During ovulation, a mature egg is released from one of the ovaries. The egg is then released and travels into the fallopian tube, where it may be fertilized by a sperm cell. The hormone that is at its peak during ovulation is luteinizing hormone (LH). LH is quickly released when estrogen levels are high enough to cause it. This normally occurs on or around cycle day thirteen. LH is responsible for the final maturation of the follicle and triggers ovulation. Luteinizing hormone is generated and secreted in the anterior pituitary gland.