What is a healthy BMI? More importantly, what is an ideal BMI for pre-pregnancy and preconception planning? BMI, or body mass index, refers to a heuristic proxy for human body fat based on an individual’s weight and height. BMI does not actually measure the percentage of body fat.
It is important to take note of your BMI, and I would argue, it is far more important than a simple number on the scale. Having a BMI that is higher than recommended can make it hard to conceive, but today I am going to address how being “underweight” or having a low BMI can cause anovulation and other conception issues.
What is a healthy BMI (body mass index) for preconception purposes? This question was on my mind when my husband and I first began the preconception planning process. After doing quite a bit of research and speaking with my doctor, I found out that 18.5 or 19 percent was a healthy BMI while TTC. When I conceived Emma (which was a surprise since I was told it would be difficult or impossible to conceive because of my metabolic disorder), I was slightly underweight. As a result, I was intentional about eating more nutrient-dense foods in the first trimester to gain a couple extra pounds. Many women I train in the gym are very concerned about the number on the scale.
BMI is an indication of being underweight or overweight. However, that being said, if a woman is very athletic and has a lot of muscle weight, her BMI can appear in the overweight category (over 25) since muscle weighs more than fat. Use BMI as an indicator of your health, and consider visiting your doctor if you feel uncomfortable with a number in the underweight or overweight category, etc. Keep the numbers in perspective.
My husband and I do want to conceive again if possible, so I consider myself in preconception planning even now. I try to keep my BMI around 18 or 19% (which means I am a few pounds heavier than I was before I had Emma). Chances are, if you are eating nutrient dense foods and working out 5 times a week for 60 minutes at a time, your body will maintain a healthy BMI and set point. However, if you are currently in a training program (i.e. marathon training) or eating less calories and nutrients than your body needs, it is possible that you will be underweight. If you think you might be in this situation, ask your doctor or to do a health assessment for you.
I added a BMI chart for your reference. Remember, living a healthy lifestyle is the goal – not a certain number on the scale. Best wishes!