They risk failure, miscarriage and often multiple births.
Infertile couples sometimes spend tens of thousands of dollars on IVF procedures, one after another, until one succeeds in pregnancy.
Sometimes none do, or a miscarriage results.
Now a new technique is making headlines around the world.
Called NGS IVF, it may be a more efficient way to pregnancy.
One couple in Philadelphia is an example.
MaryBeth Scheidts and David Levy brought baby Connor into the world, and with him, brought to the world's attention a new method of IVF that helps find the best embryo to implant in a woman's uterus.
"You improve the efficiency of IVF, you decrease the miscarriage rate and you can avoid diseased babies," said Dr. Jamie Grifo of NYU Langone Medical Center.
In standard IVF, mixing a woman's eggs and a man's sperm may produce embryos that look perfectly normal under the microscope, but which actually have too many or too fe chromosomes or which may carry disease genes.
"Many embryos made in bed or in the lab are chromosomally abnormal and not able to make a baby," said Dr. Grifo. "Some of them make a pregnancy but the preg miscarries because it's chromosomally abnormal."
The new method called NGS dramatically drops that miscarriage rate.
Doctors let the embryos develop awhile, then take a few early placenta cells.
They check them for a normal chromosome count and the absence of disease genes.
Implanting that embryo greatly increases the chance of a healthy pregnancy.
This method may be particularly useful for older women.
The older a woman gets, the more likely it is for her to have embryos with an abnormal number of chromosomes.
Using NGS to find one that's normal means implanting only that one.
It avoids multiple births from implanting multiple embryos and may reduce the risk of a D and C after a miscarriage.
It may reduce the cost of multiple IVF's in an attempt to conceive.
"I think the day will come and it's very soon, when we will screen embryos in everybody, because the reason that IVF fails is that embroys that look good aren't and this allows us to find the ones that are good," said Dr. Grifo. Each IVF attempt may cost as much as $10,000 to $20,000.
Some of the genetic diseases that can be found using the NGS method include Tay-Sachs, Gaucher's and cystic fibrosis.
Dr. Grifo says the technique is ready to be used right now, and is awaiting New York State approval.