Scholarlink

Background <p>The process of in vitro fertilization-embryo transfer (IVF-ET) induces a maternal supraphysiological estradiol environment during embryo implantation and early development. Estrogen is crucial in modulating the colonization of microbiota within the vaginal epithelium. However, the impact of supraphysiological estradiol levels on the vaginal microbiome and the relationship with pregnancy outcomes remains unclear.</p> Results <p>The study aimed to characterize the vaginal microbiota under supraphysiological hormonal conditions. A total of 67 patients undergoing fresh embryo transfer were divided into three groups based on their peak estradiol levels: high-estradiol (HE) group (E<sub>2</sub> &gt; 11,000 pmol/L), median-estradiol (ME) group (E<sub>2</sub> 5,000–11,000 pmol/L), and low-estradiol (LE) group (E<sub>2</sub> &lt; 5,000 pmol/L). Twenty-five patients undergoing frozen-thawed embryo transfer were categorized into natural cycle (NC) group and hormone replacement cycle (HRT) group according to endometrial preparation protocols. Using 16S rRNA sequencing, we found that the vaginal microbiome exhibited variations with changes in peak estradiol levels. The elevated estradiol levels during ovarian stimulation or exogenous estrogen supplementation, significantly reduced alpha diversity, altered beta diversity within the vaginal microbiome, and shifted the vaginal community state types (CSTs) in Chinese infertile women toward <i>Lactobacillus</i>-dominant profiles, resembling those observed in most Asian women previously. However, the reproductive outcomes were not improved by these variations. The <i>Streptococcus_anginosus</i> and <i>Akkermansia</i> abundance correlated with estradiol levels positively, whereas <i>Escherichia-Shigella</i> showed a negative correlation. The abundance of <i>Streptococcus</i>, <i>Atopobium</i>, and <i>Bifidobacterium</i> on the day of embryo transfer may serve as predictors for adverse pregnancy outcomes, as determined by calculating the area under the curve (AUC) values.</p> Conclusions <p>Supraphysiological estradiol levels induced by IVF-ET significantly alter vaginal microbiota and shift the CSTs in Chinese infertile women toward patterns of most Asian women. The <i>Lactobacillus</i> dominance under supraphysiological estradiol conditions does not help improve assisted reproductive outcomes. The abundance of <i>Streptococcus</i>, <i>Atopobium</i>, and <i>Bifidobacterium</i> on the day of embryo transfer may serve as predictors for adverse pregnancy outcomes. Among them, <i>Streptococcus</i> correlates positively with peak estradiol levels and may act as a microbial mediator impairing reproductive success under hyperestrogenic conditions. However, further larger-scale researches are needed to identify and elucidate the potential mechanisms.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Vaginal microbiota alterations under supraphysiological estradiol state during in vitro fertilization-embryo transfer (IVF-ET) and the association with reproductive outcomes

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2025年8月12日

查看全文
  • Xijing Chen,
  • Feng Chen,
  • Shufang Wu,
  • Pingping Lv,
  • Ping Li

摘要

Background

The process of in vitro fertilization-embryo transfer (IVF-ET) induces a maternal supraphysiological estradiol environment during embryo implantation and early development. Estrogen is crucial in modulating the colonization of microbiota within the vaginal epithelium. However, the impact of supraphysiological estradiol levels on the vaginal microbiome and the relationship with pregnancy outcomes remains unclear.

Results

The study aimed to characterize the vaginal microbiota under supraphysiological hormonal conditions. A total of 67 patients undergoing fresh embryo transfer were divided into three groups based on their peak estradiol levels: high-estradiol (HE) group (E2 > 11,000 pmol/L), median-estradiol (ME) group (E2 5,000–11,000 pmol/L), and low-estradiol (LE) group (E2 < 5,000 pmol/L). Twenty-five patients undergoing frozen-thawed embryo transfer were categorized into natural cycle (NC) group and hormone replacement cycle (HRT) group according to endometrial preparation protocols. Using 16S rRNA sequencing, we found that the vaginal microbiome exhibited variations with changes in peak estradiol levels. The elevated estradiol levels during ovarian stimulation or exogenous estrogen supplementation, significantly reduced alpha diversity, altered beta diversity within the vaginal microbiome, and shifted the vaginal community state types (CSTs) in Chinese infertile women toward Lactobacillus-dominant profiles, resembling those observed in most Asian women previously. However, the reproductive outcomes were not improved by these variations. The Streptococcus_anginosus and Akkermansia abundance correlated with estradiol levels positively, whereas Escherichia-Shigella showed a negative correlation. The abundance of Streptococcus, Atopobium, and Bifidobacterium on the day of embryo transfer may serve as predictors for adverse pregnancy outcomes, as determined by calculating the area under the curve (AUC) values.

Conclusions

Supraphysiological estradiol levels induced by IVF-ET significantly alter vaginal microbiota and shift the CSTs in Chinese infertile women toward patterns of most Asian women. The Lactobacillus dominance under supraphysiological estradiol conditions does not help improve assisted reproductive outcomes. The abundance of Streptococcus, Atopobium, and Bifidobacterium on the day of embryo transfer may serve as predictors for adverse pregnancy outcomes. Among them, Streptococcus correlates positively with peak estradiol levels and may act as a microbial mediator impairing reproductive success under hyperestrogenic conditions. However, further larger-scale researches are needed to identify and elucidate the potential mechanisms.