A uterine sister is a woman who shares the same mother but has a different father. This means they are half-sisters, related only through their maternal lineage.
Understanding Uterine Sisterhood
The term "uterine sister" specifically highlights the shared maternal connection. While the term "half-sister" is more commonly used, "uterine sister" emphasizes the biological relationship through the mother's side. This distinction is particularly relevant in legal and genealogical contexts.
Several studies have used the term "Sister Study" in research on uterine cancer risk factors. These studies, as seen in various NIH publications (https://www.nih.gov/news-events/news-releases/hair-straightening-chemicals-associated-higher-uterine-cancer-risk, https://pubmed.ncbi.nlm.nih.gov/38346713/, https://nihrecord.nih.gov/2023/01/06/study-finds-hair-straightening-chemicals-raised-uterine-cancer-risk, https://pubmed.ncbi.nlm.nih.gov/36245087/, https://dx.doi.org/10.1093/jnci/djae031), involved large numbers of women to explore connections between various factors (such as hair straightening chemicals and air pollution) and uterine cancer risk. While the studies use "Sister Study" as a title, their use does not directly define what a uterine sister is, but rather utilizes the term to broadly describe the participants in a study of related females.
Note: The term "uterine sister" should not be confused with medical terminology relating to the uterus, such as a "Sister-U" training model (https://shop.laerdalglobalhealth.com/product/sister-u/) used for medical training.
