Women often welcome the idea of menopause. They embrace a life free of the hassles caused by menstruation, the monthly period. Younger women are experimenting with birth control medications that reduce the occurrence of menstruation to every three months or stop it indefinitely. While the idea of living without maxi pads and tampons and blood-stained clothes and sheets is enticing, women should think twice about the benefits of having that monthly period. The absence of a period is called amenorrhea, and it can be a sign of a more serious problem.
Primary Amenorrhea
Women who have not begun menstruating by the age of 16 have primary amenorrhea. The cause may be due to one of several rare conditions. During fetal development, the uterus or ovaries may not develop normally or at all. The vagina may develop without an opening, so blood cannot flow from the uterus to produce visible signs of menstruation. Chromosomal abnormalities may significantly reduce the number of eggs and follicles present.
The pituitary gland sits at the base of the brain and is an important organ in hormonal regulation. Early in the menstrual cycle, it releases follicle-stimulating hormone (FSH). In the first half of the menstrual cycle, FSH stimulates the ovarian dominant follicle to grow and mature. The pituitary gland also releases luteinizing hormone (LH), which stimulates the dominant follicle to produce estradiol, a type of estrogen that stimulates the inner lining of the uterus, or endometrium, to proliferate in preparation for blastocyst implantation. A blastocyst is a developing embryo shortly after fertilization occurs and during implantation within the uterus. A tumor growth within, or impinging on, the pituitary gland can disrupt the development of the dominant follicle and the glandular endometrium.
The hypothalamus is the portion of the brain lying above the pituitary gland. It releases gonadotropin-releasing hormone (GnRH), which stimulates the pituitary gland to release FSH and LH. Hypothalamic production of GnRH can be disrupted by excessive stress, too much exercise, eating disorders, excessively low weight, or a hypothalamic tumor. If there is no GnRH production, the pituitary cannot release hormones for dominant follicle development, and amenorrhea may result.
Secondary Amenorrhea
Women who begin menstruating may suddenly stop having periods. Pregnancy is a normal cause of secondary amenorrhea. Breast-feeding may prolong amenorrhea, although ovulation may occur and pregnancy is possible.
Hormonal birth control affects women in many different ways. Some may continue having periods at normal intervals. Others may cease having periods. Some birth control medications are designed to reduce menstruation to four times per year, while others cease menstruation altogether. Other types of medication, such as antidepressants and chemotherapy, may also cause amenorrhea.
As described for primary amenorrhea, pituitary and hypothalamic abnormalities may affect hormonal production, ceasing menstruation. Stress, excessive exercise, eating disorders, excessively low weight, or a hypothalamic tumor may inhibit the production of GnRH, which stimulates the pituitary gland to produce FSH and LH. A pituitary tumor may disrupt the production of FSH and LH, inhibiting the development of a dominant follicle and a glandular endometrium. A pituitary tumor may also cause increased prolactin levels, which can inhibit the production of estradiol. Any of these hormonal imbalances may cause amenorrhea.
Uterine surgical procedures, such as caesarean section, dilation and curettage (D&C), endometrial ablation, and tumor removal, can result in the development of scar tissue within the uterine cavity. This scar tissue can inhibit the normal development of the endometrial lining producing light periods or amenorrhea.
Polycystic ovarian syndrome (PCOS) produces estrogen and androgen levels that remain high throughout the menstrual cycle. Androgens are hormones that are responsible for male sex characteristics, although lower levels are necessary for normal function within the female body. High estrogen levels inhibit the pituitary gland from secreting FSH and LH. With PCOS, this prevents a dominant follicle from developing, and may result in amenorrhea.
Hypothyroidism is the low circulation of thyroid hormone throughout the body. The pituitary releases FSH to stimulate the thyroid to produce more thyroid hormone. Therefore, hypothyroidism can result in sustained, elevated levels of FSH, which can prevent ovulation. If FSH levels are elevated, and estrogen levels are low, a diagnosis of premature ovarian failure may be made.
The diagnosis and treatment of amenorrhea is a complex process and may include extensive blood testing. Once the cause is determined, the correct amenorrhea treatment can be used to resume menstruation. It may be a process of trial and error since different people respond to different treatments. What is important is that it can be treated.
Resources
MedicineNet.com: Hypothyroidism
 |
