Obesity and the Infertility Connection

What effect does weight have on our lives? It seems you can not pick up a newspaper or turn on the Television or computer without hearing about all the adverse health effects of being overweight. (Overweight is defined as a BMI of 25 to 29.9 kg/m2, obesity as a BMI of >30 kg/m2. Severe obesity is defined as a BMI >40 kg/m2) Diabetes, hypertension, degenerative joint disease, sleep apnea, and cardiovascular disease are all related to increased weight, just to name a few. Something that we do not often hear about is the effect of weight on a woman’s ability to conceive and have full term pregnancy. Infertility, defined as the inability to get pregnant after one year of unprotected sexual intercourse, or six months if the woman is 35 or older. 

According to the Centers for Disease Control and Prevention, infertility affects both men and women equally. Approximately 1/3 of cases are caused by women’s problems and 1/3 of cases are attributed to the men. The remaining 1/3 are unknown or combined male/female problems. Infertility affects approximately 6.2 million women in the United States; this number is expected to rise to 7.7 million women in the next 15 years. 

A woman’s risk of infertility increases with age, smoking, alcohol use, overweight/obese, poor diet/nutrition, stress, excessive athletic training, and hormone related health problems such as polycystic ovarian syndrome (PCOS). PCOS is the most common cause of female infertility and is commonly associated with irregular/infrequent/absent menstrual cycles, obesity, and sometimes acne/facial hair. Irregularities in the menstrual cycle are associated with infrequent ovulation and delayed conception. Many women have regular menstrual cycles in their teens and later develop menstrual irregularity in association with weight gain; they may eventually use medication to induce ovulation. 

When pregnancy is achieved either spontaneously or after infertility treatments, obesity is associated with increased risk of both early miscarriage and recurrent miscarriage. There is also a strong association between obesity and labor & delivery complications. This includes fetal distress, failure to progress, abnormal presentation, and an increased rate of forceps and vacuum delivery or Caesarean section. 

In summary, studies have shown that modest weight loss can have a significant effect on women with PCOS, often resulting in a more regular menstrual cycle. Ideally, weight loss should be accomplished prior to conception and pregnancy. It is believed that weight loss prior to pregnancy may significantly decrease maternal and fetal risks associated with pregnancy.