According to study results published in The Journal of Clinical Endocrinology and Metabolism, pregnant women in their third trimester with polycystic ovary syndrome (PCOS) have higher total testosterone and free testosterone levels than women without PCOS.
As part of a broader prospective study, researchers sought to compare total testosterone, free testosterone, and sex hormone binding globulin levels in 145 pregnant women in their third trimester with PCOS and 1341 controls. The investigators collected fasting blood samples from each participant at gestational week 28 and measured plasma total testosterone via liquid chromatography-tandem mass spectrometry.
Compared with controls, total testosterone levels were higher on average in women with PCOS (2.4 vs 2.0 nmol/L), as were free testosterone levels (.005 vs .004 nmol/L). However, sex hormone binding globulin levels were found to be lower in women with PCOS (447 vs 477 nmol/L) (P <.001 for all comparisons). These differences all remained significant when women were categorized according to offspring gender.
According to the researchers, partitioning of reference intervals was an ambiguous decision, and reference intervals for total testosterone, free testosterone, and sex hormone binding globulin overlapped between groups. Via multiple regression analysis, researchers determined that total and free testosterone levels were positively associated with PCOS status and body mass index and inversely associated with age and parity. Offspring gender was found not to predict maternal testosterone levels.
Study limitations included potential misdiagnosis of PCOS and idiopathic hirsutism.
“We found that twice as many women with PCOS compared to controls had free testosterone levels above the reference interval for controls,” the researchers said. They added, “Our study therefore supports that partitioning of reference intervals for free testosterone should be considered. The importance of measuring testosterone levels during pregnancy remains to be established.”
Glintborg D, Glintborg D, Jensen RC, et al. Testosterone levels in 3rd trimester in polycystic ovary syndrome. Odense Child Cohort [published online July 27, 2018]. The J Clin Endocrinol Metab. 10.1210/jc.2018-00889