New "pre-implantation inspection" to be implemented from April next year Expected to reduce miscarriage

Regarding the new technology of "pre-implantation examination" that examines the chromosomes of fertilized eggs and returns those that are not abnormal to the uterus, the Japan Society of Obstetrics and Gynecology said that it is expected to have the effect of reducing miscarriage, from April next year 2 For couples who have had miscarriages more than once, we have decided not to set an age limit and to do it at an accredited facility of the Society.

The Japan Society of Obstetrics and Gynecology held a board meeting on the 11th to discuss a new technique for preimplantation genetic diagnosis called "PGT-A" that examines the chromosomes of fertilized eggs and returns the normal ones to the uterus. rice field.

As a result, from April next year, there will be no age restrictions for couples who do not become pregnant even if they perform in vitro fertilization more than once in a row, or couples who have experienced miscarriage or stillbirth more than once. The policy of conducting the program at the accredited facilities of the academic society, which has more than 100 facilities, was approved.

The reason for deciding to implement it is that the academic society has reached a stage where it is necessary to make rules after conducting clinical research from an adult and reaching a certain conclusion that it can be expected to have an effect of reducing miscarriage.

On the other hand, in vitro fertilization is required to perform the test, and there are risks such as damage to the fertilized egg, and it is not yet clear in the world who the most effective target is. , The target is limited.

"It's not a dream technology for those who want children, but it can be a gospel for those who suffer from miscarriage," said Tadashi Kimura, president of the Japan Society of Obstetrics and Gynecology at a press conference. ..

What is pre-implantation genetic diagnosis "PGT-A"?

According to the Japan Society of Obstetrics and Gynecology, about 15% of cases where pregnancy is confirmed at a medical institution do not lead to childbirth and miscarriage.

Of these, early miscarriage is often caused by chromosomal abnormalities in the fertilized egg, and the rate at which chromosomal abnormalities are found increases as women age.

A new technique for preimplantation genetic diagnosis called "PGT-A" is to collect some of the cells of fertilized eggs that have been fertilized in vitro, examine the chromosomes using a special analyzer, and put the normal ones into the uterus. I will bring it back.

The Society has decided whether there is a difference in the rate of childbirth and the rate of miscarriage by using this technology, couples who do not become pregnant even if they perform in vitro fertilization more than once, and have experienced miscarriage or stillbirth twice. We have conducted clinical research on a total of more than 4,000 couples, including those mentioned above.

While clinical studies have shown a reduction in miscarriage, approximately 60% of cases were unable to return the fertilized egg to the uterus due to chromosomal abnormalities, so the proportion of people who gave birth did not use this technique. There was no difference from the case of in vitro fertilization.

Based on this result, the academic society says that it is possible to avoid the case where the fertilized egg is returned to the uterus even though it seems that it will not lead to childbirth as a merit of using this technology, and it can be expected to have the effect of reducing miscarriage, while domestic and overseas. Many studies have also found no effect on increasing the chances of having a baby.

Furthermore, as a subject of this technology, the society collects a part of cells from the fertilized egg in order to examine the chromosome, so there are cases where the fertilized egg is damaged or a normal fertilized egg is mistakenly diagnosed as abnormal. I mention things that are rare.

Couple who received "PGT-A" "Reduced mental burden"

A couple who participated in a clinical study of an academic society about the new technology of "pre-implantation examination" said that the mental burden of continuing fertility treatment was reduced.

A couple of Mao and Fumitaka in their mid-40s who live in Osaka Prefecture started fertility treatment at a local clinic three years ago when their wife was 41 years old, and became pregnant twice by in vitro fertilization, but twice in a row. I had a miscarriage in the early stages of pregnancy shortly after morning sickness began.

The couple became hesitant to continue fertility treatment due to their mental illness.

After that, when they learned that clinical research on a new technology of "pre-implantation examination" was being conducted, the couple participated in the clinical research from March last year after discussing it.

It is known that the chromosomal abnormality of the fertilized egg increases as the woman ages, and in the case of this couple, the fertilized egg with no chromosomal abnormality was found at the 8th time of the 4th egg collection. It was a fertilized egg.

I transplanted this fertilized egg into the uterus and became pregnant, and in July this year I gave birth to a boy.

Regarding the experience of miscarriage, Mao said, "When I had a miscarriage, I felt that I had a baby in my stomach even for a moment, so when it disappeared, I felt a lot of emptiness and sadness. This painful thing. I was so confused that I should give up my child if I had to do it many times. "

And about the new technology of "pre-implantation examination", "Among the impatience of pregnancy due to age, there is no mental ups and downs due to miscarriage, and it is possible to reduce the mental burden as much as possible and promote infertility treatment. I was able to do it. "

In addition, her husband, Fumitaka, said, "My wife had repeated miscarriages and her body was getting sick, so by choosing a fertilized egg in the test, I think I could have reduced the burden on my wife's body as much as possible." I was there.

Pointing out ethical issues

With the new technology of "pre-implantation inspection", fertilized eggs that are normal and have a high possibility of giving birth are selected and returned to the uterus, but even if there is an abnormality in the number of chromosomes in the fertilized egg, it will lead to childbirth. There is.

In Down's syndrome and trisomy 18, the number of chromosomes is one more, and in Turner syndrome, the number of chromosomes is one less. With the new technology, abnormalities in the chromosomes of fertilized eggs increase the risk of miscarriage. It has been pointed out that there are ethical challenges that lead to the exclusion of these people because they do not return to.

Regarding this technology, Associate Professor Yukiko Saito of Kitasato University, who is familiar with bioethics, said, "Selecting fertilized eggs with chromosomal abnormalities denies that they are born with chromosomal abnormalities, or those who do. There is an ethical issue that can lead to the denial of the diverse society in which we are born. "

Regarding the decision of the Japan Society of Obstetrics and Gynecology, "I think that it is the ideal form of an expert to work closely with the earnest feelings of people who have repeated miscarriages. On the other hand, what kind of ethics should we adopt this technology instead of explaining as if the ethical problem is solved because there is a need for technology and because it exists? , I have a responsibility to explain to both parties and society. "