G-CSF for Endometrial Thickness
During implantation, blastocyst attach to endometrium in secretory phase. The relationship between the developing embryo and maternal tissue plays an important role in Successful implantation. Studies show that positional injury in endometrium can increase the rate of implantation and pregnancy due to enormous release of growth factors and cytokines from the site of injury . G-CSF plays an important role in human reproductive achievement. GCSF is a glycoprotein that affects cytokines and growth factors. Immunological mechanisms in the endometrium are involved in the implantation process. GCSF boosts the endogenous cytokines’ secretion and enables various different endocrine routes. Granulocyte-colony stimulating factor binds to a specific receptor expressed on the surfaces of the target cells (such as neutrophils, vascular endothelium, and tro-phoblastic cells) and triggers growth signals within it. It also helps in continuation of pregnancy by temporarily modulating response of T-helper cells (Th-1 andTh-2), which play an important role in immunity, helping medi-ate maternal immune tolerance against the semi-allogenic foetus,which shares some maternal genes, but not all. It is believed that G-CSF has important function in follicular maturation, ovulation, implantation and pregnancy after conception, uterine epithelial cell G-CSF expression remains high for the first few days then due to inhibitory effect of progesterone its levels declines around the time of embryo implantation. In addition, G-CSF concentration in endometrial co-culture correlated with pregnancy luck .
The level of G-CSF in serum and follicular fluid is a prophesier for the success of human IVF. The normal thickness of endometrium is 7 to 14 mm in the secretory phase and it is a prominent factor for successful pregnancy in IVF cycles.
Studies show that pregnancy will not happen if endometrium thickness is less than 6mm .
Furthermore, thin endometrium causes higher risk of miscarriage. One obvious potential explanation for the effects of G-CSF deficiency on pregnancy outcome is a role in targeting leukocytes required for establishing or maintaining pregnancy. Traditional treatment such as low dose aspirin, vaginal sildenafil, pentoxifylline, tocopherol, and estrogen administration are widely inefficient.Only 0.6%-0.8% patients do not reach to the minimum thickness of the endometrium . Moreover, clinician suggest that the IVF cycle should be canceled and all the embryos should be cryopreservated, however, in future cycles there is merely a probability of reaching to the sufficient endometrium thickness. In the other way, clinician would transfer the embryo even though; the chance of pregnancy might decrease. In the present survey, we describe the impact of G-CSF infusion on unresponsive thin endometrium and ART outcome.
Methods: G-CSF (300 microgram/1mL) to improve endometrial thickness was direct administered by slow intrauterine infusion using IUI catheter. If the endometrium had not reached at least a 7-mm within 48-72 h, a second infusion was given. Endometrial thickness was assessed by serial vaginal ultrasound at the most expanded area of the endometrial stripe. After 5 days of G-CSF again endometrial thickness was evaluated(before Embryo transfer).