Serum and follicular fluid thyroid hormone levels and assisted reproductive technology outcomes

Yun Ying Cai,Yun Hua Dong,Lan Ping Zhong,Heng Su,Hui Juan Duan,Ze Wu,Na Lin

doi:10.1186/s12958-019-0529-0

Abstract

ObjectiveThe objective ofthis study was to assess the association between thyroid hormone (TH) levels in follicular fluid (FF) and serum and to determine whether THs impact assisted reproductive technology (ART) outcomes.MethodsThis study enrolled 299 women undergoing ART. Blood samples were drawn on the day of human chorionic gonadotrophin (HCG) administrationand analysed for thyroid-stimulating hormone (TSH), thyroxine(T4), triiodothyronine(T3),free T4 (fT4),free T3(fT3), thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TGAb) levels. FF was obtained on the oocyte pick up (OPU) day and analysed forTSH, T4, T3, fT4, fT3, TPOAb, TgAb and estradiol levels.Results(1) There were significant positive correlations between serum and FF TH and thyroid autoantibody levels. Statistically significant differences were discovered in serum and FF levels of TSH (p ≤ 0.001), T4 (p ≤ 0.001), T3 (p ≤ 0.001), TPOAbs (p ≤ 0.001) and TGAbs (p = 0.021).(2) Serum T4 levels [121.9(104.8,140.8) vs 114.1(98.6,130.6) nmol/l, p = 0.026], serum fT4 levels[(19.0(17.7,21.8) vs 18.6(17.0,20.1) pmol/l, p = 0.026], serum T4/T3 ratios [62.5 (55.7, 66.2) vs 59.4 (53.4, 64.9), p = 0.029], FF fT4 levels [19.0(17.5,21.3) vs 18.1(16.8,19.9) pmol/l, p = 0.009] and FF T4/T3 ratios [52.6 (46.4, 57.3) vs 50.0 (43.7, 53.1), p = 0.004] were significantly higher in the successful pregnancy group than the implantation failure group.(3) Spearman’s rank correlation analysis revealed positive associations of both the FF T4/T3 ratio and serum TSH levels with the numbers of retrieved oocytes (total or MII) and embryos (fertilized, cleavage, and good quality).ConclusionsTH levels in FF are strongly correlated with those in serum on the HCG day, and THs on the HCG day may affect ART outcomes.

Highlights

Thyroid hormones (THs) are related to infertility and multiple adverse neonatal and maternal consequences [1, 2]
Relationship and difference between serum and follicular fluid thyroid hormones Our results showed significant positive correlation between serum THlevels and Follicular fluid (FF) TH levels (TSH: r = 0.876, p ≤ 0.001;T4: r = 0.788, p ≤ 0.001; T3: r = 0.727, p ≤ 0.001;fT4: r = 0.853, p ≤ 0.001; fT3:r = 0.702, p ≤ 0.001)
Relationship and difference between serum and follicular fluid thyroid autoantibodies Our results showed a significant correlation between serum and FF thyroid peroxidase antibody (TPOAb)(r = 0.808, p ≤ 0.001) and thyroglobulin antibody (TGAb)(r = 0.601, p ≤ 0.001)

Summary

Introduction

Thyroid hormones (THs) are related to infertility and multiple adverse neonatal and maternal consequences [1, 2]. Many studies have evaluated the relationship between ART outcomes and thyroid function [3,4,5]. Changes in the FF levels of hormonesand metabolites have been reported to influence oocyte quality, early embryo development, and subsequent pregnancy [11, 12]. Since biological effects of THs are regulated by deiodinase (DIO) in peripheral tissue [13, 14], serum TH levels do not always predict tissue-specific effects in target organs, and local THs may play a direct role in physiological functions. Data from literature are not sufficiently clear to definitely state the relationship between serum and FF TH levels and the outcomes of assisted reproductive technology (ART),such as in vitro fertilisation (IVF)

Methods

Results

Conclusion