The associated factors to endometrial cavity fluid and the relevant impact on the IVF-ET outcome

BACKGROUND Endometrial cavity fluid (ECF) is a fluid accumulation within the endometrial cavity. The significance of ECF remains unclear during the program of in vitro fertilization-embryo transfer (IVF-ET). The aim of the present study was to investigate the associated factors to ECF, visualized through ultrasound at the day of oocyte retrieval, and the relevant impact on the outcome of IVF-ET. METHODS From the clinical data of 1557 infertility patients for IVF-ET program, 46 ECF patients were retrospectively selected as the ECF group; and another 134 patients with a bilateral salpingectomy and without ECF, selected as the control group. The demographics and the outcome of IVF-ET were compared between the two groups. RESULTS The incidence of ECF was 2.95% (46/1557). Over half (28/46, 60.87%) of ECF patients had tubal infertility. Only 12 Of 46 ECF patients (26.09%) had visible hydrosalpinx on ultrasonography before ovarian stimulation. The cycle cancellation rate (4/46, 8.69%) of ECF group was not significantly higher than that of the control group (6/134, 4.48%; P > 0.05). Reasons for cycle cancellation in both groups were all the high risk of ovarian hyperstimulation syndrome (OHSS). No significant difference was found in clinical pregnancy rate between the patients with their ECF <3.5 mm in the anterior-posterior diameter (APD) and the control group (35.48% versus 30.47%; P > 0.05). No clinical pregnancy was found among those patients with their ECF equal or higher 3.5 mm in APD. CONCLUSIONS It was tubal infertility, not hydrosalpinx, which was related to the development of ECF. Excessive ECF (equal or higher 3.5 mm in APD) at the day of oocyte retrieval would have a negative impact on the outcome of IVF-ET.