Is uterine depth measurement by trans-vaginal ultrasound alone as accurate as measurement carried out by trans-abdominal ultrasound-guided trial transfer?

ABSTRACT

To assess the reliability of trans-vaginal-scan [TVS] in measuring the uterine depth [UD] in comparison with ultrasound-guided trial-transfer [UTT]. This prospective study was conducted in 66 consecutive patients undergoing in-vitro fertilization and embryo transfer [IVF-ET]. The study took place in a private IVF center in Jeddah, Saudi Arabia between November 2013 and January 2014. The patients underwent UD measurements using TVS and UTT, sequentially. All scans were performed by a single sonographer, and all UTT were carried out by a single physician who was blinded to the TVS measurement. The median [95% confidence interval] UD measurement using the TVS method was 6.9 cm [5.0-12.5] and UTT was 7.1 cm [5.9-13.5], [p<0.0001]. Fifteen patients [22.7%] had a difference of >1 cm between the 2 measurement modalities [group-B]. When measured by UTT, 93.3% of patients in group-B had UD >/= 8 cm, compared with 9.8% of patients in group-A, [p<0.0001]. Group-B had a significantly longer uterine cavity when measured by UTT [p<0.0001], and a trend towards significance when measured by TVS [p=0.055]. The TVS measurements generally underestimated UD when compared with UTT. Trans-vaginal-scan is less reliable than UTT and should not be used as a substitute. Larger sample-size studies involving different personnel, and equipment is needed