Physical activity increases rates of successful pregnancy in obese women using IVF or ICSI

This study examined whether physical activity, as opposed to weight loss, increased fertility in obese women undergoing assisted reproduction.

Obesity is associated with a number of chronic conditions and can also affect fertility. Obese women may find that it takes longer to conceive than non-obese women, and obesity has been correlated with higher rates of pregnancy complications and miscarriage. While weight loss overall has been shown to regulate ovulation and increase rates of spontaneous conception (without the help of assisted reproductive techniques), it is not clear whether an increase in physical activity has a direct effect on pregnancy in obese women. The current study examined the association between physical activity and fertility in obese women undergoing assisted reproductive techniques.

This study examined the treatment records of 216 patients who underwent in vitro fertilization (IVF; when the egg is fertilized outside of the body) or intra-cytoplasmic sperm injection (ICSI; when the sperm is injected directly into the egg prior to IVF). Patients with a body mass index (a measure of body fat based on weight and height) higher than 30 kg/m² were considered obese. Patients filled out questionnaires at both the time the treatment was scheduled and when the procedure occurred. The level of physical activity was categorized based on the answers.

There were no significant differences among the different levels of physical activity in the rates of fertility or miscarriage.

Implantation rates significantly differed, with 22.7% of women reporting a higher amount of physical activity having a successful implantation, compared to 6.9% in women with low amounts of activity. Clinical pregnancy (a positive pregnancy test) was seen in 29.3% of active women compared to 9.1% of non-active women, and live births occurred in 24.4% of active women, compared to 7.4% of non-active women.

Overall, regular physical activity in obese patients was associated with 3.22 times the chance of a clinical pregnancy and 3.71 times the chance of a live birth compared to lack of regular physical activity.

This study concluded that physical activity improved assisted reproductive outcomes in obese women.