Exercise and Miscarriage: Understanding the Risks & Staying Active During Pregnancy

Question
I have read (on Wikipedia) that exercise may be known to be a link for miscarriage. I used to work out a lot for about an hour and a half a day, but have not since finding out I was pregnant, due to fear of having another miscarriage (i had two chemical pregnancies bot ending at the time my period would have started) but am now 5 weeks 4 days into this pregnancy. This is what I read:

"One such factor is exercise. A study of over 92,000 pregnant women found that most types of exercise (with the exception of swimming) correlated with a higher risk of miscarriage prior to 18 weeks. Increasing time spent on exercise was associated with a greater risk of miscarriage: an approximately 10% increased risk was seen with up to 1.5 hours per week of exercise, and a 200% increased risk was seen with over 7 hours per week of exercise. High-impact exercise was especially associated with the increased risk. No relationship was found between exercise and miscarriage rates after the 18th week of pregnancy. The majority of miscarriages had already occurred at the time women were recruited for the study, and no information on nausea during pregnancy or exercise habits prior to pregnancy was collected."

What is the truth to this? What do you rec. for someone with my apst who like to work out?

Answer
To date, there has been only one study that has found a correlation between exercise and miscarriage in the first trimester. The link was not found with "most types of exercise" but with women who did high volume/high intensity/high impact exercise like running.

However, it is important to note that this link has not been found in any other study (and this has been researched extensively). As most of the miscarriages "had already occurred at the time women were recruited for the study" it is not possible to rule out other factors that might have influenced the findings such as over-all maternal health, previous exercise history, age, previous history of miscarriage, etc. Miscarriage, though potentially emotionally devastating, is the nature's way of cleaning the slate and starting over.

Because of the inherent study limitations, most OBGYNs and fitness professionals still hold the view that fitness activities overwhelming enhance both maternal and fetal health, and that all healthy, pregnant women engage in moderate exercise for a minimum of 30 minutes daily.

The benefits of engaging in fitness activities are numerous, and truly profound, both for you and your developing baby. For this reason I suggest that you resume fitness activities that you enjoy, that are low impact, and of moderate intensity.

For more information on the benefits of maternal fitness go to:
http://befitmom.com/exercise.html

For information on what exercises to avoid during pregnancy go to:
http://befitmom.com/contraindicated_exercise.html

For information on aerobic exercise during pregnancy go to:
http://befitmom.com/aerobic_exercise.html

For information on strength training and core conditioning go to:
http://befitmom.com/strength_training.html