AFS Cells: A Non-controversial source of pluripotent cells?

There is a new report out today that suggests there is a new, non-controversial and "ethically sound" source of pluripotent stem cells: amniotic-fluid stem cells, which, as the name indicates, are stem cells found free-floating in the amniotic fluid. They are also apparently present in the placenta.

According to Dr. Anthony Atala, the specialist at Wake Forest University who led the research team, these cells are neither embryonic stem cells nor are they adult stem cells. They're something in between, fully flexible like embryonic stem cells, but non-controversial. And this is where I take issue. Dr. Atala is saying, and I quote from the above article,

the amniotic cells can be taken easily and harmlessly from the placenta or from pregnant women by amniocentesis

while David Prentice, a senior fellow in life sciences at the Family Research Council, (who strongly oppose embryonic stem cells) says that the AFS cells come with "little ethical baggage". But anyone who's been through amniocentesis knows that there is actually a risk of miscarriage with every insertion of a needle into the womb; according to the CDC, it's a risk of one in 200 to one in 400 women will miscarry, depending on the skill of the person performing the procedure.

This is not harmless. This is not easy. This is not little ethical baggage. If it's so bad, so wrong, to create embyronic stem cells because of the loss of potential life, how can anyone justify the potential miscarriage of a developing, in utero fetus?