tttiltheend wrote:
I really can't give any more details about the anecdotes (and note that I'm using plural) that I have personal experience with, but let's just say they are extremely cautionary regarding extended, long distance exercise during pregnancy, but not cautionary at all about moderate exercise. I did a little research on this and as is usual you can find data to support whatever you believe in. There was a study in Denmark published in 2007 that found a correlation between strenuous exercise in the first trimester and miscarriage. Other studies have not found a link.
One thing to keep in mind is that what we may regard as moderate exercise might be another person's extreme exercise. If a couple is consulting with their doctor for advice on this issue, just make sure to communicate very clearly; an athlete might think "moderate" is dropping the weekly hours from 25 to 15 and cutting back a bit on L6-7, whereas the doctor might be thinking "moderate" is up to an hour a day of L1-2.
Doctors are highly conservative. Of COURSE they would recommend for less. Even if the evidence clearly said there was no risk, if something bad DOES happen, even if it's unrelated, they'll highly likely to be sued for it regardless.
I'm not saying that pregnant women should up and run ultras at 8 months, but I do think the data out there is sparse at best, and not at all as strong as you suggest it is against running. It is very hard to make a good study based on the small numbers of women who actually run marathons pregnant.