Pre-pregnancy weight is important to your ability to conceive and carry a child. Being either underweight or overweight can contribute to infertility. If you are able to become pregnant, certain health complications can arise as a result of being an unhealthy pre-pregnancy weight.
Significance
Women of a healthy weight usually have an easier time conceiving. A healthy weight can be defined as being solidly within the normal range of body mass index (BMI) charts, which measure weight in relation to height. According to the experts at babycenter.com, women who have a BMI below 20 or above 30 have a greater challenge getting pregnant. Your weight affects your conception ability, whether you are trying naturally or need medical assistance such as in vitro fertilization.
Underweight
Being too thin---even just ten percent underweight---can cause irregular menstrual cycles and hormone production. Whether your underweight condition is due to exercise, extreme dieting or your natural state of being, the hypothalamus, which regulates the body's hormone production, determines that the body is too low in body fat to support a pregnancy. Hormone production can become irregular and will not coincide with ovulation, making it difficult, and sometimes impossible, to conceive.
Underweight women who are able to conceive are at risk of giving birth to babies of low birth weight. Lead author Zahra Yekta found in a study involving 270 women that those with a pre-pregnancy BMI below 19 were more likely to give birth to babies with a significantly low birth weight. The findings were published in the "Internet Journal of Health" in 2005.
Overweight
Overweight and obese women also suffer from fertility complications. Experts link polycystic ovarian syndrome (PCOS), a hormonal disorder, to higher BMIs. Even if an overweight woman does not have PCOS, she may experience fertility complications like high levels of androgens (male hormones) and insulin resistance. Overweight women have more trouble controlling weight gain during pregnancy. Doctors often recommend obese women gain no weight at all during pregnancy.
Expert Insight
Authors S. Pandey and S. Bhattacharya concluded in a January 2010 edition of the British journal "Women's Health" that high BMIs in women correlate with a higher risk of ovulatory problems and poor responses to fertility treatment. In a 1996 study published in "Human Reproduction," lead author Michaela Hollmann found that in 58 overweight, infertile women, 80 percent of those who followed a successful weight loss program improved their menstrual function and 29 percent succeeded in conceiving.
Solution
If you are ten percent or more underweight, increase caloric intake in order to encourage weight gain. Be sure to eat at least three meals a day and snack on nutrient-rich foods like whole grains, lean proteins and monounsaturated fats to ensure optimal health. Just because you are underweight does not mean you should forego exercise. Instead seek moderate-strength training workouts to help you build up muscle mass.
Women who are 20 percent or more above a normal BMI should seek to lose weight before trying to conceive. Crash dieting and fad diets are not recommended. Rather, follow a nutritionally sound reduced-calorie diet in combination with moderate exercise. Seek the guidance of your OB-GYN in selecting a diet that provides enough calories yet will still yield weight loss.
