scientific ingenuity, surgical dexterity and, some might say, a lot of plain luck. The doctor must remove the egg at the exact moment in the monthly cycle when it has reached maturity. To ensure the success of that crucial initial step, Steptoe and Edwards follow a standard procedure for treating infertility: they administer fertility hormones, like those that have been responsible for the rash of multiple births in recent years. That encourages the ripening of several eggs at one time. To get at the eggs, Steptoe turns to laparoscopy. While the woman is under anesthesia, an incision is made near the navel. Inert gases are pumped into the abdominal cavity to expand it and separate the organs, and the laparoscope is inserted to seek out appropriate eggs, which are then sucked into a small hollow needle.
Unless the extracted eggs and the husband's sperm — usually obtained by masturbation — are kept at the right temperature and pressure, free of contamination and in an appropriate culture medium (salts, nutrients and sometimes blood serum), fertilization will not occur. Explains the University of Pennsylvania's Benjamin G. Brackett: "You don't want the eggs to suspect they are out of the body."
Equally important, the sperm must be primed for fertilization or, in the technical term, capacitated. This means that the chemical inhibitors preventing the sperm from penetrating the egg must be removed from the surface of the sperm. How this trick is accomplished in the body remains a puzzle; some scientists think that the woman's secretions do the job. But in the lab, experimenters usually are able to prime the sperm simply by gently bathing them in a salt solution. There is also the critical matter of timing: neither eggs nor sperm have unlimited lifetimes, nor does the uterus remain receptive for long. So egg and sperm should be quickly brought together.
Even after fertilization, doctors have no assurance that the egg will divide; again the culture medium must be carefully controlled. Some researchers think that the highest rate of success could be achieved if the content of the solution were continually altered as the cells go through stages of division. Finally, when the egg becomes a blastocyst or shortly before, it is ready for implanting. One way this can be done is by picking up the egg, which is still no bigger than the dot at the end of this sentence, with a tiny hollow tube, or pipette, then inserting it through the cervix and into the uterus. If all goes well, it will implant itself in the uterine wall. At least a week must pass before the doctors know if the patient is indeed pregnant.
Since the beginning of their partnership more than a decade ago, Steptoe and Edwards are believed to have attempted in-vitro fertilization and implantation in hundreds of women. In perhaps half of these cases, eggs were fertilized. But successful implantations have been rarer. Shortly before Mrs. Brown was treated last fall, a medical publication quoted Steptoe as saying that of 60 attempted implants, only three showed signs of lasting — one for nine weeks, the others for two. Why the difficulty?