Table 5. Degree of transfer difficulty and efficiency parameters over time for the semi-rigid catheter
  Quartiles
First (n=90) Second (n=90) Third (n=90) Fourth (n=93)
Transferred embryos 2.5 ± 0.8 2.8 ± 1.1 2.9 ± 1.0 2.7 ± 0.9
Blood after ET 8/90 (8.9%) 7/90 (7.8%) 9/90 (10.0%) 12/93 (12.9%)
Use of a tenaculum 22/90 (24.4%) 20/90 (22.2%) 14/90 (15.6%) 16/93 (17.2%)
Use of a hysterometer 3/90 (3.3%) 5/90 (5.6%) 4/90 (4.4%) 6/93 (6.5%)
US guidance required 8/90 (8.9%) 10/90 (11.1%) 8/90 (8.9%) 6/93 (6.5%)
Embryos retained in catheter 1/90 (1.1%) 2/90 (2.2%) 5/90 (5.6%) 4/93 (4.3%)
Implantation rate 30/238 (12.6%) 31/241 (12.9%) 25/230 (10.9%) 39/253 (15.4%)
Clinical pregnancy rate 25/90 (27.8%) 20/90 (22.2%) 24/90 (26.7%) 24/93 (25.8%)
Miscarriage 3/25 (12.0%) 3/20 (15.0%) 4/24 (16.7%) 6/24 (25.0%)
Ectopic pregnancy 0/25 (0%) 1/20 (5.0%) 1/24 (4.2%) 0/24 (0%)
Take home baby rate 22/90 (24.4%) 16/90 (17.8%) 19/90 (21.1%) 18/93 (19.4%)