Granulocyte colony-stimulating factor for recurrent implantation failure: the results of a 5-years cohort study

Despite the significant progress in the management of infertility, recurrent implantation failure (RIF) is yet a challenge for infertility physicians. It has a deep financial and psychological impact on RIF patients. Granulocyte-colony stimulating factor (G-CSF) has emerged as a chemical that can increase embryo implantation and clinical pregnancy rates in patients with RIF. This ambispective observational cohort study was carried out at the IVF unit of Cairo University Kasr Alainy Obstetrics and Gynaecology Hospital between October 2019 and September 2024. All RIF patients who underwent fresh embryo transfer (ET) from 10/2019 to 9/2023 were treated with intrauterine (IU) infusion of G-CSF after oocyte pick-up and during the mock ET test, three days before fresh ET. The outcomes of RIF patients who had fresh ET before and after these dates were recorded and used as the control group. We excluded patients who were very old in age (> 42 years old) as well as those who had significant uterine, immunological or genetic factors that might affect implantation. We analyzed 40 patients in the study group and 39 in the control group. The study group had higher IU clinical pregnancy (27.5% vs. 17.9%) and chemical pregnancy rates (35% vs. 23%), but neither was statistically significant (P = 0.28 and P = 0.243, respectively). The implantation rate was significantly higher in the study group (0.33 ± 0.25 vs. 0.33 ± 0.08, P = 0.04). First-trimester abortion was lower in the study group (18.2% vs. 42.9%), but not statistically significant (P = 0.25). Endometrial thickness increased by 1.15 ± 1.5 cm in the study group; data for this variable in the control group were poorly documented. IU G-CSF administration in idiopathic RIF patients before undergoing fresh ET improved implantation rates, while it did not alter clinical or chemical pregnancy or first-trimester abortion rates.Trial registration: This study was registered with the identifier NCT04998279 on 26/7/2021 in the National Library of Medicine registry (clinicaltrials.gov).