[Dr. G]

Dr. G asked the Naked Scientists:
   
I used to think it a joke, but is infertility hereditary?  Are the fertility clinics making future clients?  How is this going to impact evolutionary sexual selection?

What do you think?

[rosy]

Presumably that depends on the cause of the infertility.

I don't have any specialist information on the subject, but from general knowledge:

I'm pretty sure that (for example) PCOS is heritable, and that causes (or can cause) poor-to-nonexistant fertility. I'd expect this applies at least partially to lots of causes of infertility. So in that sense, yes, probably there is a slight increase in the number of children being born who might be expected to have fertility problems. On the other hand at least some of the people who have fertility treatments are infertile due to (say) infections or past cancer treatments which are basically environmental effects.. and an awful lot of women need fertility assistance just because they've left it a bit late and although there may have been nothing wrong with their fertility at 21, by the time they're 38 they need a little help.

The first generation of IVF babies are all grown up now, and having kids of their own.. and the radio 4 programme I happened to hear last night about fertility treatments discussed the old fears that IVF might lead to abnormalities in the children and the fact that these have been shown to be ill-founded. They didn't mention any significant effects on fertility, and given that they also discussed the technique whereby sperm are injected directly into the egg and the possibility that when the children born from that technique reach adulthood (the eldest are currently about 10) there's a possibility the boys may have inherited their fathers' poor sperm motility it seems likely that if there were any effects already being observed for "normal" IVF they'd have been brought up.

Also, of course, the number of people currently undergoing fertility treatments is quite small as a proportion of the population of the western world and much, much smaller on a global scale. So any effect can be expected to be vanishingly small for the forseeable future, and it seems to me unlikely that the global population will ever get it together sufficiently that everyone worldwide gets the same level of medical care and interventions currently available in the UK.