The Role of Combined Treatment of Granulocyte Colony-stimulating Factor and Oestrogen in Treatment of Thin Endometrium: A Rat Model

Background: Thin endometrium, described as endometrial thickness below 7 mm on embryo transfer day in assisted reproduction cycles, is associated with decreased pregnancy rates. Granulocyte colony-stimulating factor (G-CSF) and oestrogen (E) are two medications used for treatment.

Aim: The aim of this study is to demonstrate the effect of combined G-CSF+E treatment on thin endometrium in a rat model.

Settings and design: Gazi University Laboratory Animals Breeding and Experimental Researchers Center provided the veterinary care.

Materials and methods: Forty-eight female rats were divided into 8 groups (6 rats/group). Groups were named as group 1: control, group 2: control that received G-CSF, group 3: control that received E, group 4: control that received G-CSF+E, group 5: thin endometrium model, group 6: thin endometrium model that received G-CSF, group 7: thin endometrium model that received E and group 8: thin endometrium model that received G-CSF+E. Twelve days after the establishment of thin endometrium model, G-CSF and/or E treatment was started and continued for 5 days according to the groups. Tissue specimens were collected at the end of the treatment period. Proliferation, apoptosis and angiogenesis were evaluated.

Statistical analysis used: The data were analysed using one-way analysis of variance and Tamhane post hoc test.

Results: Significant increase in uterine wall and endometrial thickness was detected in the thin endometrium + G-CSF group when compared to the thin endometrium group. G-CSF was demonstrated to cause an extensive proliferative response and induction of angiogenesis in thin endometrium without restoration of endometrial glands. E alone restored thin endometrium to almost normal histology. Morphological changes representing the dominant effects of G-CSF were observed in thin endometrium model receiving G-CSF+E.

Conclusion: G-CSF+E is not an effective treatment modality in thin endometrium rat model.