Made-to-Order Baby Created in Hopes of Saving Ailing Sister

Assisted Reproduction and Preimplantation Diagnosis

Document

By: Margaret Taus

Date: 2000

Source: Margaret Taus. "Made-to-order Baby Created in Hopes of Saving Ailing Sister." Associated Press Archive. October 3, 2000.

About the Author: Margaret Taus is a journalist who has written for the Associated Press International and the Seattle Post-Intelligencer, among others.

INTRODUCTION

In the early days of research in the field of reproductive medicine, scientists attempted to understand the causes of infertility, and to correct them surgically or with drug therapies that corrected biochemical abnormalities. Among the earliest invasive and direct fertility enhancing procedures was artificial insemination, in which semen was placed inside the vagina, near the cervix, of a woman who was due to ovulate. As technology advanced, it was possible to use various techniques that could increase the number, or enhance the mobility of healthy sperm to be placed either inside the vagina, or directly into the uterus.

For many women experiencing infertility, which is defined by the Centers for Disease Control and Prevention (CDC) as the inability to become pregnant after a minimum of twelve continuous months of attempting to do so, artificial insemination did not solve their lack of fertility. In addition to the development of several fertility-enhancing pharmaceuticals (the most common first-line drug treatment for infertility is clomiphene citrate, also called Clomid), the procedure for fertilizing a human ovum (egg) outside the body was developed in the 1970s. Termed in vitro fertilization, or IVF, it involved the administration of medications to stabilize the woman's menstrual cycle, followed by medications that increased the number of mature ova (eggs) produced by a woman's ovaries during a particular cycle (typically, the female body releases only one mature egg per menstrual cycle). The eggs were then surgically harvested after ultrasound showed the follicles of the ovary had produced sufficiently mature eggs. Scientists then examined the eggs microscopically to determine their apparent health, and then exposed them to healthy, motile, sperm in a culture medium in the laboratory. The eggs were examined microscopically within a day, and fertilized eggs were allowed to incubate for about three days, in order to undergo successful cell divisions. Because relatively few fertilized eggs actually develop into viable embryos capable of completing a full gestational period, several embryos (often three) would be typically surgically implanted in the uterus, with the hope of a single healthy live birth. A similar procedure to IVF is called GIFT, or gamete intrafallopian transfer, where the harvested eggs and collected sperm are placed in the fallopian tubes immediately after egg harvest, and fertilization (if it occurs) takes place inside the woman's body.

Along with burgeoning technology in other realms came vast improvements in the field of reproductive technology. During the final two decades of the twentieth century, the obstetric subspecialty of assisted reproductive technology (ART) grew exponentially. For the first time, not only could previously infertile couples (frequently) achieve successful pregnancy, they could select for a specific gender, and screen out specific types of genetic abnormalities, assuring that any pregnancies carried to term would be free the genetic abnormalities for which screening techniques exist. This is especially crucial for parents who are known carriers of such heritable disorders as some muscular dystrophies, Tay-Sach's disease, sickle-cell anemia, or cystic fibrosis, among others. With a technology called pre-implantation genetic diagnosis (PGD), it is possible to accomplish detailed genetic screening on a single cell (sometimes two cells are used) from an early embryo that has divided enough times to have at least eight cells or be at the blastocyst stage. At this stage, cells have not yet begun to differentiate and each cell of the blastocyst is genetically identical. The removed cell is genetically mapped to determine whether there are any inherent chromosomal abnormalities indicating the expression of a genetic disorder for which there is a known genetic code. This is sometimes referred to as an embryo biopsy. Those embryos having no evidence of genetic abnormalities (within the bounds of screening ability) are retained; those that are abnormal are destroyed. Of the remaining embryos, a selected number are implanted in the woman's uterus, and the remainders are frozen for potential later use.

A further advance of the use of ART is for screening and development of embryos that are genetically compatible with an older sibling afflicted with a disease, for which a stem cell transplant (typically from umbilical cord blood obtained shortly after birth) might provide a cure.

PRIMARY SOURCE

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SIGNIFICANCE

Since the birth of Adam Nash in 2000, the use of assisted reproductive technology in order to create "made-to-order babies" has garnered much media attention. By the early twenty-first century, families around the globe sought PGD. The procedure is costly and time intensive, which is a deterrent for many parents. In addition, many countries have not yet developed the necessary technology.

The process is not without considerable controversy. For those groups whose religious belief it is that humanhood begins at conception, the destruction of fertilized embryos is anathema; they oppose the IVF process for the same reason. Some opponents would also say that simply possessing the gene for certain heritable disorders does not definitively guarantee that they will be expressed, and that humans should not interfere with the natural order of genetics. Bioethecists express some concerns about potential misuse of the burgeoning technology as a means of eliminating various characteristics that might be outside the desired norm, such as handedness, small stature, or sexual orientation. In all likelihood, the cost, the technology, the time, the risks, and the extreme unlikelihood of third-party payors authorizing large-scale use of PGD will prohibit those concerns from occurring in the near future.

Several genetic disorders, and some forms of cancer, are potentially life-threatening blood disorders that can sometimes be cured by transplants that result in rebuilding the host's immune system. Other disorders, if resistant to conventional therapies, may only be potentially cured by a bone-marrow transplant from a genetically compatible donor. A family with a biological child who has a life-threatening disorder may seek the use of PGD technology in order to conceive an infant who is a suitable donor. By using IVF and PGD, a genetically suitable embryo may be produced and implanted, and may develop into a healthy fetus who can donate stem cells from cord blood. In the case of the Nash family, Adam was born healthy, and was able to donate cord blood to his sister without being subjected to any risk to his health or safety. Molly Nash tolerated the procedure, made a full recovery and has remained healthy for more than five years.

FURTHER RESOURCES

Books

Henig, Robin Marantz. Pandora's Baby: How the First Test Tube Babies Sparked the Reproductive Revolution. Boston, MA: Houghton-Mifflin Company, 2004.

Web sites

CBS News. "British Couple Has Designer Baby." 〈http://www.cbsnews.com/stories/2003/06/19/tech/main559430.shtml〉 (accessed November 29, 2005).

Health & Medical News. "Test Tube Baby Donor a Parent's Right." 〈http://www.abc.net.au/science/news/health/HealthRepublish_195552.htm〉 (accessed November 29, 2005).

Lifeissues.net. "Lowering the Bar on Test-Tube Babies." http://www.lifeissues.net/news.php?newsID=00013065&topic=〉 (accessed November 29, 2005).

MSNBC Health: Fertility Frontiers, the Future of Babymaking. "'Test-tube' Babies vs. Clones: Human Cloning Should Not Be Viewed in Same Light as IVF." 〈http://msnbc.msn.com/id/3076787/〉 (accessed November 29, 2005).

Reproductive Genetics Institute. "PGD: Preimplantation Genetic Diagnosis." 〈http://www.reproductivegenetics.com/genetics.html〉 (accessed November 29, 2005).

University of Minnesota Cancer Center. "The Nash Family Miracle Baby." 〈http://www.cancer.umn.edu/page/research/trsplant/cord6.html〉 (accessed November 29, 2005).