

What Is Test-Tube Birth?

Rev. John Gawrisch

The term "test-tube birth" is, at best, a poorly chosen one. It leads people to believe that some doctor kept a fetus alive in a giant test tube and carefully watched it grow for nine months until birth. Nothing could be further from the truth.

The more correct term used by doctors and scientists for this technique is in vitro fertilization, hereafter referred to as IVF, had its inception in 1955 with Landrum B. Shettles, a physician previously associated with Columbia College of Physicians and Surgeons, and now pursuing even more controversial medical research in Randolph, Vermont, human cloning.

In 1966, a physiologist at Cambridge University in England, Robert G. Edwards, started pursuing human IVF seriously. By 1969, he had found a culture medium that improved the chances of fertilization of an egg in tissue culture. In 1970, he began working with Patrick C. Steptoe, a gynecologist at Oldham General Hospital in England. The two together made further progress so that by 1978, they finally got a human egg, fertilized in a petri dish with the father’s sperm, to reimplant in its mother’s womb and grow to term. Clifford Grobstein, referring to the great amount of time spent on IVF before the goal was reached, states:

It was the growing understanding, in the past 25 years or so, of the complex processes by which internal fertilization and development are normally accomplished in mammals and specifically in human beings that made external fertilization possible. (Clifford Grobstein, "External Human Fertilization," Scientific American, Vol.240, No.6 - June1979, p.57)

The method for IVF is not as difficult to explain as it was to discover. Needed are ripe eggs ready for fertilization, sperm, a system to bring the two together, and a medium that will support early stages of embryonic development.

To obtain the ripe eggs, the prospective mother is given a precisely regulated dose of a reproductive hormone known as HCG (human chorionic gonadotropin) that stimulates her ovaries to prepare eggs for release. About thirty hours later, the eggs are ready for the harvest. Timing is crucial here because if too much time passes, the eggs will be released from the ovaries by natural means and be unrecoverable.

The woman is given general anesthesia. A small incision is made under her navel and an instrument called a laparoscope, designed by Dr. Steptoe, is inserted. The laparoscope is a long metal tube containing a light and an optical lens. Using it, the physician can view the ovaries directly.

Ripened eggs cause the thin walls of the ovary to bulge. The wall is punctured, and the egg is removed by suction. Most women undergoing this treatment have between one and three eggs, all of which are surgically removed. Because the injected hormone causes more eggs to ripen, the procedure is sometimes labeled superovulation. By the way, this is the reason why multiple births occur so frequently with women who have undergone reproductive therapy. To remove one egg takes approximately 8.5 seconds.

Before laparoscopy, the woman’s husband provides a quantity of sperm. From all information that the writer has been able to acquire, the husband provides the sperm exclusive of sexual intercourse. The sperm is then washed and diluted. Sterile techniques must be followed to prevent contamination or infection in the culture medium. Dilution of the sperm simulates conditions in the fallopian tubes where fertilization occurs naturally.

The sperm are next placed in a salt-water solution, again to simulate the female reproductive tract, where in a few hours, they undergo a chemical change called capacitation that prepares sperm to fertilize the egg. Droplets of the solution containing the sperm are placed in a dish partially filled with an inert oil. The sperm-droplets sink to the bottom of the dish. One egg is pipetted into one of these droplets; the droplet keeps the sperm and egg confined within a small volume.

If all goes according to schedule, fertilization occurs a few hours later. After twelve hours, the embryo is transferred to a solution that supports its development.

In two more days, the fertilized egg has become an 8-celled embryo; after four days, it is an approximately 100-celled embryo called a blastocyst. Sometime between two and four days after fertilization, the developing embryo is inserted into the uterus of the woman. Before insertion, the woman has been treated with additional hormones to prepare her uterus for implantation. The whole process of hormone therapy is regulated by the frequent analysis of maternal blood samples. Because the size of an embryo when it normally enters the uterus and implants on the uterine wall is not known, no one knows the ideal time for inserting the embryo. This has been, and still is, the major hurdle in IVF. "The difficulty is not encountered in fertilizing the eggs and supporting the initial stages of embryonic development. Rather, it is in inducing the embryo to become implanted in the uterus." (George H. Kieffer, "IVF - In Vitro Fertilization," The American Biology Teacher, Vol.42, No.4 - April 1980, p.212). The numerous failures before 1978 are thought to be due to the fact that only blastocyst embryos were inserted into the uterus. Steptoe and Edwards inserted an 8-celled embryo that did implant. If this is actually what happened, it is contrary to what was formerly believed about the biology of implantation.

In any case, the embryo is inserted by drawing it up into a fine tube which is then placed into the cervix and then is expelled into the prepared uterine cavity. If all goes well, the embryo may implant through natural processes. Approximately nine months later, a baby will be born.

To date (1980), three in vitro fertilizations and embryo transplants have been successful. The first, Louise Joy Brown (five pounds 12 ounces), was born July 25, 1978 at Oldham General Hospital, England. Her birth was the most widely publicized. Since her birth, two others have been reported; one in Glasglow, Scotland, and the other in Calcutta, India. All three children, two girls and a boy, are supposedly in perfect health, but each stage of their development will be observed closely.

Says Dr. Steptoe: "In a reasonable number of years, instead of this being a wonder, it’ll be a reasonably commonplace affair" (The Christian Century, "Test-Tube Conception: Troubling Issues," Vol.95 No.26, August 16-23, 1978, p.758). Even so says his associate, Dr. Edwards: "We’re at the end of the beginning, not the beginning of the end" (Ibid.).

And in summary concerning the technique, Dr. Steptoe states in a Cleveland newspaper, The Plain Dealer: "We are not creating life. We have merely done what many people try to do in all kinds of medicine, to help nature" (The Plain Dealer, Cleveland, Ohio, July 27, 1978).

Next: Who Benefits from IVF?

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