A Revolution in Making Babies

By Philip Elmer-DeWitt

For hundreds of thousands of years, there was only one way to make a baby, at least for humans. Either it worked or it didn't, and if it didn't, there was little anyone could do about it. All that has changed dramatically. The growing problem of infertility -- exacerbated by a generation of would-be parents who put off having babies until their 30s and 40s -- and the early successes of in-vitro ("test tube") fertilization have laid the groundwork for a revolution in reproductive technology. Hardly a week goes by without news of a breakthrough to help nature take its course. Last week produced two such announcements: one offers new hope to women with blocked Fallopian tubes; the other promises to extend women's fertility beyond their prime childbearing years -- even past menopause.

Of all the barriers to pregnancy, menopause, which shuts down the release of eggs from the ovaries, was long considered the most insurmountable. But though the ovaries may shrivel like raisins, the other reproductive organs of postmenopausal women are still viable. These women can now become pregnant using someone else's eggs, according to a remarkable report in last week's New England Journal of Medicine. A team led by Dr. Mark Sauer of the University of Southern California impregnated six of seven postmenopausal women, ages 40 to 44, using eggs that were taken from younger women and fertilized with sperm from the older women's husbands. Four of these prematurely menopausal women gave birth to healthy offspring, one miscarried, and one had a stillborn baby -- an outcome that Sauer said would have been considered normal with six younger women.

"The limits on the childbearing years are now anyone's guess," wrote Dr. Marcia Angell in an accompanying editorial. Theoretically, donor eggs could allow women whose ovaries have stopped functioning to bear children into their late 40s and 50s. Researchers believe that the new technique will have the biggest impact on women in their 40s who have not yet reached menopause but have failed to conceive. The new findings suggest that these women may be infertile not because their uteruses are too old but because their ovaries . are, and that with eggs donated by younger women their chances of getting pregnant may be as good as those of the young women themselves. The hitch is, of course, that the children developing from such eggs have the genes of the female donor and are genetically unrelated to the mother who bears them -- a fact that presents both legal and ethical problems as yet unresolved.

The other report issued last week focuses attention on the Fallopian tubes, the narrow passages that carry eggs from the ovaries to the uterus. Women whose tubes are clogged with scar tissue or other obstructions cannot conceive by natural means because their eggs have no way of getting to the womb. In the past, such women had to undergo surgery to have their tubes cleared. Now the problem can be overcome in a doctor's office, according to an article in the Journal of the American Medical Association. With a tiny balloon similar to those used to clear blocked arteries, scientists were able to unclog the Fallopian tubes in 64 of 77 women, 22 became pregnant within a year. Dr. Edmond Confino, who pioneered the technique at Mount Sinai Hospital Medical Center in Chicago, estimates that it could help nearly one-third of the 1 million American women who suffer from blocked tubes.

The new methods join an array of novel techniques that seem to multiply faster than test-tube babies. Most are variations on the pioneering procedure known as in-vitro fertilization. In IVF, eggs are removed from the ovaries, mixed with sperm in a laboratory dish, allowed to develop into embryos and then inserted into the uterus. The technique has produced 20,000 offspring since 1978.

But even at well-run clinics, the original IVF procedure fails 75% to 85% of the time. The biggest snag comes when the embryo is inserted in the uterus, an operation that can be very disruptive to the womb. As a result, such embryos often fail to take root, or implant. To increase the chances of implantation, many doctors are now inserting egg and sperm into the Fallopian tube, a procedure known as GIFT (for gamete intra-Fallopian transfer). Fertilization takes place not in a laboratory dish but in the Fallopian tube, as it would naturally, and the resulting embryo drifts gently into the uterus, where it is much more likely to be successfully received. In yet another variation, called ZIFT (for zygote intra-Fallopian transfer), the sperm are allowed to fertilize the eggs before transfer to the Fallopian tube. The advantage: only those eggs that are successfully fertilized need be transferred.

GIFT and ZIFT have turned out to be breakthrough procedures. Some doctors who have switched from standard IVF to the new techniques have doubled their success rates, which now approach 50%. As the odds have improved, the demand for IVF has surged, despite the high cost (up to $8,000 a try) and the uneven quality of the clinics offering the service.

The proliferation of new IVF methods has produced a crop of books to help infertile couples, from Gay Becker's psychologically oriented Healing the Infertile Family (Bantam; $12.95) to how-to manuals like The Couple's Guide to Fertility by Dr. Gary Berger, Dr. Marc Goldstein and Mark Fuerst (Doubleday; $14.95). One book sure to cause a stir when it appears next January is the new edition of Dr. Sherman Silber's classic 1980 primer How to Get Pregnant. In the revised version, titled How to Get Pregnant with the New Technology (Warner; $21.95), the author repudiates much of the advice he gave 10 years ago.

At that time, Silber recommended that couples exhaust every other means before turning to IVF. Now Silber maintains that the chances of success with state-of-the-art techniques like GIFT are so good that almost anything else is a waste of money and time. Among the practices he attacks are some of today's most widely performed infertility treatments, including operations to remove varicose veins from the testicles of infertile men and procedures to excise tiny lesions in women suffering from endometriosis. Such techniques may be good for financing summer homes for doctors, says Silber, but they are no longer the best way to give infertile couples what they really want: a healthy baby.