Reproductive endocrinology is a medical field related to infertility, menopause, and other issues with reproductive hormones. This speciality is also called reproductive endocrinologist and infertilitist work is focused on helping women to become pregnant and carry a baby to term. Reproductive endocrinologists, or REs, are fertility/infertility specialists. These doctors were trained in providing fertility treatments using assisted reproductive technologies (ART) such as in vitro fertilization (IVF) and egg freezing. REs diagnose and treat infertility, polycystic ovary syndrome (PCOS), or abnormalities of the reproductive system, and perform fertility preservation procedures like egg freezing.