Follicle 18*16mm intercourse will not affect the growth of the follicle, it is already a dominant follicle, you need to ensure that every other day sexual intercourse, further ultrasound to monitor the follicle. When the follicle reaches about 18-23mm, it belongs to the dominant follicle, and there is a chance of ovulation at any time. So you need to make sure that you have sex every other day and that the follicles are ready to ovulate at any time. You need to continue to monitor the follicle, if the follicle reaches 25mm and still no ovulation, clinically known as follicular luteinization, may be due to the follicle wall is too thick, insufficient pressure inside the follicle, insufficient hormone levels, etc., the use of egg-breaking injections to treat the necessary. Follicle 18*16mm although intercourse does not affect the follicle growth, need to continue to monitor the follicle, by the doctor according to the specific circumstances, to formulate individualized diagnosis and treatment plan.