An intrauterine device (IUD) is one of the most effective reversible contraceptive methods currently available. Women who use IUDs may become pregnant, albeit rarely, and many such women continue to use IUDs, because it is difficult to remove, or it may cause miscarriage. However, a recent study suggests that copper IUD may affect embryonic development by regulating the expression of villus Insulin-like growth factor II (IGF-II). The study findings were published in the Growth Hormone & IGF Research in February 2022 issue.
Human leucocyte antigen-G (HLA-G) is highly expressed in trophoblast membranes, reflecting immune tolerance at the maternal-fetal interface. HLA-G polymorphisms are associated with vascular remodelling, early embryonic development, and maintenance of normal pregnancy.
IGF-II is involved in the regulation of several stages of early pregnancy via autocrine, paracrine, and endocrine mechanisms. Reduced IGF-II expression is associated with intrauterine growth restriction, pre-eclampsia, embryonic developmental abnormalities, and embryonic death.
The effect of IUD on IGF-II and HLA-G levels remain understudied. Therefore, Dr Lili Huang and her team conducted a study and measured the IGF-II and HLA-G levels in the decidua and villi to explore the effect of a copper IUD on embryonic development.
In this present study, the researchers used 54 samples of decidual and villus tissue, collected from pregnant women with IUDs (27 samples) or without IUDs (27 samples). They used hematoxylin-eosin staining to identify morphological characteristics and immunohistochemistry to detect HLA-G and IGF-II. They further measured the protein expression levels via Western blotting.
Key findings of the study:
Upon analysis, the researchers observed HLA-G was expressed on the membranes of trophoblasts of villus tissues and the glandular epithelium, and in stromal cells of decidual tissues, in both the IUD and control groups.
They noted that IGF-II was expressed in the glandular epithelium and cytoplasm of trophoblasts and decidual cells in both groups.
Compared to the control group, they found that the IGF-II expression was significantly reduced in villus tissues of the IUD group.
They noted that the mean sac diameter was significantly positively correlated with IGF-II expression in the villi.
The authors concluded, "Copper IUDs had no significant effect on the morphology of decidual or villus tissues. HLA-G was expressed on the membranes of trophoblasts of villus tissues and the glandular epithelium, and in the stromal cells of decidual tissues, in patients with and without IUDs."
They further added, "IGF-II was expressed in the glandular epithelium, and the cytoplasm of trophoblasts and decidual cells, in patients with and without IUDs. Copper IUDs may reduce IGF-II expression in villus tissue, which could compromise embryonic development."
For further information:
DOI: https://doi.org/10.1016/j.ghir.2021.101441