By Elaine Cassel
For men and women whose opportunities to become parents are limited by health or genetic problems, assisted reproductive technologies (ART) offer an alternative to childlessness or adoption. But recent studies indicate that children conceived through these methods face multiple risks.
Several methods are used to assist couples in conceiving children. These include:
- artificial insemination, in which sperm from a donor is artificially introduced into a woman during ovulation;
- egg donation, in which eggs are harvested from a donor, fertilized with sperm, and inserted into the birth motherís uterus;
- gamete intrafallopian transfer (GIFT), in which both sperm and egg are inserted into the Fallopian tube of the birth mother where fertilization occurs; and
- zygote intrafallopian transfer (ZIFT), similar to GIFT except that fertilization occurs in vitro (in the laboratory) and, after cell division, selected embryos are inserted into the Fallopian tube.
Recent research focused on the effects on the child of two other methods-- in vitro fertilization (IVF) and intracytoplasmic sperm injection. IVF involves the harvesting of eggs from the genetic mother, fertilizing the eggs with as many as 100,000 sperm from the genetic father, and, after cell division, transferring embryos into the birth motherís uterus. IVF is used when the genetic mother suffers from Fallopian tube blockage, or occlusion. Itracytoplasmic sperm injection, recommended with the fatherís sperm count is very low, involves aspirating sperm from the male and, in vitro, inserting a single sperm into each egg harvested from the genetic mother. As with IVF, the resulting embryos are screened and a number of healthy ones placed into the Fallopian tube of the birth mother.
A study published in the March 7, 2002 New England Journal of Medicine
found that infants conceived by these methods have a higher risk of birth defects than infants conceived naturally. Researchers assessed data on natural births, births after assisted conception, and major birth defects in infants (diagnosed by one year of age) born between 1993 and 1997 in Western Australia. Nine percent of infants conceived with in vitro fertilization and 8.6 percent of infants conceived by means of intracytoplasmic sperm injection manifest at least one major birth defect by one year of age, more than double the rate found in the population of naturally conceived infants; they were more likely than naturally conceived infants to have multiple major defects, including chromosomal and musculoskeletal abnormalities.
A study of IVF births published in the British Journal The Lancet
on February 9, 2002 made similar findings. Researchers examined records of normal and IVF conceptions reported in Swedenís birth registry from 1982 to 1995 and cross-referenced those entries with records from the countryís 26 childhood disability centers that provide the medical, social, educational, and psychological care for all Swedish children born with neurological impairments. Compared with babies conceived naturally, IVF babies were twice as likely to be treated for neurological impairments and almost four times more likely to be diagnosed with cerebral palsy and severe developmental delays.
ART procedures are also related to low birth weight babies. The Centers for Disease Control and Prevention looked at 42,000 ART babies born in the United States in 1996 and 1997. They found that ART pregnancies accounted for 3 percent of low birth weight babies (those weighing less than five and one-half pounds) and 4 percent of very low birth weight babies (weighing between two and three pounds). Low birth weight increases a babyís risk of mental retardation threefold and very low birth weight infants are 30 times more likely to have severe retardation or cerebral palsy than normal weight infants.
What all of these studies fail to reveal is how much of the risk factor is related to the procedures themselves and how much is attributable to the multiple births occasioned by the implantation of several embryos in an effort to insure one live birth. (The CDC study found that even when accounting for multiple births that lead to early delivery, ART babies were twice as likely to have low birth weight than that found in the general population.)
This research raises serious questions about the use of these procedures. More than 82,000 ART procedures were performed in the United States in 1998 (resulting in 29,000 births), the most recent year for which full statistics are available. That was a 12 percent increase over 1997. More than 50,000 births worldwide are attributable to ART procedures. IVF, intracytoplasmic sperm injection, ZIFT, and GIFT are exploding in popularity. Insurers are agreeing to pay for more ART-related costs, as infertility is considered to be a major life disability under the Americans with Disabilities Act, which prohibits discrimination in medical care and coverage.
While more data is being accumulated, prospective parents need to be aware of and weigh the risks when making decisions about whether or not to undertake these procedures.
Hansen, M., Kurinczuk, J., Bower, C., & Webb, S. (2002, March 7). The Risk of Major Birth Defects after Intracytoplasmic Sperm Injection and in Vitro Fertilization. New England Journal of Medicine, 346
Retrieved March 7, 2002 from http://content.nejm.org/cgi/content/abstract/346/10/725
Brown, D. (2002, March 7). Studies: Test-Tube Babies Face Higher Health Risks. The Washington Post
, p. A5.
Elaine Cassel, Marymount University and Lord Fairfax Community College