[Endometrial thickness in in vitro fertilization. A study of 414 cases].

Background: Study of endometrial thickness is central to the monitoring of ovulation in in vitro fecondation (IVF). Actually, failures of in vitro fecundation are mainly due to implantation failure of embryo.

Aims: • To assess whether the endometrial thickness the day of the induction of ovulation influences or not the result of the IVF attempt. • To determine the endometrial thickness for which the chances of pregnancy are the highest. • To determine if there is any effect of the stimulation protocol or the gonadotrophin on the endometrial thickness.

Methods: A retrospective study at the Reproductive Medicine-Unit of Farhat Hached teaching hospital, Sousse-Tunisia, concerning all the cases of IVF conducted the year 2008.

Results: A total of 414 cycles of IVF were studied. The rate of pregnancies in our series was 23%. There was not statistically significant relation-ship between the women's-age and the endometrial thickness; nor between the rate of the ?stradiol before the IVF trial and the endometrial thickness. The endometrial thickness after ovarian stimulation was significantly linked to the rate of FSH before the IVF attempt (P=0.01). The total rate of pregnancies was significantly linked to the endometrial thickness before the ovulation induction (P=0.02). The best rate of pregnancy was reached with an endometrial thickness>2 mm (43%) and the chances of success in that case were roughly 3 times higher than if the endometrial thickness was ≤12 mm. With ICSI (277 cases), there was a statistically significant relation-ship between endometrial thickness and the pregnancy-rate (P=0.009). There was a statistically significant relation-ship between the endometrial thickness and the stimulation protocol used (P<0.001) and no statistically significant relation-ship between endometrial thickness and the gonadotrophin used for ovarian stimulation (hMG or recombinant FSH).

Conclusion: There is a statistically significant relation-ship between the endometrial thickness and the success rate of ICSI attempt. A thickness higher than 12 mm seems to improve IVF results.