Assessment of leukemia inhibitory factor levels by uterine flushing at the time of egg retrieval does not adversely affect pregnancy rates with in vitro fertilization

Objective To assess intrauterine levels of leukemia inhibitory factor (LIF) by uterine flushing at the time of egg retrieval and to confirm that the procedure has no detrimental effect on pregnancy rates. Design Prospective study. Setting Assisted reproductive unit of a university hospital. Patient(s) Uterine flushing was performed in 148 IVF patients. The first 100 patients were compared with a matched control group. Intervention(s) Uterine flushing at the time of egg retrieval. Main outcome measure(s) IVF-ET results, pregnancy rates, and intrauterine LIF levels. Result(s) Pregnancy rates were not different in the group of patients with (27%) or without uterine flushing (28%). Leukemia inhibitory factor was detected in 60 patients (46%). Pregnancy rates did not differ between patients' detectable LIF and those in whom LIF was undetectable. Mean levels of LIF were 30.1 ± 49.3 pg/mL and 28.6 ± 51.2 pg/mL in pregnant and nonpregnant patients respectively. Conclusion(s) The flushing procedure at the time of egg retrieval did not adversely affect pregnancy rates. Leukemia inhibitory factor was detected in 46% of patients at the time of egg retrieval, but no correlation were observed with better pregnancy rates in patients with detectable LIF. Mean LIF levels did not differ in pregnant and nonpregnant women. Access to endoluminal secretions of the endometrium during IVF-ET may represent a new research in human implantation.