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Model Adjustment for BMI

Posted by cnspracklen on 19 Dec 2014 at 17:27 GMT

I would be interested to see the results of your statistical analysis if you adjust your models for pre-pregnancy BMI. While I agree that pre-pregnancy BMI is correlated with energy intake prior to pregnancy, the American College of Obstetrics and Gynecology has very specific guidelines as to how much weight a woman should gain during pregnancy based on her pre-pregnancy BMI that ranges from up to 40 pounds for women with a BMI < 18 but only 11-20 pounds for women with a BMI > 30. Evaluating the sex ratios between BMI groups isn't enough to answer the question as to whether or not BMI is a confounder in this relationship.

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RE: Model Adjustment for BMI

knavara replied to cnspracklen on 19 Dec 2014 at 19:13 GMT

Thanks for your comment. I completely agree that incorporating pre-pregnancy BMI into the model would add some clarification. Unfortunately, we did not have access to the pre-pregnancy BMI data for the same women for which we had data on gestational weight gains for a majority of the years. The CDC only began posting the pre-pregnancy BMIs in the most recent year or two. However, in future years, I think it would be helpful to gather those data to run more detailed analyses.

No competing interests declared.