PRE-IMPLANTATION GENETIC DIAGNOSIS: HALACHIC PERSPECTIVES--
Most people have a natural desire to bear healthy children, both in body and in mind, and want to prevent the birth of children with severe diseases or handicaps. There are various means to achieve these goals, some legitimate and some highly controversial. For many years, the most acceptable means has been the prevention of marriages between couples who are at high risk of passing on genetic diseases to their offspring, whether discovered through family histories or through genetic examinations before their marriage.
The “Dor Yesharim” organization has done wonderful work in this area. Most people have a natural desire to bear healthy children, both in body and in mind, and want to prevent the birth of children with severe diseases or handicaps. There are various means to achieve these goals, some legitimate and some highly controversial. For many years, the most acceptable means has been the prevention of marriages between couples who are at high risk of passing on genetic diseases to their offspring, whether discovered through family histories or through genetic examinations before their marriage. The “Dor Yesharim” organization has done wonderful work in this area.
Pre-natal diagnosis of diseases and handicaps during pregnancy is far more controversial. Medically, it is possible to diagnose various diseases and handicaps during pregnancy by using fetal ultrasounds, placental villi sampling, amniocentesis and by checking various indicators in the mother’s blood. Medical literature talks of hundreds of abnormalities that can be diagnosed in the fetus before birth.
All these tests assume a decision can be made to abort the fetus at various stages of the pregnancy, so there is controversy about their legitimacy. Some claim that the status of a damaged fetus is essentially different from the status of a healthy fetus and of a handicapped newborn. Therefore, according to this viewpoint, it is permitted to abort an unhealthy fetus, even though it is forbidden to abort a healthy fetus or to murder a handicapped newborn. This is the position of Israeli law and a minority of poskim (halachic judges) agree.
However, most poskim forbid abortion, if it is indicated only due to a health problem of the fetus, and some of them view an abortion of this kind as murder. In their opinion there is no essential difference between killing a handicapped child before or after his birth (although there would be different punishments in each case) -- the right to life is a basic halachic right beginning from the 40th day after conception.
Recently a new method has been developed to prevent the birth of children with severe diseases and handicaps. It is known as PGD, or pre-implantation genetic diagnosis. These are diagnostic tests performed on individual cells taken from fertilized eggs outside of the body. The tests are done at the very first stages of division of the newly-fertilized egg.
The goal of this method is to remove the fertilized eggs which are affected by disease or defect, and to implant within the woman only those fertilized eggs which are healthy.
Using modern methods of molecular biology, it is possible to directly check the DNA of a single cell and detect chromosomal disturbances, enzyme deficiencies and metabolic disturbances. One can check genetic problems from the mother’s side already at the stage of the single egg, even before it is fertilized, by checking the polar body of the egg. It is even possible to check genetic disturbances in the fertilized egg immediately after fertilization or during the first days after only a few divisions of the cell. This method can detect dozens of genetic diseases.
Most contemporary poskim hold that abortion is considered murder only when the fetus is inside the mother’s womb. This is not the case when the pre-fetus is outside of the womb, and therefore there is no prohibition regarding the destruction of eggs fertilized before implantation. According to the halachic perspective, the fetus acquires “rights” gradually, proportionate to his biological development. These rights increase until he exits his mother’s womb. From this point on, his destroyer would be considered a murderer, and liable to the death penalty, even if the newborn is only a day old. The development begins with the sperm cell, through the fertilized egg prior to implantation, through the implanted fertilized egg up the 40-day point, and finally the fetus developing from 40 days on (with various interim dates with no halachic significance).
Furthermore, according to halacha, there is a pronounced distinction between the pre-fetus and the fetus, with the transition point being the implantation in the womb.
We can adduce proofs for this approach from the source for prohibition of abortion, where the verse says “he who spills the blood of man in man, his own blood shall be shed.” (Genesis ch.15).The Talmud (Tractate Sanhedrin 57B) comments: “Who is the man in the man? This is the fetus in his mother’s womb".
From this verse the poskim conclude that the definition of a person begins only after he is inside his mother’s womb. Therefore, a pre-fetus outside of the womb is not considered a person, and destroying this would not be considered murder. For the same reason it is permitted to destroy frozen fertilized eggs when a couple divorces or when the woman dies.
It is thus permitted to perform diagnostic tests on the fertilized egg before implantation in order to identify severe handicaps, in which case the egg may be destroyed. This was the decision of Rabbi Rabbi Yosef Shalom Elyashiv in relation to a case of neurofibromatosis, and Shaare Zedek’s poskim, Rabbi Moshe Halbershtam and Rabbi Yehoshua Neuwirth, shared this position when they approved the establishment of a unit for pre-implantation genetic diagnosis within the Jozef Natansohn IVF Unit.
Thus we see that, in the case of a couple carrying a severe genetic disease, they are permitted to use the PGD technique, wherein the egg is fertilized outside of the body, the fertilized eggs are tested, and only healthy ones are selected for implantation.