TRAP syndrome in pregnancy

I know someone who is pregnant with twins who are affected by what is called a TRAP sequence (twin reverse arterial perfusion sequence). It is a very rare condition in which one twin never develops a heart or head and basically acts as a parasite on the other twin. The other twin (known as a “pump twin”) pumps blood to the twin without a heart, keeping it alive. Because the pump twin is doing all the work to pump blood between the both of them, there is a huge risk of death for both twins because it is too much strain on the one heart. “Selective fetocide” is being advised, which means taking the life of the baby without a heart in order for the pump twin to be able to live. The twin has no heart or brain and would not be able to live except that it is feeding off of the normally developing baby. Even if both babies make it through the whole pregnancy, the twin without a heart will definitely die once the blood supply is cut off at the time of birth. Does the principle of double effect come into play here? The killing of the baby is going to result whether its blood supply is cut off in utero or after birth. This is a terribly sad situation for the mom :frowning: Please pray for her and the babies. She was actually pregnant with quadruplets–two singletons and two in the same sac. One of the singletons already died, so now there is just the one singleton and the two who would have been identical (the TRAP twins). The amazing thing is that this woman was not trying to get pregnant. Most people think of fertility drugs being a factor in these multiple pregnancies, but she wasn’t using them. She had just been diagnosed with cancer and had previously been told that she was completely infertile–that it would never happen. It is still turning out very sad, but on the positive side there are two babies in there who still have a chance and God is not done with her yet! Please pray for her!!!

The principle of double effect does not allow for “selective fetocide”. The principle of double effect allows for bad effects, unintended and in proportion to good effects, but does not allow for bad means (eg killing one baby) to achieve the good ends.


Separating the fetuses would presumably be morally neutral and the death of the acardiac twin an unintended but allowable bad effect.

Is a acardiac twin that has no brain or heart considered a person? I would contact the National Catholic Bioethics Center (link below) to discuss this difficult situation. If it’s not a person, then the situation may morally allow for an easier medical approach.

Can the twins be seperated in utero anyway?

Well, it’s not really a separation of the two babies from one another… They are not connected to one another except through the placenta. Basically the non-viable (acardiac) twin would have its blood supply from the placenta cut off with a coagulation device, thus allowing the pump twin to be able to keep its own blood supply and develop normally without cardiac failure. The unfortunate effect of this would be that the acardiac twin would die. This is exactly how the acardiac twin would die at the time of birth if he/she made it that far, which is why I was thinking this would be permissible… Because, as I understand it, the severing of the attachment to the other baby’s blood supply will eventually lead to death for the acardiac twin in either circumstance. It is just a matter of whether or not to do it at the time of delivery and compromise the other baby or to do it earlier and give the other baby a chance. That was my thinking on it. Is this correct?

That’s above my pay grade, sorry rissa. The NCBC would be best able to address this.

I doubt that cutting off a blood supply from the placenta to a fetus could be considered an acceptable (morally neutral) means of achieving this. It is killing one to save the other.

I’d be more inclined to think that the acardiac twin is not treated as a person (no heart, no brain) and so the morality of the operation is completely different, but you’d want to address this with the NCBC. The case of anencephalic infants (they have hearts, but severely underdeveloped brains) has been considered and they are treated as persons by the Church. But I don’t know how these such cases would relate.

As I’ve mentioned before, I’m a women’s health nurse practitioner. This poor mother deserves our prayers–what an awful thing to happen. An acardiac twin is much like an anencephalic baby (one born with no brain at all–they look very strange when born–kind of like a frog as they have no skull in back even). There is NO possibility for life in either of these cases, and death always occurs within a short time after birth, if not before. Most of these pregnancies will be terminated when found to be such–and most people would look at it as the same as a blighted ovum–ie not a real pregnancy. A very reasonable argument can be made that the fetus is not even actually human–as it lacks the ability to think and feel, They lack a brain stem so they cannot regulate their heart rate after birth–and in this case where the parasitic twin doesn’t even have a heart-- there isn’t even something to regulate! I don’t mean to sound crude, but in the pregnancy described, the parasitic twin is basically a mass of tissue–an extra set of arms and legs and trunk–and not a baby at all. It’s more like a baby born with a 3rd leg growing out of its side–the answer of course would be to remove the extra leg. Do you see my point? The only reason that I have ever heard of someone continuing the pregnancy once something like this is discovered, is if the organs were to be harvested–ie if the kidneys were good for instance.

If the mother described above continues this pregnancy, she will most likely lose the twin who is normal—and quite possibly both babies in utero. The healthy twin will almost assuredly die soon from heart failure, and the singleton other baby will probably follow suit due to the trauma of the death process going on with the twin pregnancy. God has blessed this mother with 2 healthy babies. She should go for the selected reduction–and count her blessings for the 2 babies she will receive from God!

The Church teaches that we are to consider a life human from the first moment of conception-- including embryos (who also have no brains or hearts yet). Whether we have a heart or brain we are still a human being.

I concur with calling the NCBC.

So sad that life has become devalued so.

That is not what makes us human. That is not a “reasonable” argument. That is an abominable argument, certainly not a Catholic one.

Even worse, now we propose to harvest organs from a living person.

‘selective reduction’ = abortion = always evil

My thought in the whole thing was the fact that when the baby might be born, it would still die of having its blood supply cut off at that time because the removal of the baby from the womb would sever its connection to the other twin who is pumping the blood. It is already established that the baby will not develop to the point where it would ever have the capacity to do this on its own. So the cutting off of the blood supply earlier in pregnancy simply does the exact same thing as what will inevitably be done later in pregnancy by nature of the fact that the baby cannot remain in utero. The only difference would be in the timing of doing this. Earlier to save the other baby vs. waiting until later and possibly not being able to save the other baby, but still having to cut off the blood supply nonetheless. Maybe I am not explaining that very well. I am not sure…

To the person who said that it is a person at conception, I would agree 100%. But the thing that comes into play in this situation is the fact that this is a monochorionic pregnancy–meaning the twins should have been identical. They are in the same sac. The way identical twins are conceived is different from how fraternal twins are conceived. They come from the uniting of one egg and sperm and then somewhere along the line the cells/DNA splits into two separate babies. But they do not start as two separate conceptions, as is the case with fraternal twins. So in the case of the twins where the cells split and one does not develop a heart or a brain, which is needed for our intellect and free will, it is easy to see how that could be viewed as more of a cellular deformity of extra appendages rather than as a newly ensouled human being. This also raises all sorts of questions in my mind about when identical twins become separately ensouled from one another. Does God create two souls at the moment of conception, knowing that they will be twins, or does the second baby somehow become ensouled at the point that it begins to develop into a twin pregnancy?

I do not claim to know any of the answers to these things, but they are questions that have been going through my mind ever since I began to ponder this situation.

We all die.

The issue is whether or not it is permissible to kill others-- it is not.

Intellect and will are the principles of the soul, not the body. If the body is deformed, the soul may not be able to express itself at all, or fully, but our soul exists.

We must presume that each is ensouled we need not know when or how.

I know. That question was more my curiosity of when or how. It was me thinking out loud. I am a very analytical person :wink: Ultimately, it does not matter. But I am just a curious one lol

I am not so sure I agree with you on the ensoulment without hope of ever developing brain or heart though. I also do not disagree. I just am not sure on the matter. Because I have always been told that the capacity for intellect and free will are what makes us unique and ensouled beings. I have been told by priests that animals are not ensouled, and the rationale/evidence for this is that they have no intellect or free will in the same manner that a human person does. The ability to reason has always been described as a key factor in the matter. I understand the argument that some children/people do not have the ability to express intellect and free will due to a problem with their health. But they still have the faculties for that intellect and free will, although they are not functional in a manner that is obvious by observation. However, in the case of a pregnancy where there is no heart or brain ever developed and never will be developed, the capacity does not exist for intellect or a free will. Again, I am neither agreeing nor disagreeing. I simply do not know. This one is beyond my comprehension.

Yes, this is true. Intellect and will are the two operations of the spiritual soul.

It’s the other way around. because they have no spiritual soul, they have no intellect and will. They have material souls.

It’s not a good argument because it’s backwards. We are able to reason because we have a soul. Demonstrating reasoning does not equate to a soul. A monkey can learn to flip a switch, it does not follow that this demostration proves they have a spiritual soul.

If we have a soul, we de facto have intellect and will. Intellect and will are principles of spiritual beings-- angels for example, and us. Humans have both, spiritual soul and material body. Angels have only spiritual soul, no material body. When our soul leaves the body, the intellect and will remain-- it is what it means to be eternal. It is what it means to be human. Our spiritual soul will be united with a perfect glorified body. The defects of our human body in this world do not determine the existence of our soul.

The capacity for intellect and will does not reside in the heart or the brain. It resides in the soul, which is immaterial.

I can recommend Theology for Beginners by Frank Sheed to help with the principles of the soul.

So if they were both born, would it be moral to cut the tube connecting them or would the living twin have to live with a parasitic twin their whole life?

I’d argure that the parasitic twin may not have a soul since it’s not able to live with out the pump twin. The soul is the principle of life, where there’s no life there’s no soul.

This brings a major question to my head. This case sounds to me very similar as the case of the Salvadorian woman pregnant with the baby that had no brain, who was denied an abortion but instead had a C-section with the ultimate end of killing the baby earlier. I remember questioning the morality of this situation and the unanimous response I got was that the c-section was morally licit basically because the baby had no brain, had no chance to live and was going to die anyway at birth (and the only thing the pregnancy would do was putting the mother’s life at risk). This situation is quite the same thing, so then does that mean that in the case of the Salvadorian woman the c-section was not permissible? And here to, accelerating what iS going to happen at birth to save the other baby’s life is not permissible? I am quite confused because I was told by every single person that basically accelerating what is Going to happen at birth anyway to save the other is morally licit.

The placenta and umbilical cord cease witih birth. So, the natural result is death of one child. If they are able to be separated in utero, that is also acceptable. They are not conjoined twins, a different matter entirely.

You have it backwards.

Direct abortion is always wrong. There may be other procedures that untintentionally result in the death of the child, but are not the intended action, which can be tolerated under double effect.

I am not familiar with the other situation you describe, but if the direct intention and action was to kill the child it is not morally permissible.

No it isn’t merely accelerating what happens at birth. Currently both babies are attached to the placenta, after birth the healthy child is detached from the placenta, which it no longer needs to be attached to, via cutting of the umbilical cord. Then the placenta stops functioning and the unhealthy twin, which still needs an external blood supply/pump, will die.

That is as different to prematurely and artificially cutting off that supply as night and day. What is being proposed is like saying to a mother whose child is dying naturally of malnutrition “oh well, might as well not bother feeding it any more, it’ll eventually die anyway, just starve it now and kill it off quickly”.

Yes the situation I mentioned the intent was to “terminate the pregnancy” the mother didn’t want the child and in fact she wanted an abortion. She couldn’t do it because it is illegal in her country, so because they were not able to.kill the baby Via abortion she and her doctors went with performing with a c-section (I don’t remember exactly but I think it was at 26 weeks) because the baby was not going to survive. The mother was not in any distress and her pregnancy had developed so far with no health issue (she had lupus and there was a question of maybe some health issue arising in the future but at the moment of the c-section nothing) so as the intent in this case was to kill the child then it was not permissible (good aclaration as again there were quite a few saying that was permissible).

Now, going back to the present threath, if there was a way to separate or cut the tube that goes (I guess, I am not a doctor) from the twin with no heart and brain in utero to save the other twin, and the twin with no brain dies as a result of the attempted separation, is that what would be permissible in this case??

So this was an end-run around the abortion laws of that country, but an abortion all the same. Intrinsically evil.

Yes, if the intent was to separate the two twins from each other, I would think that would be moral.

There is no “tube” going between the two children. There are two umbilical cords both attached to the placenta. I do not think it would be moral to simply cut the umbilical cord of the one twin.

While there may not be an actual ‘tube’ going between the two, I feel that this doesn’t really explain the situation. In TRAP syndrome, there is an abnormal communication between the blood vessels in the placenta, it’s not just that the two are sharing a placenta. I believe that this abnormal communication also occurs in twin to twin transfusion syndrome (TTTS).

The procedure that may be considered in TRAP syndrome does not involve cutting the umbilical cord of the trap twin, it is coagulating or ablating the abnormal connections between the umbilical cords, which in effect separates the twins from each other.

In TRAP syndrome, the trap twin has no head, no brain, no arms, no heart, although legs may be present. It’s difficult to see how the trap twin could truly be considered a person as there is no brain and no heart. It’s not that these are abnormal in some way, it’s that they are not present at all.

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