ACTA ENDOCRINOLOGICA (BUC)

Background. There is no immunohistochemical study to show luteinizing hormone receptor (LHR), estrogen receptor (ER) and progesterone receptor (PR) in the pregnant Fallopian tubes (FT). Objective. To study LHR, ER, PR expression in FT containing an ectopic pregnancy (EP) and during the menstrual phase. Design. Thirty FT were obtained from women diagnosed with EP and twenty FT collected by hysterectomy performed for benign diseases not affecting the tubes were included in this study. Assessment of immunohistochemical expression staining LHR, ER, PR in epithelium, smooth muscle cell and blood vessel endothelium in FT containing an EP and during the different phases of menstrual cycle. Results. In ectopic pregnancy group we found LHR expression in epithelium in 30 cases, muscle cell in 28 cases, and endothelium in 9 cases in FT. In menstrual cycle group we noted LHR expression in FT in epithelium in all cases, muscle cell in 4 cases. Conclusion. There is a significant difference in the proportions of the existence of LH receptor immunostaining in the muscle cells for ectopic pregnancy group as compared to the menstrual cycle groups (p < 0.001). Our findings may suggest that the women who have increased LH receptors on muscle cells in Fallopian tubes are at increased risk for having external pregnancy.