Impact of "non-physician factors" on the "physician factor" of in vitro fertilization success: is it the broth, the cooks, or the statistics?

Predictive value of the time interval between embryo loading and transfer for IVF/ICSI success: a prospective cohort study

BACKGROUND

The influence of embryo loading time (ELT) and the time interval between embryo loading and embryo transfer (TIEL-ET) on the success of IVF/ICSI is unknown.

METHODS

In a prospective cohort study, we aimed to ascertain the influence of ELT and TIEL-ET on ongoing pregnancy rate (OPR) and life birth rate (LBR). Data from 603 consecutive embryo transfers between January 2008 and December 2013 were collected. A complete data set including the outcomes of interest OPR and LBR was available for 410 women. The primary outcome was IVF/ICSI success, defined as OPR and LBR.

RESULTS

We used univariate and multivariate logistic regression for analysis. In a multivariate analysis, age (odds ratio [OR] 0.94; 95% confidence interval [CI] 0.89-0.99), catheter type (OR 0.45; 95% CI 0.24-0.84), and uterine length (OR 1.03; 95% CI 1.01-1.06), but not ELT and TIELT-ET were independently associated with OPR. Regarding LBR, age (OR 0.93; 95% CI 0.88-0.98), catheter type (OR 0.41; 95% CI 0.22-0.79), and uterine length (OR 1.03; 95% CI 1.01-1.06), but not ELT and TIELT-ET were independent predictors.

CONCLUSION

We conclude that speed of embryo transfer is not critical for the success of IVF/ICSI. However, care should be taken to choose catheter types proven to be associated with a high success rate.

The impact of the embryo transfer catheter on the pregnancy rate in IVF

BACKGROUND

The aim was to assess whether the type of embryo transfer set used for embryo transfer affects the ongoing pregnancy rate in IVF.

METHODS

The TDT set was compared with the K-soft 5000 in a large, prospective, randomized study. Patients were randomized moments before transfer by drawing a consecutively numbered, sealed, opaque envelope indicating the catheter to be used.

RESULTS

2059 embryo transfers in 1296 patients were analysed. The ongoing pregnancy rate was significantly higher in the K-soft group. If the first transfer of a patient (n = 1296) within this study period was analysed, the ongoing pregnancy rates were 27.1 versus 20.5% (P = 0.006). If the analysis is limited to patients that underwent their very first transfer ever (n = 607), the ongoing pregnancy rates were 30.3 versus 20.0% (P = 0.003) in favour of the K-soft.

CONCLUSION

We conclude from these data that the type of embryo transfer set used for embryo transfer does affect the ongoing pregnancy rate and that the impact of the variable transfer catheter on the ongoing pregnancy rate increases when the a priori chance of pregnancy increases.