Thyroid autoimmunity and its negative impact on female fertility and maternal pregnancy outcomes

Abstract

Thyroid autoimmunity (TAI) is commonly defined as the presence of thyroperoxidase antibodies (TPOAbs) and/or thyroglobulin antibodies (TgAbs), which predisposes an individual to hypothyroidism. TAI affects nearly 10% of women of reproductive age and evokes great interest from clinicians because of its potentially negative impact on female fertility and pregnancy course. In this mini-review, we review the current literature concerning the influence of TPOAb or TPOAb/TgAb positivity without thyroid dysfunction on reproduction. TAI may negatively affect female fertility; several studies have found an increased prevalence of TAI in infertile women, especially in those with unexplained infertility and polycystic ovary syndrome. According to some observations, TAI might also be connected with premature ovarian insufficiency and endometriosis. The relationship between TAI and an increased risk of pregnancy loss is well documented. The pathophysiological background of these observations remains unclear, and researchers hypothesize on the direct infiltration of reproductive organs by thyroid antibodies, co-existence of TAI with other autoimmune diseases (either organ specific or systemic), immunological dysfunction leading to inhibition of immune tolerance, and relative thyroid hormone deficiency. Interestingly, in the current literature, better outcomes of assisted reproductive technology in women with TAI have been reported compared with those reported in earlier publications. One plausible explanation is the more widespread use of the intracytoplasmic sperm injection method. The results of randomized clinical trials have shown that levothyroxine supplementation is ineffective in preventing adverse pregnancy outcomes in women with TAI, and future research should probably be directed toward immunotherapy.

A new prognostic model for recurrent pregnancy loss: assessment of thyroid and thromboelastograph parameters

“…Furthermore, immune abnormalities linked with thyroid diseases, particularly thyroid autoimmunity (TAI), are connected to an elevated risk of RPL in women (43). TAI can induce immunological dysfunction and impede immune tolerance at both systemic and maternal-fetal interface levels (44). Additionally, thyroid autoantibodies, particularly TGAb, could be an expression of a more general maternal immune system abnormality leading to RPL (45).…”

Subfertility as Overlapping of Nutritional, Endocrine, Immune, and Cardiometabolic Dysregulations—A Study Focused on Biochemical Endophenotypes of Subfertile Couples

“…Anti-TPO positivity is a marker of autoimmune thyroid disorders (Graves’ Disease and Hashimoto Thyroiditis) and is linked with male and female subfertility, even in subjects with biochemically normal thyroid function [ 64 , 65 ]. Thyroid autoimmunity has been mentioned in various possible pathogenetic mechanisms: premature ovarian aging with lower anti-Müllerian hormones, an increased risk of ovarian hyperstimulation, antiphospholipid antibody syndrome, cross-reactivity between anti-thyroid and anti-zona pellucida antibodies, endometriosis, genetic components, and systemic immune dysfunction with inhibition of immune tolerance [ 63 , 66 , 67 ]. A meta-analysis of four studies showed that among antibody-positive euthyroid women, the risk of unexplained infertility is increased (OR 1.5, 95% CI 1.1–2.0) [ 68 ].…”

Minerals and the Menstrual Cycle: Impacts on Ovulation and Endometrial Health

“…Selenium is essential for the production of selenoproteins, which are crucial for the conversion of the thyroid hormone thyroxine (T4) into its active form, triiodothyronine (T3) [60,63]. The proper transformation of T4 to T3 is central for regulating metabolic rate and numerous cellular processes within the body [61,64,[107][108][109]. Proper thyroid function is crucial for a balanced hormonal environment in the female reproductive system [110].…”