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Updated: Jul 6, 2026
Isolation of Human Endometrial Stromal Cells for In Vitro Decidualization
Published on: September 1, 2018
Endometrial inhibin/activin beta-B subunit expression is related to decidualization and is reduced in tubal ectopic
A W Horne1, S van den Driesche, A E King
1Obstetrics and Gynaecology, University of Edinburgh, Simpson Centre for Reproductive Health, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, United Kingdom. andrew.horne@ed.ac.uk
Context:
Ectopic pregnancy is common but remains difficult to diagnose accurately. There is no serum test to differentiate ectopic from intrauterine gestation.
Objective:
Our objective was to investigate differential gene expression in decidualized endometrium of ectopic pregnancy.
Design:
Tissue and serum analysis informed by microarray study was performed.
Setting:
The study was performed at a large United Kingdom teaching hospital.
Patients Or Other Participants:
Women undergoing surgical termination of pregnancy (n = 8), evacuation of uterus for miscarriage (n = 6), and surgery for tubal ectopic pregnancy (n = 11) were included in the study. Endometrium was collected from normally cycling women undergoing hysterectomy.
Interventions:
Decidualized endometrium was subjected to microarray analysis, morphological assessment, and immunohistochemistry. Endometrial stromal fibroblasts were cultured in the presence of decidualizing stimuli.
Main Outcome Measures:
Differential expression of potentially secreted molecules was calculated.
Results:
Inhibin/activin beta-B expression was lower in decidualized endometrium from ectopic pregnancies when compared with that of ongoing pregnancies (P < 0.01) or miscarriages (P < 0.01). The localization of the beta-B subunit was more marked in decidualized than nondecidualized stroma. Decidualization of stromal fibroblasts in vitro was associated with increased beta-B expression (P < 0.05). Endometrial stroma of ectopic pregnancies was less decidualized morphologically (P < 0.05), with lower prolactin (P < 0.01) and IGF binding protein-1 (P < 0.005) expression. Serum activin B was lower in ectopic pregnancies (P < 0.005) than in intrauterine pregnancies, whereas there was no difference in progesterone concentrations.
Conclusions:
Despite similar concentrations of progesterone, the endometrium of ectopic pregnancies is less decidualized than intrauterine pregnancies. Expression of the beta-B subunit is related to decidualization and can be detected in the circulation as activin B. Serum activin B concentrations are lower in ectopic pregnancy.
