AUTHOR=Liu Yalong , He Zining , Huang Ning , Zeng Lin , Meng Fangyin , Li Rong , Chi Hongbin 

TITLE=Thyroid autoimmunity and vitamin D: Effects on in vitro fertilization/intracytoplasmic sperm injection laboratory outcomes

JOURNAL=Frontiers in Endocrinology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2022.1079643

DOI=10.3389/fendo.2022.1079643

ISSN=1664-2392

ABSTRACT=<p>This prospective cohort study aimed to determine the effects of thyroid autoimmunity, serum/follicular fluid vitamin D levels, and vitamin D receptor expression in granulosa cells on laboratory outcomes of <italic>in vitro</italic> fertilization/intracytoplasmic sperm injection. The study included 206 women with or without thyroid autoimmunity undergoing <italic>in vitro</italic> fertilization/intracytoplasmic sperm injection ovarian stimulation cycles. The primary outcomes in thyroid autoimmunity and non-thyroid autoimmunity patients with high or low follicular fluid vitamin D levels (high vitamin D level, ≥20 ng/mL; low vitamin D level, &lt;20 ng/mL) were the number of oocytes retrieved and quality of embryos. The secondary outcomes were the association between serum and follicular fluid vitamin D levels and vitamin D receptor expression in granulosa cells. Our study revealed that thyroid autoimmunity was associated with fewer good-quality embryos but not oocytes (<italic>p =</italic> 0.010). The vitamin D level in the follicular fluid was significantly correlated with that in the serum (<italic>p</italic> &lt; 0.001, <italic>r</italic> &gt; 0.5). The study populations in the thyroid autoimmunity and non-thyroid autoimmunity groups were divided into two subgroups based on high/low serum/follicular fluid vitamin D levels. There was no significant difference in the number of retrieved oocytes and good-quality embryos between the subgroups with high or low vitamin D levels (<italic>p</italic> &gt; 0.05), and the incidence of thyroid autoimmunity was comparable between the subgroups (<italic>p</italic> &gt; 0.05). Linear regression analysis indicated that thyroid autoimmunity had a negative effect on the number of healthy embryos (<italic>p =</italic> 0.038). Reverse transcription-polymerase chain reaction results indicated that vitamin D receptor expression in granulosa cells was positively correlated with follicular vitamin D levels in the thyroid autoimmunity (<italic>p</italic> = 0.0002) and non-thyroid autoimmunity (<italic>p</italic> &lt; 0.0001) groups. The current findings suggest that thyroid autoimmunity may have a more detrimental effect on <italic>in vitro</italic> fertilization/intracytoplasmic sperm injection laboratory outcomes than vitamin D.</p>