Filly's 3rd Law
Never trust a fetus to die.
This may sound like a cruel-hearted thing to say. But without doubt, it is the most important lesson I learned as a prenatal diagnostician. This particular law is less important for general obstetrical sonologists than for those who intend to be prenatal diagnosticians.
What is the meaning of this law? It is basically this. You observe a fetus that appears to be either profoundly ill (severe nonimmune hydrops fetalis, for example) or is found to have a severe developmental abnormality (trisomy 13, for example).
You may be thinking… wait, isn’t trisomy 13 always fatal? For good or for bad, trisomy 13 isn't always fatal. We cannot predict how long the baby might live. Babies born with trisomy 13 can survive into their teens.
As a further example, we looked at 27 fetuses exhibiting severe sonographic features of nonimmune hydrops fetalis. 33% survived the neonatal period. We found that on the basis of sonographic features alone neither prognosis nor potential survivors were reliably predicted.
Why do I find this particular law to be so compelling? It is because one may counsel the parents that their fetus will die either in the womb or shortly after birth. It seems a reasonable and rational report to give to them. Then you watch the fetus get sicker and sicker and sicker and sicker! And guess what? The fetus survives and the baby survives but it was terribly damaged as you watched it get progressively more debilitated.
You may have the correct diagnosis and that diagnosis may be very bad, indeed. You may have the experience of fetuses with that diagnosis all dying either in utero or shortly after birth. However, fetuses, like any living creature, want to survive. They haven’t read the paper that convinced you “they will die.” Do not make this mistake.
This may sound like a cruel-hearted thing to say. But without doubt, it is the most important lesson I learned as a prenatal diagnostician. This particular law is less important for general obstetrical sonologists than for those who intend to be prenatal diagnosticians.
What is the meaning of this law? It is basically this. You observe a fetus that appears to be either profoundly ill (severe nonimmune hydrops fetalis, for example) or is found to have a severe developmental abnormality (trisomy 13, for example).
You may be thinking… wait, isn’t trisomy 13 always fatal? For good or for bad, trisomy 13 isn't always fatal. We cannot predict how long the baby might live. Babies born with trisomy 13 can survive into their teens.
As a further example, we looked at 27 fetuses exhibiting severe sonographic features of nonimmune hydrops fetalis. 33% survived the neonatal period. We found that on the basis of sonographic features alone neither prognosis nor potential survivors were reliably predicted.
Why do I find this particular law to be so compelling? It is because one may counsel the parents that their fetus will die either in the womb or shortly after birth. It seems a reasonable and rational report to give to them. Then you watch the fetus get sicker and sicker and sicker and sicker! And guess what? The fetus survives and the baby survives but it was terribly damaged as you watched it get progressively more debilitated.
You may have the correct diagnosis and that diagnosis may be very bad, indeed. You may have the experience of fetuses with that diagnosis all dying either in utero or shortly after birth. However, fetuses, like any living creature, want to survive. They haven’t read the paper that convinced you “they will die.” Do not make this mistake.