IN VITRO FERTILIZATION: GIFT OF THE GODS OR PANDORA'S BOX
Rapid developments in reproductive technologies compel science teachers to introduce their high school students to techniques which show great promise and yet hold many ethical dilemmas.
Intended Audience: Mature high school students in biology, health, and STS (Science, Technology and Society) classes
Case study: In Vitro Fertilization
1 copy per student-"Making Babies," Time, September 30, 1991. (optional-excellent for higher level students)
Video, "Hi-tech Babies," NOVA, (1st 30 min-IVF; 2nd half addresses surrogacy) (optional, but excellent)
In Vitro Fertilization
CASE STUDY 1:
Betty and Junior Davis were married in 1980. After trying for six years to have a child, they went to an infertility clinic. Previous damage to Betty's Fallopian tubes made her a candidate for Zygote in vitro fertilization transfer (ZIFT), a form of in vitro fertilization where Joe's sperm were mixed with about 4-8 of Betty's eggs and fertilized in a Petri dish. 4 of the pre- embryos were returned to Betty's lower Fallopian tubes in hope that the pre- embryo would implant in the uterus - the start of pregnancy. The remaining zygotes now called "pre-embryos" are frozen at -90�C for additional IVF procedures if needed.
No pregnancy resulted and subsequently the Davises decided to divorce. Betty requested the custody of the extra fertilized pre-embryo stage cells which had been frozen to use at a later date. Mr. Davis insisted that the infertility clinic not release the embryos as he no longer wished to become a parent. Since no laws have been developed regarding the dispersal of pre- embryos in the event of divorce or death of genetic parent, the case went to the courts for settlement.
Your role will be to act as a panel of judges to settle the dispute.
In 1978 Louise Brown was born in England, the first test tube baby ever. Since then over 10,000 babies have been born using the technique of " in vitro fertilization." Some of the fertilized eggs (now called pre- embryos) are transferred to the woman's Fallopian tubes for the trip to the uterus, where pregnancy will start if the fertilized egg successfully implants in the uterine wall about 14 days after conception. Usually four to eight eggs are harvested from the ovary. Only two to four eggs of the fertilized eggs are returned to the woman's body. The remaining embryos are frozen (quickly at -90�C) for future IVF procedure in case the first one doesn't result in a pregnancy. Pregnancy occurs if the pre-embryo implants in the uterus which then begins the production of those hormones which will direct and support the development and sustenance of the embryo by the development of the placenta, umbilical cord, etc. system which connects the mother's blood stream to the embryo's. Only when that implantation and hormone production begin is the woman pregnant. (It is the hormone human chorionic gonadotropin which the new home pregnancy tests are detecting.) Also it is only on implantation that differentiation begins and only then can one technically call the cell mass an embryo. Only about 1/4 of the procedures result in a pregnancy which goes to full term with the delivery of a healthy baby. Incidentally, scientific evidence indicates that in normal situations only 1/3 to 2/3 of all fertilized eggs ever succeed in implanting.
(High school students don't particularly like teacher-picked groups. Self-selecting groups tend to lack significant diversity of ideas and easily get off task because of social dynamics. Having students draw playing cards from a deck as they come to class works well. For this particular activity, use as many suits as there will be groups and as many number values as numbers of students that will be in the group. So in a class of 24 students, the deck would hold all four suits with cards from the ace to the six. If you have 27 students, then use the "7s" from three of the suits. For many group activities, three to four students work best. So have all the " threes" be a group and so on.)
Berlfein, Judy. "Earliest Warning," Discover, Feb., 1992 p.14.
Conkling, Winfred. "From Fertility to Fatherhood", American Health p. 10-11.
Elmer-Dewitt, Philip. "Making Babies", Time, Sept, 30, 1991, pp. 56-63.
Hall, Elizabeth. "When Does Life Begin", Psychology Today , Sept. 89.
Hopkins, Ellen. "Tales from the Baby Factory", New York Times Magazine, Mar. 24, 1992, pp.38 ff.
Ozar, David. "The Case Against Thawing Unused Frozen Embryos", Hastings Center Report, Aug. '85, pp.-12.
Robertson, John A., "Resolving Disputes over Frozen Embryos", Hastings Center Report, No/Dec. 1989.
Sanders, Alain, "Whose Lives are These:?" Time Oct. 2, 1989, p. 19.
Singer, Peter, "Making Laws on Making Babies", Hastings Center Report, pp.-6.