ABSTRACT
OBJECTIVE: To present a modified transvaginal ultrasound (TVUS) guided embryo transfer (ET) procedure and analyze its efficacy in comparison with conventional transabdominal ultrasound (TAUS) guided ET in an unselected population of Brazilian women. METHODS: This retrospective observational case-control study involved 447 fresh ET cycles, 221 guided by TVUS (Group 1), conducted between June 2016 and February 2019, and 226 by TAUS (Group 2), conducted between July 2012 and December 2015. Pregnancy rate was the main endpoint. Groups were compared using the Z test at a level of significance of 95% (p≤0.05). RESULTS: Patient age ranged from 21 and 48 years; mean age was 37.7 years in Group 1 and 38 years in Group 2. Overall, patients that underwent TVUS-guided fresh ET demonstrated significantly higher pregnancy rates than their counterparts that underwent TAUS-guided fresh ET (p=0.0107). TVUS-guided fresh ET also yielded significantly higher pregnancy rates in the subgroups of women aged 36-39 years (p=0.0037) and ≥ 40 years (p=0.0025). However, no significant pregnancy rate difference was observed in women aged ≤ 35 years (p=0.0905). CONCLUSIONS: The results suggested that TVUS-guided fresh ET was at least as effective as TAUS-guided fresh ET in the studied sample. Pending further prospective studies to better ascertain the effect of TVUS-guided ET, the technique presented deserves consideration since it can offer better visualization, more comfort to patients, and requires only one operator, without negatively affecting pregnancy results.