Paternal Subclinical Hypothyroidism Affects the Clinical Outcomes ofIn VitroFertilization/Intracytoplasmic Sperm Injection

Abstract

Background: Maternal subclinical hypothyroidism (SCH) is a risk factor for adverse pregnancy outcomes. However, it is still unclear whether SCH affects male fertility. The aim of this study was to determine the association between paternal SCH and clinical outcomes after in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). Methods: This retrospective study included 2511 couples with paternal euthyroidism (n = 2282) or SCH (n = 229) who visited our clinic for infertility treatment between April 1, 2017, and September 30, 2019. The primary outcomes were the fertilization rate and clinical pregnancy rate; the secondary outcomes were the good-quality embryo rate, blastocyst formation rate, implantation rate, and early miscarriage rate. These outcomes were compared between the euthyroid and the SCH groups after adjusting for various potential confounders. Results: The mean paternal ages in the euthyroid and SCH groups were 34.5 and 36.0 years, respectively (p = 0.002). Semen parameters and sperm DNA fragmentation index were similar between the two groups (all p > 0.05). The adjusted fertilization (0.69 vs. 0.71, p = 0.30), good-quality embryo (0.49 vs. 0.52, p = 0.31), blastocyst formation (0.51 vs. 0.53, p = 0.57), and early miscarriage (0.11 vs. 0.10, p = 0.81) rates were also similar between the two groups. There was a significantly decreased adjusted clinical pregnancy rate [confidence interval, CI] and implantation rate [CI] in the paternal SCH group compared with the euthyroid group (0.32 [0.26-0.40] vs. 0.42 [0.40-0.45], p = 0.009 for the clinical pregnancy rate; 0.24 [0.19-0.29] vs. 0.29 [0.27-0.31], p = 0.037 for the implantation rate). Stratified analysis indicated that these differences were only significant in men aged ‡35 years (p = 0.009 and 0.022, respectively) and not in men <35 years (p = 0.39 and 0.45, respectively). Conclusions: Paternal SCH was associated with worse clinical outcomes after IVF/ICSI, whereas this detrimental impact was only present in males ‡35 years old. Prospective studies and basic research are warranted to confirm these results and to clarify the mechanisms underlying these associations, respectively.

Cumulative live birth rates after IVF/ICSI cycles with sperm prepared by density gradient centrifugation vs. swim-up: a retrospective study using a propensity score-matching analysis

“…Different protocols were used for ovarian stimulation according to the woman’s condition. The details of these protocols, including the use of gonadotropin-releasing hormone agonist or antagonist or other protocols (mild stimulation and progestin-primed ovarian stimulation), have been described in our previous study [ 35 ]. After retrieval, oocytes were fertilized via conventional IVF or ICSI.…”

Hypothyroidism in canine reproduction

“…Men who were > 35 years and subclinically hypothyroid had decreased clinical pregnancy rate when compared with their euthyroid counterparts. 14 Although these findings are valid, it is important to notice that human and canine pregnancies are very different. Humans have higher concentrations of thyroxine binding globulins (TBG) and placental deiodinases; both drastically increase the metabolic demand for thyroid hormones during pregnancy.…”

“…Reports include abnormal cyclicity or anovulation, infertility, loss of pregnancy in women, and loss of libido or fertility in men. 13,14 Women who did not receive adequate supplementation of thyroid hormones or who have had impaired iodine intake during pregnancy had children with substantial effects, 15,16 particularly impaired cognitive function. The relation between thyroid hormone supplementation and diet is being elucidated in women.…”

Thyroid diseases and fertility disorders — Guidelines of the Polish Society of Endocrinology [Choroby tarczycy a zaburzenia płodności — rekomendacje Polskiego Towarzystwa Endokrynologicznego]

“…However, among couples in which the man suffered from subclinical hypothyroidism, significantly lower clinical pregnancy and embryo implantation rates were observed. When stratified by age, this effect was found only in the case of males aged 35 years or older [49]. There are no available studies evaluating the effect of L-thyroxine treatment of males from infertile couples on the outcome of ARTs.…”

“…Natomiast wśród par, w których mężczyzna chorował na subkliniczną niedoczynność tarczycy, zaobserwowano istotnie niższy odsetek klinicznych ciąż i odsetek implantacji zarodków. Po wykonaniu stratyfikacji według wieku efekt ten stwierdzano jedynie w przypadku mężczyzn w wieku 35 lat lub starszych [49]. Nie ma dostępnych wyników badań oceniających wpływ leczenia L-tyroksyną mężczyzn z niepłodnych par na wyniki procedur ART.…”