Pregnancy Over 40, Miscarriage Over 40I have written numerous times about how strenuous exercise may increase the chance of miscarriage which has been written about in the literature.
Myt site: www.getpregnantover40.com
However, this interesting article questions some of the findings or at least tries to clarify how the study was done and whether or not they took other factors into account. Read more:
From the article:
There are several issues worth considering before assuming that exercise increases the risk of miscarriage.
Previous history of exercise not taken into account
The researchers do not appear to have asked the women whether they had exercised prior to their pregnancy. We are unable to determine whether strenuous exercise in itself is a risk factor for miscarriage or whether it is only a risk factor if the woman has exerted herself more in pregnancy than she normally would...
...Healthy pregnancies may lead to more women stopping exercise
The authors point out another source of bias. It is well documented that women with healthy pregnancies are more likely to experience nausea in the first trimester, when compared with women who will subsequently miscarry. If women experience nausea, they may be more likely to stop strenuous exercise in early pregnancy because they feel ill. This would mean that rather than the exercise being a cause of the miscarriage, it was possible because the woman was going to miscarry anyway.
Number of minutes of exercise is different from intensity of exercise
The authors asked women in the interviews how many minutes of exercise they did. However, they did not ask the women what levels of intensity they used when exercising. Two women doing an aerobic workout may do it at very different levels. Walking and hiking were included in low impact exercise for example, but there is a significant difference between walking to pick the kids up from school and hiking in the forest. Without knowledge of intensity of exercise it is difficult to draw any conclusions simply from the number of minutes that a woman exercised.