December 10, 2010

Claire M. Tempany-Afdhal MD
Boston, MA

Dear Dr. Tempany-Afdahl,
I was much interested in you lecture at the RSNA last week.  I shall be bold enough to write this about a matter of great importance relevant to what you said.  I hope you will be kind enough to bear with me.

I am of course a diagnostic radiologist.  In the past I used to do hysterosalpingograms for infertility.  The majority of the studies were normal.  This was frustrating.  As a radiologist my task is either to make a diagnosis or to suggest how the diagnosis can be reached.  I could do neither.

About ten years ago I set out on a very indirect route to making that diagnosis.  I can now make it.  When I set out I had only my personal resources and no idea where to turn, but it did not take long to pick up the trail.  I would have thought that the answer would be received with enthusiasm, but I have instead found almost universal indifference or outright hostility.  What in the world can be wrong with thinking that a healthy woman who wants a child ought to be able to have one?

I shall skip over the years of search and go brutally to the point.  A paper has been published that shows that for animals fertility is a consequence of population size, which translates to the kinship of the average mating pair.  (On the Regulation of Populations of Mammals, Birds, Fish, and Insects, Richard M. Sibly et al. SCIENCE vol. 309 no. 5734  JULY 22, 2005 page 607 – 610)  This is unrelated to environmental limitations and of course has nothing to do with the animals choosing to have offspring.  It turns out that the smaller population experiences faster growth.  This fertility falls rapidly as the population increases.  The fall levels off below replacement level at a shockingly small population size – less than 1,000 in the example they offered. 

The identical phenomenon was found in humans.  (An Association between Kinship and Fertility of Human Couples Agnar Helgason et al. SCIENCE vol. 329 no. 5864 February 8, 2008 page 813 – 816)  Fertility declined below replacement levels before 8th cousins were reached, so again the largest viable random mating pool is less than 1,000.  If more evidence were needed, a subsequent study showed the same relationship in Denmark.  (Comment on “An Association between Kinship and Fertility of Human Couples,” Rodrigo Labouriau et al. SCIENCE vol. 322 no. 5908 12 December 2008 page 1634 – 1635)  The curve was the same although no estimate of critical population size was possible. 

The science thus is known.  But just about everybody seems to take the attitude, “Women don’t have babies because now they have choice.”  Am I supposed to say to my patient, “You can’t get pregnant because you don’t want to”?  That would be absurd.  But I now should be able to say, “You can’t get pregnant because you married a man who is not a near enough relative, or your parents were not closely enough related, or his were not closely enough related or most likely all three, and it probably extends to previous generations as well.” 

Well that news would be about as welcome as the first possibility.  The difference is that it is the truth.

But science is more than a matter of truth.  It is also a matter of consensus.  There is no consensus.  There is indifference.

I have written Dr. Francis Collins, director of the NIH, more than once trying to find some interest, since this is clearly a matter of the utmost public concern.  I have found no interest.  On the way home from the meeting I happened to fall into conversation with a man who said he knew Dr. Collins well.  I began to explain the phenomenon to him.  He said, it seemed to me a bit too quickly, that he understood and would pass the word along.  I expect no response. 

It comes down to physicians.  We are the ones who are supposed to take the needs of our patients to heart before all else.  I have had no success in getting any interest from specialists in fertility, even though I have an old friend, Dr. Carl Herbert, who runs a very large fertility clinic on the west coast.  At least he was willing to communicate with me for a while.  No one else I have tried will even come to the phone.

When I started out it was with little sense of urgency.  After all, in those days we were told that it was all choice and besides there were too many babies in the world anyway.  The choice notion is no longer tenable, and world fertility is plummeting.  It has taken us generations to get into trouble and for all I know it will take generations to recover if it is even possible.  After all, as decades fall behind us in which the birth rate is below replacement (as it is in developed countries) the cousin pool dries up. 

What is needed is a scientific paper that lays it all out.  I don’t see that happening, but I would be more than happy to join anybody who was willing to try.  I have only published one paper, and that was as a resident.  It was made clear to me then that publishing is not a level playing field.  My paper got into RADIOLOGY only because the professors in my department wanted it to. 

What might happen would be a conference on the issue.  Unfortunately the experts I cite above are in England, Iceland and Denmark, so it would take a rather well funded conference to fly them in.  I once would have paid for it without hesitation, but the quest has depleted me to the point that this would be foolish even for me.  I am not sure they would even come.  Rusty, I mean Carl, might.  Dr. Evans who edits the journal of the American College of Medical Genetics did not seem to be frightened.  Dr. Robin Fox is an anthropologist who has written a book on incest and seems not to be in a panic.  Martin Ottenheimer is another anthropologist who has said that throughout history 99 percent of people have married cousins. 

Of course this has nothing to do with incest.  Nor has it anything to do with race.  Once you get past about 10th cousins no further separation seems to have any effect.  The phenomenon does seem to accumulate over multiple generations but so far as I can tell the rate of accumulation is independent of the degree of separation.

If you want more evidence I can send it.  There is a mass of data piled up at, but that is probably too much to digest.

So what can be done?  We are doctors.  How do we serve our patients in this important matter?


M. Linton Herbert  

Feel free to make any use of this you like.  None of it is guarded.  In fact I shall post this on my web log unless you object. 

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