Hormonal Profile in Infertile Women and Its Association with Menstrual Irregularity: A Case-Control Study
Abstract
Background: Endocrine dysfunctions, including disturbances in gonadotropins, thyroid hormones, and prolactin, are important contributors to female infertility and may adversely affect reproductive function and menstrual regularity. Objectives: To determine the prevalence of hypothyroidism and hyperprolactinemia, compare hormonal profiles between infertile and fertile women, investigate the relationship between thyroid-stimulating hormone (TSH) and prolactin, and assess the association of hormonal abnormalities with menstrual irregularity. Methods: This case-control study was conducted by the Department of Biochemistry at Quaid-e-Azam Medical College, Bahawalpur, from January to June 2025, and included 120 women with primary infertility and 120 fertile controls. Fasting blood samples collected during the early follicular phase were analysed for FSH, LH, TSH, free T3, free T4, and prolactin using standardized immunoassays. Data were analysed using SPSS version 26. Results: Median TSH levels showed no significant difference between infertile and fertile women [2.88 (IQR=2.79–2.95) vs. 2.83 (IQR=2.78–2.88) mIU/L, p=0.058]. However, median prolactin levels were significantly higher in infertile women (p<0.001). FSH and LH levels were lower among infertile women (p<0.001). All thyroid dysfunction cases identified were subclinical hypothyroidism. Prolactin approached association with menstrual irregularity but did not reach statistical significance (OR=1.48, 95% CI: 0.99–2.21, p=0.053). Conclusion: Infertile women demonstrated notable hormonal alterations, with elevated prolactin levels being a prominent finding. Although hyperprolactinemia approached association with reproductive dysfunction after multivariable adjustment without reaching statistical significance, the observed positive correlation between TSH and prolactin indicates a potential interplay between thyroid function and prolactin regulation in women with infertility.