An obese woman once asked me if her weight could significantly affect her ability to conceive because she had struggled with infertility for two years.
While infertility is caused by a myriad of factors which can be traced to any of the affected couple, your weight may not necessarily hinder your chances of conception. However, in some instances your weight affects your fertility and this is mainly due to hormonal imbalance as a result of obesity or being underweight.
Overweight and obese women have higher level of androgens, higher oestrogen and insulin levels especially if they also have a condition called polycystic ovary syndrome (PCOS). These hormones cause a constitutional imbalance that can impair ovulation.
Ovulation involves the release of an egg from your ovaries, which continues into your uterus to get fertilized by a sperm. However, if the hormones that induce ovulation are not in right balance ovulation will not take place.
The same goes for men and fertility: a study from Harvard University found that overweight and obese men are more likely to produce a lower sperm count than their peers of healthy weight.
Underweight women can have low levels of leptin, an appetite regulating hormone that helps control weight. If the body doesn’t have enough fat available for reproduction, it will halt ovulation as a protection mechanism.
Women who do not ovulate cannot get pregnant under any circumstances. Akashia Anderson of the Vanderbilt University Psychology Department, Nashville, Tennessee says that women who have even 10 to 15 percent too little body fat may have either irregular menstrual cycles or a complete cessation of menstruation.
You typically need at least 17 percent total body fat to ovulate regularly. According to BabyCenter, if there is too little body fat, it could disrupt the hormone flow from the brain to the pituitary glands that encourages the ovaries to release an egg. In this case, you will not ovulate or get your period.
Some women who are underweight can go for many years without having a period, while some women may experience infertile bleeding. So getting a monthly period is not necessarily an indication that you are fertile.
Fortunately, getting to a healthy weight should improve your chances of conception.
The easiest way to tell if you’re a healthy weight for your height is to find out your body mass index (BMI). You can calculate your BMI by dividing your weight in kilograms (kg) by your height squared in metres (m²). BMI between 18.5 and 25 is considered to be ideal.
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