The cloning of human embryos is prohibited by law.

The embryos and fetuses of all mammals look quite similar.

If so, then this is all the more true of embryos.

IVF is inefficient so extra embryos are produced in case they are needed.

Freezing unimplanted embryos is now standard procedure freezing unfertilized eggs is under development.

We sell them, we kill them as embryos, we enslave them, we rape them.

Chromosomal abnormalities are found in more than half of embryos miscarried in the first 13 weeks.

It accounts for 26 cases of maternal death in Uganda.Russia with a strict law against abortion found 256 human embryos dumped in a forest of recent,Russian authorities are still investigating the origin of these human embryos.

That belief lay behind Bush s denial of federal government funds for stem cell research that could encourage the destruction of human embryos.

No embryos are capable of suffering, or have hopes or desires for the future that are abruptly cut off by their death.

Prenatal testing of fetuses (or of in vitro embryos before transfer to the uterus) is now well established throughout the developed world.

Perhaps inevitably, our access to human eggs and embryos now enables us to extend prenatal genetic diagnosis to the pre implantation embryo.

IVF is inefficient so extra embryos are produced in case they are needed. These are frozen and many if not most are discarded.

Since 1978, reproductive biologists have helped couples overcome infertility by using increasingly sophisticated techniques for generating and manipulating human embryos in the laboratory.

Does it make any moral sense to say that embryos destined to be destroyed should not be used for life saving stem cell research?

But harvesting stem cells from very early stage embryos that will in the end be discarded is, in my view, ethically distinct from abortion.

Does it make any moral sense to say that embryos destined to be destroyed should not be used for life saving stem cell research?

Most of those who oppose stem cell research do not question its scientific and medical value, but object to the use of human embryos.

But harvesting stem cells from very early stage embryos that will in the end be discarded is, in my view, ethically distinct from abortion.

Stem cells used in this research are best derived from very early stage embryos created by in vitro fertilization, but this leads to ethical dilemmas.

The idea that human embryos could be created with the express purpose of harvesting them for medical purposes incites fear of a brave new world revisited.

But they also want those embryos to be tissue typed in search of a sibling who could serve as a bone marrow donor to their first child.

Most of those who oppose stem cell research do not question its scientific and medical value, but object to the use of human embryos. These critics, especially in Germany, where stem cell research evokes nightmares of Nazi era eugenics, argue that research with stem cells derived from embryos is unnecessary because multi potential stem cells occur naturally in adult tissues as well.

Consider the Korean scientist Hwang Woo suk, whose claim to have extracted stem cells from human embryos that he cloned turned out to be based on phony research.

Understandably, they may want PGD to prevent similar defects in their future children. But they also want those embryos to be tissue typed in search of a sibling who could serve as a bone marrow donor to their first child.

The idea that human embryos could be created with the express purpose of harvesting them for medical purposes incites fear of a brave new world revisited. Even if that extreme is unlikely, the possibility of abuse of any sort generates strong opposition.

Bush, however, cannot rely on that argument, for it is precisely the kind of justification that he rejects when it comes to destroying embryos in order to save, in the long run, those dying from diseases for which we currently have no cure.

For example, intracytoplasmic sperm injection is a technique in which a single viable sperm is injected into an egg, allowing fertilization to occur even in cases where few healthy sperm are available. Freezing unimplanted embryos is now standard procedure freezing unfertilized eggs is under development.

Surgically harvesting eggs from a woman's ovaries, fertilizing them outside her body, and transferring the resulting embryos into her uterus enabled effective treatment of female infertility caused by irreparably damaged fallopian tubes. Since then, rapid innovation has led to new applications for IVF and other assisted reproductive technologies.

Since 1978, reproductive biologists have helped couples overcome infertility by using increasingly sophisticated techniques for generating and manipulating human embryos in the laboratory. At the same time, molecular biologists have been working to overcome human disease by deciphering the entire sequence of the human genome and constructing tools to correct genetic and cellular defects.