Subendometrial–myometrial contractility in conception and non‐conception embryo transfer cycles

This study describes the characteristics of subendometrial–myometrial contractions seen on transvaginal sonography on the day of embryo transfer in assisted conception cycles and their significance for pregnancy outcome. A total of 112 cycles were studied where three embryos with minimal or no fragmentation were transferred. Transvaginal sonography was performed just prior to embryo transfer. A sagittal view of the uterine cavity was obtained and the ultrasound probe was held steady for 2 min. The video recorded image was analyzed at normal, three and five times normal speed. The frequency (contractions/min), direction (fundally or cervically directed) and length (entire cavity or localized) of contractions were noted. Conception and non-conception cycles were compared by determining the standard error of difference between means and proportions and the confidence intervals. The mean frequencies of contractions in the conception and non-conception cycles were 2.09 (SD = 0.8) and 1.92 (SD = 0.85), respectively. A total of 57.6% of cycles in the conception group and 46% in the non-conception group had contractions directed towards the cervix. There was no statistically significant difference between the two groups in any of the parameters studied. However, when frozen embryo replacement cycles (n = 40) were studied separately, the incidences of fundally directed contractions were 28.6% and 66.7% in conception and non-conception cycles, respectively. This was statistically significant. Comparison of cycles resulting in miscarriage with those leading to pregnancies beyond 16 weeks revealed no statistical difference in the characteristics of the contractions. We concluded that subendometrial–myometrial contractions studied on the day of embryo transfer (luteal day 2) do not predict the outcome in in vitro fertilization cycles. Copyright © 1994 International Society of Ultrasound in Obstetrics and Gynecology