The outcome of singleton pregnancies after IVF/ICSI in women before and after hysteroscopic resection of a uterine septum compared to normal controls

Objective(s)To evaluate the effect of hysteroscopic resection of a large uterine septum (Class V according to the American Fertility Society (AFS) classification) and of a small partial uterine septum (Class VI according to AFS classification or arcuate uterus) on the abortion rate in pregnancies after IVF and ICSI.Study designThe retrospective matched control study included 31 women who conceived following IVF or ICSI before hysteroscopic resection of a large (12 women) or small partial (19 women) uterine septum and 106 women who conceived following IVF or ICSI after hysteroscopic resection of a large (49 women) or small partial (57 women) uterine septum. For each pregnancy in the study group, we found two consecutive pregnant control women from the IVF/ICSI registry who had a normal uterus and were matched for age, BMI, stimulation protocol and the use of IVF or ICSI and for various infertility causes. The abortion/pregnancy rate was the main outcome measure. Data on the septum length were obtained during hysteroscopic resection by comparing the length of the 1.4 cm long yellow tip of the electric knife to the length of the resected septum.ResultsThe abortion rate before hysteroscopic metroplasty was significantly higher, both in women with a small partial septum (78.9% before resection vs. 23.7% in the normal controls, OR 12.08) and a large septum (83.3% before resection vs. 16.7% in normal controls, OR 25.00) compared to women with a normal uterus. After the surgery, the abortion rate was comparable to the abortion rate in women with normal uterus: in both women with a small partial and women with a larger septum.Conclusion(s)Similar to a large uterine septum, a small partial uterine septum is an important and hysteroscopically preventable risk factor for spontaneous abortion in pregnancies after IVF and ICSI.