Want a baby bump? Consider bumping up the body fat!
As the winter months approach, many couples may start to think about baby making (wink, wink!). It can be disappointing when despite best efforts, it doesn't work out. Infertility has been linked to a number of genetic and environmental factors, many out of our control. It's helpful to look at the variables that we may have some ability to influence. For example, did you know that the amount of fat on a woman's body impacts fertility? There's a lot of focus (no suprise here) on how overweight contributes to pregnancy outcome but there are significant (perhaps even greater) consequences to women not carrying enough body fat before and during pregnancy.
Menstruation won't occur unless a woman has a minimum of 17% body fat. More importantly, ovulation ceases at at body fat of < 23%. Most fully developed females have at least 26% body fat. This is healthy and adaptive; we need it to reproduce. Reproductive function shuts down when there is not enough energy present via food intake and/or body fat storage.
Many woman who lose a modest amount of weight (10-15%) as well as those with anorexia (less that 30% of ideal weight) develop either primary or secondary amenorrhea. Primary amenorrhea is when a girl has not menstruated by age 16. This often occurs in female athletes who, despite being at a healthy weight determined by BMI, do not carry enough fat on their bodies. Muscle is heavier than fat since it holds a lot more water; 80% compared to 5-10% in adipose (fat) tissue. A normal weight athletic girl who lacks enough body fat to menstruate can easily go under the radar. In addition to reproductive function, a natural menses indicates there is adequate estrogen in the body for bone formation and growth, a very important factor for adolescent girls who are at the stage of peak bone growth.
Secondary amenorrhea is when a female begins menarche but then stops menstruating in response to hormonal shifts, often relating to body composition. Primary or secondary anorexia is caused by hypothalamic dysfunction and can be set off by weight loss. The hypothyalamus is the region of the brain responsible for body temperature regulation, growth, sleep regulation, emotions, child birth, weight and appetite. Read more about hypothalamic dysfunction here. Interestingly, many women start dieting when they think about getting pregnant because of the importance placed on being at your ideal body weight to conceive. It's important to remember that "ideal" varies from one person to the next.
In our practice, we frequently see women who are at a healthy weight but not menstruating. Recently, we purchased a piece of equipment, the InBody™ which measures all components of body composition in addition to weight; muscle and lean mass, body water and body fat. By using this analysis, we have been able to determine more specifically, what a healthy weight is for each individual. Body Mass Index (BMI) is misleading because it doesn't take into consideration how athletic an individual is and tends to be less accurate for those on the taller or shorter sides of the height spectrum.
We offer complimentary InBody™ assessments to our patients when it is appropriate. In many cases, clients will get retested every few months. We also offer this service along with a 60 minute consult to explain the results to anyone who wants the assessment. See our Wellness & Sport section to find out more. Insurance often covers the consult portion.