A Pregnant Woman (IMAGE) University of Granada Caption UGR researchers have proven that hair cortisol levels, which is a steroid hormone secreted as a response to stress, are higher in the first and third trimesters of pregnancy for those women that will later suffer postpartum depression Credit UGR Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.