P-524: Pregnancy outcome in patients undergoing uterine evaluation by saline infusion sonography (SIS) before a frozen embryo transfer (FET) cycle

Abstract

1.3 % of the patients undergoing IVF-FET have structural abnormalities of the uterus & the live birth rate in this group is 27.3%. Uterine anomalies may be associated with implantation failure & early pregnancy loss (PL) & their accurate identification followed by surgical repair can reduce the chances of a negative pregnancy outcome. SIS has been shown to be as reliable as hysteroscopy in uterine evaluation & is more accurate than hysterosalpingography. This study aims to determine the pregnancy outcome in patients who had uterine evaluation by SIS prior to the FET cycle. IRB approved retrospective data analysis. Evaluation of the uterine cavity was done by SIS in 31 patients undergoing FET cycles between September 2005 & April 2006. All patients had a normal uterine evaluation in the past using either SIS or hysterosalpingography before their IVF-ET cycle. Transvaginal sonography was performed followed by SIS in the follicular phase of the menstrual cycle prior to the actual FET cycle. The medical records of the patients were screened for SIS findings & pregnancy outcome. 8/31 patients (25.8%) had a positive finding on SIS. Positive findings on SIS included uterine septum (12.5%), endometrial polyp (37.5%), intramural fibroid, 1 cm, with normal endometrial cavity (12.5%), cystic endometrial changes with negative doppler findings (12.5%) & cervical stenosis (25%). 1 patient with cervical stenosis, had easy cervical dilatation at the time of SIS while the other required dilatation under anesthesia. SIS could not be carried out in her in spite of proper catheter insertion. Hysteroscopy revealed the presence of a false blind passage & intrauterine adhesions, which were subsequently lysed. Operative hysteroscopy was done in 4 patients for the correction of their anomalies. 1 patient with a uterine septum detected on SIS, who declined hysteroscopic treatment, had pregnancy loss at 7 weeks. Missed abortion occurred in the patient with an intramural fibroid for which no treatment was offered. Patients were divided in 3 groups, group A consisted of patients with positive SIS findings & treated, group B consisted of those with positive SIS findings & not treated & group C with negative SIS findings. The mean age, infertility diagnosis, number & grade of embryos transferred (ET) on day 3 were comparable in all the groups. Patients in group A had biochemical pregnancy (BP) & clinical pregnancy (CP) rates similar to group C patients. (Table 1)Table 1Patient characteristics & pregnancy outcomes* 2 results not known because of recent FET * 2 results not known because of recent FET SIS accurately detects structural uterine anomalies prior to FET cycle in cases where time since uterine evaluation has been ≥ 2 years. Subsequent correction of the anomalies may bring the pregnancy rates of the treated patients equivalent to that of the normal group. Though intramural fibroids > 2 cm decrease the chances of an ongoing pregnancy by half, the impact of smaller intramural fibroids remains unclear.