The potential and actual applications of reproductive technologies have bee
n reviewed by many governmental committees, and laws have been enacted in s
everal countries to accommodate, limit and regulate their use. Regulatory s
ystems have nevertheless left some legal and ethical issues unresolved, and
have caused other issues to arise. Issues that regulatory systems leave un
resolved, or that systems have created, include disposal of embryos that re
main after patients' treatments are concluded, and multiple implantation an
d pregnancy. This may result in risks to maternal, embryonic and neonatal l
ife and health, and the contentious relief that may be achieved by selectiv
e reduction of multiple pregnancies. A further concern arises when clinics
must (or choose to) publicize their success rates, and they compete for fav
orable statistics by questionable patient selection criteria and treatment
priorities. (C) 1999 International Federation of Gynecology and Obstetrics.