Women who have polycystic ovary syndrome - the most common hormone disorder in women of reproductive age - are more likely to experience chronic low-grade inflammation during pregnancy than counterparts who do not have the condition, according to a new study published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM).

Polycystic ovary syndrome, or PCOS, is a leading cause of infertility. Symptoms can include irregular or absent menstrual periods, infertility, weight gain, acne, excess hair on the face and body, or thinning hair on the scalp. About 5 million women in the United States have PCOS, according to the National Institutes of Health.

"Women who have PCOS often exhibit low-level inflammation," said one of the study's authors, Stefano Palomba, MD, of the Arcispedale of Santa Maria Nuova of Reggio Emilia in Reggio Emilia, Italy. "Our research found this state of inflammation worsens during pregnancy."

The prospective controlled clinical study tracked biological markers of inflammation in 150 pregnant women who had PCOS and 150 pregnant women of about the same age and body mass index.

Researchers found expectant mothers with PCOS had significantly higher markers of inflammation, including white blood cell counts and C-reactive protein. Although most women experience a rise in these biomarkers during pregnancy, the increase was larger among women who had PCOS.

"Other studies have identified a connection between inflammation biomarkers and pregnancy complications such as pre-eclampsia and gestational diabetes," Palomba said. "The abnormal inflammation seen in women with PCOS may be a factor in the development of these conditions."