Difficulty carrying a baby to full-term when pregnant affects more than 7.3 million women of child-bearing age in the United States alone.
Obesity and infertility
Being overweight or obese can lead to imbalances in reproductive hormones. These imbalances from excess weight can effect menstrual cycles and result in infertility. However, the exact way that obesity impairs ovulation and fertility is not fully understood.
A condition called polycystic ovary syndrome (PCOS) is also linked with obesity and weight gain and can interfere with the ability to conceive. PCOS is characterised by a group of signs and symptoms (e.g. irregular menstruation, increased testosterone levels, insulin resistance, excess body hair, acne, and weight gain) that can occur in any combination. Medical experts recommend losing weight as the first line of treatment for PCOS; weight loss has been shown to improve both fertility rates and pregnancy outcomes.
Obesity is also connected to having a poorer response and weaker absorption of fertility drugs. As a result, higher doses are often needed which may not be as effective for conception.
Obesity can affect men’s fertility as well. A 2005 study with 520 men found that as body mass index (BMI) increased, sperm count and semen quality decreased.
Obesity and pregnancy risks
Research shows that being overweight or obese during pregnancy increases risks for both mum and baby with the risks rising as the degree of overweight increases. Complications for mum due to excess weight include increased risk of high blood pressure, gestational diabetes, C-section, and more difficult deliveries. Complications for baby include increased risk of higher birth weight, being admitted to the intensive care unit, and around double the risk of having a neural tube defect if the mother has a BMI greater than or equal to 30.
For these reasons, the American College of Obstetricians and Gynecologists (ACOG) recommend that obese or overweight women should undertake a weight-loss program before trying to become pregnant. Even a modest weight loss aimed at moving from obese to overweight may have a positive impact on pregnancy.
The bottom line
Excess weight can have a negative effect on a couple’s ability to have a healthy baby. However, focusing on making lifestyle changes to lose weight will not only improve health, but may also positively affect future fertility.