In vitro fertilization has advantages over natural conception for couples who both carry the cystic fibrosis trait
Research Activities, March 2011, No. 367
For a couple who are both carriers of the gene for cystic fibrosis (CF) and want to have a healthy child, in vitro fertilization (IVF) combined with preimplantation genetic diagnosis (PGD) has advantages over natural conception and prenatal testing, a new study finds. Cystic fibrosis is a chronic, progressive illness that primarily affects the respiratory and digestive systems and is caused by a recessive mutation in a single gene. Children with two copies of the CF allele have an average life expectancy of 37 years, so genetic screening for CF is now offered to all couples actively planning to have children.
The researchers compared expected lifetime income less expected lifetime medical expenses for offspring of a two-carrier couple who used IVF and PGD to prevent having a child with CF, versus a similar couple who used natural conception and prenatal diagnosis. The result was a substantial net economic benefit for IVF/PGD users, depending on the mother's age. The net benefit was calculated to be highest ($182,000) among couples in which the woman was younger than 35 years, somewhat lower ($114,000) if the woman was between 35 and 40 years. This approach had a negative net benefit (-$148,000) when the woman was older than 40, when conception/prenatal diagnosis was favored. Using IVF and PGD, affected embryos can be discarded before implantation, while a couple using natural conception and prenatal testing would face terminating a pregnancy.
Because of the cost of IVF, couples are likely to switch to natural conception after about five attempts in vitro, the researchers noted. To perform the cost-benefit analysis, they took the best available information for their model. This included rates of conception (by age of mother), rates of termination of pregnancy by mothers with CF fetuses, costs of medical care for IVF/PGD or prenatal diagnosis, average lifetime costs of medical care for normal and CF individuals, and average lifetime income for normal and CF individuals. The study was funded in part by the Agency for Healthcare Research and Quality (T32 HS00028).
More details are in "A cost–benefit analysis of preimplantation genetic diagnosis for carrier couples of cystic fibrosis" by Lynn B. Davis, M.D., M.S., Sara J. Champion, M.S., Steve O. Fair, M.B.A., and others in Fertility and Sterility 93(6); pp. 1793-1804, 2010.