Bilateral ovulation is also known as ovulation on both sides of the ovaries. The chances of ovulation on both sides of the ovaries are relatively small and there is no specific value. The ovaries are located on both sides of the uterus, the right and left ovaries respectively. Most women ovulate alternately between the right and left ovaries during ovulation, for example, the left ovary ovulates in the first month, and the right ovary ovulates in the second month, but it is not absolute. Sometimes, it is possible to have the same ovary ovulating for two consecutive months or a few months, or for the two ovaries ovulating at the same time, or for the two ovaries ovulating at the same time, or for the two ovaries ovulating at the same time, but not at the same time. The chances of ovulation on both sides of the ovary are relatively small, the exact probability is not clear, usually one follicle shrinks on its own, and one follicle matures and is expelled. Women who want to know exactly which side of the ovaries ovulate each month can be monitored by ultrasound before and after ovulation to determine which side of the ovaries ovulate, and also to observe follicular development and ovulation.