Three-dimensional Versus Two-dimensional Ultrasound Guided Embryo Transfer in Women Undergoing ART Treatment

Objectives: To assess whether embryo transfer guided by three-dimensional ultrasound (3DUS) produces a significantly higher clinical pregnancy rate than embryo transfer guided by two-dimensional ultrasound (2DUS). Hypothesis: 3DUS guided embryo transfer will produce a significantly higher clinical pregnancy rate compared with 2DUS guided embryo transfer. Design and subjects: Prospective randomised control trial (RCT) at the Prince of Wales Hospital. Inclusion criteria include women undergoing embryo transfer in fresh and frozen cycles. Exclusion criteria include women aged \>42 years and women whose endometrial cavity cannot be visualised adequately via US. Power calculations indicate that 232 patients per arm are required to demonstrate an increase of 12% in clinical pregnancy rates. Study instruments: US examinations will be performed using a General Electric(GE) Voluson series US machine with a standard 3D transvaginal probe. For embryo transfer, the Cooks Guardia Access EchoTip catheter will be used. Interventions: 3D versus 2DUS for guidance during embryo transfer. Main outcome measures: clinical pregnancy. Secondary outcome measures: implantation rate, multiple pregnancy, miscarriage, ectopic pregnancy and live birth rates. Data analysis: Data processing and analysis will be performed using the Statistical Packages of Social Sciences for Windows (SPSS, Inc). Descriptive and comparative statistical methods will be used to analyse the primary outcomes. P-values of \<0.05 will be considered significant. Expected results: The study arm undergoing 3DUS guided embryo transfer are expected to have an improved clinical pregnancy rate compared with the control arm undergoing 2DUS guided embryo transfer.