Imaging of female infertility

The female reproductive tract includes the vagina, uterus and cervix, fallopian tubes, and ovaries and the hypothalamus and pituitary, breasts, and their supporting structures. For the discussion of infertility, the article focuses on the structures of the female pelvis and the monthly physiologic changes that allow conception to occur and are reflected in anatomic changes that can be imaged. The hypothalamus in the female controls the monthly cycling of hormones responsible for normal ovulation and the readying of the endometrium for embryo implantation. Releasing factors from the hypothalamus stimulate production and release of the anterior pituitary gonadotropins, follicle-stimulating hormone, and luteinizing hormone. Follicle-stimulating hormone and luteinizing hormone cause maturation of ovarian follicles signaled by increase in follicular fluid and follicular estrogen production. The increasing estrogen results in a surge of leuteinizing hormone , which in turn causes rupture of one follicle and expulsion of its ovum, which can then be swept into the fimbriated end of the fallopian tube. The ruptured follicle develops into a corpus luteum, which produces progesterone and estrogen and has a life span of approximately 12 to 13 days. Estrogen and progesterone stimulate growth and development of the secretory endometrium. The follicles that developed, but were not ovulated, become atretic. Sperm are deposited in the vagina and travel up the cervix and uterus into the fallopian tube. Fertilization of the ovum occurs in the ampullary portion of the fallopian tube. As the embryo begins to develop, it travels down the fallopian tube and into the uterine fundus, where it implants in the endometrium. If conception does not occur, the corpus luteum regresses and its hormones are withdrawn, which results in endometrial shedding (menstruation). The cycle is repeated every month, with an average duration of 28 days for the follicular, secretory, and regression phases.