Anna and Brian took a common genetic test to determine the condition of the embryos they had created. All 13 were abnormal.

They had a healthy daughter after three years after using an embryo that they had decided not to test.

They went to a new clinic that questioned the reliability of the popular genetic test they took. Two of the couple's irregular embryos were implanted by the clinic, one with one chromosomal error and the other with two errors. A baby boy was born last month.

I became pregnant with him when I was 46. That is a long time and a lot of valuable years in my child's upbringing and my life.

Preimplantation genetic testing for aneuploidy has become a standard add-on to I.V.F. procedures over the last two decades. The test, which can cost anywhere from $4,000 to $10,000, has become controversial as studies have cast doubt on whether it increases birthrates from I.V.F. A growing number of scientists are questioning the widespread use of the test, which leads to tens of thousands of discarded embryos per year and causes many women to believe they may not be able to carry a biological child.

50 patients underwent transfers of abnormal embryos at the Center for Human Reproduction in New York City, according to a new study. The local clinic wouldn't implant the abnormal embryos, so they were transferred to this clinic. There have been eight births after 57 transfer cycles of embryos with abnormal genetic testing results. Seven of the babies were healthy. The average age of the women was 41 years old.

The center first showed that selected abnormal embryos could still be viable in a study in 2015. Other fertility clinics have begun to transfer such embryos.

The research was funded by the Foundation for Reproductive Medicine, a nonprofit organization based in New York.

The director of research at the Hastings Center who was not involved in the research said that the new study supports concerns about the accuracy of the tests.

The limitations of transferring such embryos are shown in the new study. The transfers led to 11 miscarriages and eight live births, but the majority of the embryos had only one or two chromosomal abnormality.

Laura Hercher is the director of student research at the Sarah Lawrence College genetic counseling program.

Aneuploidy is when the number of chromosomes in a sample is too few or too many. Down syndrome can be caused by an abnormal number of chromosomes. The wrong number of chromosomes can lead to failed pregnancies, either by preventing embryos from implanting or by causing miscarriages.

The authors of the study argue that the problem with PGT-A is that it provides an incomplete picture that is often interpreted as a very definitive result. The test uses a small sample of cells from the outer shell of the embryo to see if there are 23 pairs of chromosomes.

The goal of the study was to find embryos that would give someone a better chance of getting pregnant.

The authors of the new study argue that viable embryos are being ignored, leaving many women to believe they have no other options than to have a baby.

Dr. Gleicher, director of the clinic and a co-author of the study, said by email that the miscarriage rate is roughly what one expects at such advanced age. Ask women what they like. There is a chance of a baby not being born. The answer will be clear.

The fetus was diagnosed with a heart defect in one of the pregnancies. The parents had a live birth. The baby that had surgery as a newborn is doing well. There was no known connection between the birth defect and the chromosomal error, according to Dr. Gleicher.

There is a risk of birth defects if there is a bigger study of outcomes. This outcome speaks to the level of uncertainty that fertility providers will have to face when it comes to the potential risks involved with using these embryos.

We don't know what to tell them about the long term consequences of a child that is born. Will they have problems down the road? There is a lot of that.

As women get older, the number of chromosomes that are irregular is more common. The incidence of aneuploidy in embryos produced during I.V.F. increases with age, for women over 35. Errors that occur down the line can be replicated as the fertilized egg divides into cells. The normal cells might have a competitive advantage over the abnormal cells, leading the majority of the cells in the embryo to have the correct number of chromosomes. Some of the incorrect cells may eventually self-correct.

Any one picture of the embryo will be limited because of the patchwork of cells. One cell with the wrong number of chromosomes can turn up abnormal results if a normal test result misses irregular cells elsewhere. Some fertility clinics may be hesitant to accept embryos that could lead to healthy pregnancies because of the risks associated with sampling just a small subset of cells at a very early stage in embryo development.

Women who don't undergo I.V.F are at risk of getting false positives.

Some researchers think that some people still benefit from the use of PGT-A. Younger patients who produce more eggs can use the test to find out which embryos have the best chance of succeeding.

The first two cycles of I.V.F. could not be used because the embryos they produced were abnormal.

She felt powerless because the fertility clinic wouldn't allow potentially viable embryos to be used and they had to wait six years to use them. Few clinics will agree to transfer such embryos, and the couple didn't know that at the time they took the test.

She said that she felt like it was unfair.