Heated and Non Heated Ovarian Aspiration Needle Protocol

The estimated sample was 600 oocytes for each group, totaling a minimum of 1200 oocytes, considering a fertilization rate of 65% in the control group and 73% in the study group, for a power of 80% and p alpha 5%, i.e. , an increase of more than 10% between groups. As there is no data in the literature, when the investigators have this sample an interim analysis to evaluate the data will be performed. The investigators consider 10% a reasonable difference that can (with this sample size) increase by 48 embryos and a possible increase of 7 pregnancies within this sample. Bearing in mind that the average number of oocytes retrieved per patient is 6 oocytes, the investigators estimate that 200 patients will be needed to reach the calculated sample number.

The warm-up protocol will be applied by the embryologists, which consists of heating the follicular aspiration needle to 37 Celsius, overnight, the day before the day of the ovarian aspiration procedure.

The variables that will be compared between the studied groups are the rates of oocyte retrieval, maturity (MII), fracture, atresia, fertilization rates and discarded embryos.

Continuous variables will be analyzed using Student's t test if they have normal distribution, for comparison of means between two independent groups or the Wilcoxon-Mann-Whitney U test if not parametric. Differences between groups will be considered significant when p<0.05.

Inclusion criteria

• All women submitted to IVF cycles

Exclusion criteria

• Women submitted to follicular aspiration due to oocyte cryopreservation
• Patients without oocyte retrieved
• Patients without mature oocyte retrieved
• Procedures with needle replacement