In a nutshell
This analysis looked at which factors influence the risk of miscarriage for women with polycystic ovarian syndrome (PCOS) who were undergoing infertility treatment. It found that being overweight and insulin resistance can increase miscarriage risk in these patients.
Metabolism, hormones, and fertility are closely connected. For women, when these factors are out of balance it can lead to a collection of symptoms known as PCOS. Women with PCOS do not ovulate frequently and may have high levels of testosterone and similar hormones. PCOS is more common for women with obesity, and the condition can also cause weight gain. Additionally, women with PCOS are more likely to have insulin resistance (IR). The hormone insulin controls the amount of glucose (sugar) in the blood. IR is related to obesity, and IR can also lead to higher testosterone for some women.
It can be more difficult for women with PCOS to become pregnant. This is in part because they ovulate irregularly or not at all. For these women, one option is the infertility treatment in vitro fertilization (IVF). However, IVF leads to more miscarriages than natural conception. This is particularly concerning for women with PCOS, who already have higher rates of miscarriage than other women. However, it is not clear whether IR or obesity further increase miscarriage for women with PCOS.
Methods & findings
This review combined data from 22 studies of 11,182 women. All of the patients had PCOS and were undergoing IVF or a related technique. None of the patients were using medication to treat PCOS, such as metformin (Glucophage). The studies noted how many women who became pregnant later miscarried.
How body weight affects miscarriage was looked at by 15 studies of 7499 patients with PCOS. Patients who were overweight or obese had significantly more miscarriages (48% higher odds) compared to normal-weight women. There was no difference in miscarriage rate between overweight and obese women.
The effect of IR was looked at by three studies of 1393 patients. IR increased the risk of miscarriage for patients with PCOS.
Androgens are hormones which are higher in men, including testosterone and DHEAS. While it is common for women with PCOS to have high androgens, not all do. Four studies of 1,452 patients looked at whether androgen levels affected miscarriage. They found a trend toward more miscarriages for women with both PCOS and high androgens.
The bottom line
This analysis found that IR and high body weight may increase miscarriage for women with PCOS.
The fine print
Some of the studies conducted in China used the Chinese standards of overweight and obesity. This definition includes people as obese at a lower weight than the World Health Organization’s definition. However, this difference did not alter the overall findings of the review.
Published By :
Frontiers in Endocrinology
Dec 22, 2020