Effect of hypothyroidism on ovarian reserve status in Iraqi women: hormonal study

Background: Hypothyroidism is a clinical syndrome prevalent in women, even those of reproductive age. Ovarian reserve can be defined as the number and quality of follicles in the ovary at any given time. Evaluation of ovarian reserve is recommended for patients at risk of decreased ovarian reserve. Objective: This study aims to evaluate the effect of hypothyroidism on ovarian reserve in Iraqi women by hormonal measurements of serum anti-mullerian hormones AMH, FSH, and LH. Subjects and methods: This case–control study was carried out at the Department of Biochemistry, College of Medicine, University of Baghdad, in collaboration with Endocrinology and Diabetes Clinic, Baghdad Teaching Hospital, and National Center for Teaching Laboratories, Medical City, during the period from November 2021 to March 2022. This study involved 88 women, age range (20-40 years). Fifty-one of them [Group I (GI)] had primary hypothyroidism and were diagnosed by an endocrinologist based on clinical analysis and thyroid function tests, including serum TSH, T4 and T3. Patients with symptoms and signs suggestive of hypothyroidism and elevated TSH with T4 less than the reference level were considered overt hypothyroidism. While patients with elevated TSH with standard T4 and T3 were considered subclinical hypothyroidism 1 , serum thyroid peroxidase antibody (TPOAb) was used to differentiate hypothyroidism patients with Hashimoto`s disease 2 . Thirty-seven of the included women were healthy and served as a control group and referred to group II (GII). Results: The mean (±SD) value of serum AMH of hypothyroidism women was significantly lower than that of controls (p < 0.0001). However, the mean value of AMH did not differ significantly between women who had overt and subclinical hypothyroidism, regular and irregular menstrual cycle, well and poorly controlled thyroid status, and who had positive and negative anti-TPO. The mean (±SD) value of serum LH of hypothyroidism women was significantly higher than that of the control group (p < 0.004), while that of FSH did not differ significantly. Serum TSH levels positively correlated with LH levels (r=0.3, p 0.03). In addition, BMI values were significantly positively correlated with FSH levels (r= 0.3, p 0.04). Conclusions: This study suggested the need for serum measurement of AMH in women suffering from hypothyroidism. Keywords: hypothyroidism, ovarian reserve, AMH.