Effect of Hypothyroidism on Menstrual Cycle Pattern and Fertility at a Tertiary Care Centre in South India

Introduction: Thyroid disorders are very common in females and are known to prevent ovulation. Thyroid disorders can impact menstrual cycles and causes menstrual irregularities and infertility in females. Aim: To determine effects of hypothyroidism on menstrual cycle pattern and prevalence of subfertility among women having thyroid dysfunction. Materials and Methods: This cross-sectional study was conducted in Department of Obstetrics and Gynaecology in collaboration with Department of Endocrinology in Government Medical College, Datia Madhya Pradesh, India from July 2019 to June 2021. A total of 205 patients aged 18-45 years were taken. Among them, 116 and 89 patients were of hypothyroid and euthyroid respectively. After properly selecting patients, detailed history of their menstrual cycles was taken and effect of thyroid dysfunction on menstrual irregularities was assessed. The collected data were evaluated and analyzed using Statistical Package of the Social Sciences (SPSS). Results: A total of 205 patients participated in present study. Mean age was 35+/-5 years. Among 205 subjects, 116 were hypothyroid and 89 were euthyroid. Among the hypothyroid subjects, 72 (62.1%) had normal menstrual cycles, 23 (19.8%) had history of oligomenorrhea, 12 (10.3%) had polymenorrhea, and 9 (7.7%) had amenorrhea, while among the thyroid subjects, 76 (85.4%) had normal menstrual cycle, 6 (6.7%) had oligomenorrhea, 5 (5.6%) had polymenorrhea, and 2 (2.2%) had amenorrhea, with statistically significant differences (p<0.001). The proportions of primary 13 (11.2%) and secondary 9 (7.7%) subfertility were significantly higher among hypothyroid subjects compared with thyroid subjects (p<0.05). The prevalence of subfertility was 7 (7.8%), 10 (14.28%), and 12 (26.08%) among the thyroid, overtly hypothyroid, and subclinical hypothyroid subjects, respectively. Conclusion: In this study, effects of thyroid dysfunction were presumably significant on menstrual cycle pattern and fertility; therefore, thyroid status should be assessed in all patients with menstrual disorders and appropriate treatment should be initiated early.