A woman's ability to have children occurs after puberty and begins to menstruate. The uterus is the central part of female reproductive system. The ovaries produce the eggs that travel through the fallopian tubes. Once the egg has left the ovary it can be fertilized and implant itself in the lining of the uterus. The main function of the uterus is to nourish the developing fetus. The process leading to fertility is very intricate. For pregnancy to occur, every part of the complex human reproduction process, from the ovary's release of a mature egg to the fertilization of the egg to the fertilized egg's implantation and growth in the uterus, has to take place which involves the healthy interaction of the reproductive organs and hormone systems in both the male and female.
In addition, reproduction is limited by the phases of female fertility.
The hypothalamus and the pituitary gland regulate the reproductive hormones in females. Six key hormones serve as chemical messengers that regulate the female reproductive system. The hypothalamus releases the gonadotropin-releasing hormone (GnRH) which in turn, stimulates the pituitary gland to produce follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Estrogen, progesterone, and the male hormone testosterone are secreted by the ovaries at the command of FSH and LH and complete the hormones essential for reproductive health.