The Female Fertility Cycle
Hormones are natural chemicals that carry messages to our organs. These messages tell organs what to do. All of this hormonal activity causes changes, for women, in the ovary, uterus, and cervical mucus. The female hormonal, or reproductive, cycle can be divided into four main phases:
Phase I - The Menstrual Phase
- When menstrual flow occurs. The first day of flow is called "day one" of the menstrual cycle.
- Menstrual flow consists of blood, cervical and vaginal mucus and the uterus lining.
- Estrogen and progesterone levels are low.
- Several follicles containing eggs begin to ripen.
Phase II - Pre-Ovulatory Phase
- The uterine lining rebuilds.
- Follicles continue to ripen and produce estrogen -mid cycle one follicle undergoes a growth spurt, the others shrink and die.
Phase III - Ovulation
- Occurs about the 14th day from the start of the next period (approx mid-cycle in a 28 day cycle).
- When the follicle has matured, hormonal messages are sent to the ovary which causes the ovarian follicle to rupture.
Phase IV - Post-Ovulation
- Estrogen is produced by the remnants of the burst follicle.
- Progesterone is also produced to stimulate the uterus to produce food for the uterine lining so a fertilized egg could implant.
- As the uterus is being prepared the cilia of the fallopian tubes create a current to draw in the egg.
- Once the egg is drawn in it takes about four days to travel through the tube and into the uterus.
- If the egg is fertilized it will attempt to implant into the nourishing uterine lining.
- If the egg is not fertilized, hormone levels drop and cause the uterine lining to begin to shed, beginning a new cycle.