Infertility In Women - Introduction

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Highlights	Treatment	References
Introduction	Medications	Resources
Causes	Assisted Reproductive Technologies	References
Risk Factors	Lifestyle Changes
Diagnosis	Resources

The uterus is a hollow muscular organ located in the female pelvis between the bladder and rectum. 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 prior to birth.

Reproductive Hormones. The hypothalamus (an area in the brain) and the pituitary gland regulate the reproductive hormones.

Click the icon to see an image of the hypothalamus and pituitary gland.

The pituitary gland is often referred to as the master gland because of its important role in many vital functions, many of which require hormones. In women, six key hormones serve as chemical messengers that regulate the reproductive system:

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The hypothalamus first releases the gonadotropin-releasing hormone (GnRH).
This chemical, in turn, stimulates the pituitary gland to produce follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

Click the icon to see an image of the pituitary gland.

Estrogen, progesterone, and the male hormone testosterone are secreted by the ovaries at the command of FSH and LH and complete the hormonal group necessary for reproductive health.

Ovulation. The process leading to fertility is very intricate. It depends on 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. Nevertheless, this process results in conception within a year for about 80% of couples. Only 15% conceive within a month of their first attempts, however, and about 60% succeed after 6 months.

A woman's ability to produce children occurs after she enters puberty and begins to menstruate. The process of conception is complex:

With the start of each menstrual cycle, follicle-stimulating hormone (FSH) stimulates several follicles to mature over a 2-week period until their eggs nearly triple in size. Only one follicle becomes dominant, however, during a cycle.
FSH signals this dominant follicle to produce estrogen, which enters the bloodstream and reaches the uterus. There, estrogen stimulates the cells in the uterine lining to reproduce, therefore thickening the walls.
Estrogen levels reach their peak around the 14th day of the cycle (counting days beginning with the first day of a period). At that time, they trigger a surge of luteinizing hormone (LH).