 Accurate assessment of the size of follicles is important in IVF treatment.Timing of oocyte maturation and subsequent egg collection is largely based on follicle size. An accurate assessment of follicle size and appropriate timing of HCG result in retrieval of more mature oocytes, improved fertilization and higher pregnancy rates. in 3D technology- fter the capturing of a 3D image of an ovary, SonoAVC automatically analyzes the volume dataset, identifies the boundaries of hypoechoic follicles, and provides estimates of their absolute dimensions. These measurements include the largest diameters in three orthogonal planes, the mean follicular diameter MFD, the volume of the follicle, and the volume-based diameter dV of the follicle. In the current study the investigators aim to evaluate the use of this automated technique of follicle measurement vs. standard 2D technology on the timing of oocyte maturation and subsequent oocyte retrieval. The investigators speculate that 3D assessment will increase the rate of mature oocyte collection, and eventually will improve other treatment outcomes such as fertilization rate. 