Interrelationships Between FSH, LH, and TSH in Pregnant Women

Abstract

Background: Pregnancy involves dynamic hormonal adjustments essential for maternal health  and fetal development. Among these, Follicle-Stimulating Hormone (FSH), Luteinizing Hormone  (LH), and Thyroid-Stimulating Hormone (TSH) play crucial roles in regulating reproductive and  metabolic functions. Understanding their interrelationship provides insight into the physiological  balance maintained during gestation. 
Objective: To review and analyze existing literature on the interrelationships between FSH, LH,  and TSH in pregnant women, emphasizing physiological regulation, trimester-wise variations, and  hormonal feedback mechanisms. 
Main Body: This study was conducted as a systematic literature review using databases including  PubMed, ScienceDirect, Google Scholar, and Scopus. Studies published between 2020 and 2024  focusing on FSH, LH, and TSH variations in pregnancy were identified and reviewed. Relevant  data were extracted, compared, and thematically analyzed. The review revealed that FSH and LH  levels are markedly suppressed during pregnancy due to high estrogen, progesterone, and placental  hormone activity, while TSH levels fluctuate depending on maternal thyroid status and gestational  age. Several studies indicate a subtle but significant hormonal interdependence between thyroid  function and gonadotropin regulation. However, regional data and combined hormone analyses  remain limited. 
Conclusion: The interaction between FSH, LH, and TSH reflects the complex endocrine  coordination required for maintaining a healthy pregnancy. Further population-based research is  needed to establish reference values and clarify these hormonal relationships to improve early  detection and management of endocrine disturbances in pregnant women.