MENSTRUAL DISORDERS IN ADOLESCENTS

Journal of Nepal Medical Association 2004; 43: 152-163 REVIEW ARTICLE MENSTRUAL DISORDERS IN ADOLESCENTS Dangal G ABSTRACT The health problems of adolescents are very special. Menstrual disorders such as amenorrhea, abnormal/ excessive uterine bleeding, dysmenorrhea, and premenstrual syndrome are particularly common in adolescent girls. Although menstrual irregularities may be normal during the early postmenarchal years, pathological conditions require proper and prompt management. This article reviews the topic: menstrual disorders and discusses their etiologies, diagnosis and treatment modalities. It also reviews the normal and abnormal menstrual cycles. The knowledge of the normal menstrual cycle is very important in managing these disorders properly. Key Words: Adolescent, amenorrhea, dysfunctional uterine bleeding, dysmenorrhea, menstrual disorder, premenstrual syndrome. INTRODUCTION Menstrual disorders are a common problem in adolescents. These disorders are often the source of anxiety for the patients and the families. The common menstrual disorders in adolescents are amenorrhea, abnormal/excessive uterine bleeding, dysmenorrhea, and premenstrual syndrome.1 The median age of menarche is 12.9 years.2 The length of the normal menstrual cycle is highly variable. Normal menstrual cycles are characterized by a cycle length of 28 days (+ 7 days), a duration of flow of 4 days (+ 2 days), and a blood loss of 40 mL (+ 20 mL).3 The mean volume of menstrual blood loss is 43 mL, with a normal range of 20-80 mL. 4 Cycles are abnormal if they are longer than 8 to 10 days in duration or if more than 80 mL of blood loss occurs, particularly after the first 2 years from the onset of menarche. It is very difficult to quantify the blood loss however; soaking more than 25 pads or 30 tampons during a menstrual period is usually Address for correspondence : abnormal. Abnormal/irregular menstrual patterns are common during the first 2 years after menarche and the variability in cycle length is greater during adolescence than adulthood; thus greater irregularity is acceptable if significant anemia or hemorrhage is not present.5 The normal menstrual cycle Menstruation is the monthly physiologic shedding of the endometrium. The menstrual cycle is regulated by a combination of the hypothalamus, hypophysis, ovaries, and uterus.The hypothalamus and the pituitary gland regulate the reproductive hormones. 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. The hypothalamus first releases gonadotropin-releasing hormone (GnRH). GnRH, in turn, stimulates the pituitary gland to produce follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The ovaries at the command of FSH and LH secrete estrogen and progesterone. Dr. Ganesh Dangal Binayak Maternity Hospital, Gausala, Kathmandu, Nepal Email: JNMA, May - June, 2004, 43 153 Dangal . Menstrual Disorders in Adolescents Normal menstruation results from progesterone withdrawal from estrogen-primed endometrium. Menstrual cycle is the result of a complex interaction between the various organs as shown in Fig.1. Dysfunction at any level can interfere with ovulation and the menstruation. is formed and no progesterone is secreted. The endometrium continues its proliferative phase excessively. When the follicle involutes, estrogen levels drop and its withdrawal bleeding occurs. Most anovulatory cycles are regular with normal bleeding; however, the unstable proliferative endometrium can shed irregularly, resulting in prolonged heavy bleeding. Hypothalamus The adolescents have amenorrhea, dysmenorrhea, premenstrual syndrome and abnormal uterine bleeding as the common types of menstrual disorders which are dealt in detail below. GnRH Anterior Pituitary FSH/LH Amenorrhea Ovaries Estrogen Proliferative (Follicular) Phase Progesterone Secretory (Luteal) Phase Fig.1 : Pathway of action of hormones for normal menstrual function.6 Adolescents frequently experience irregular menstrual bleeding patterns, which can include several consecutive months of amenorrhea. Amenorrhea-except that occurring before puberty, during pregnancy or early lactation, and after menopause-is pathologic. Amenorrhea may be caused by anatomic abnormalities; hypothalamic, pituitary, or other endocrine dysfunction; ovarian failure; or genetic defects (Table I). Hormonal changes in the normal menstrual cycle During the follicular phase, release of GnRH stimulates the pituitary to secrete FSH and LH, which then stimulate ovarian estrogen secretion ultimately inducing endometrial proliferation. With the start of each menstrual cycle, FSH stimulates several follicles to mature over a two-week period. Only one follicle becomes dominant, however, during a cycle. These follicles produce estrogen, which enters the bloodstream and reaches the uterus where it stimulates the endometrial cells to reproduce, therefore thickening the walls. Estrogen levels reach their peak around the 14th day of the cycle. As estrogen levels peak, the pituitary gland releases increased amounts of LH. Ovulation occurs about 12 hours after the midcycle surge in LH. The luteal phase follows ovulation, and the corpus luteum secretes progesterone and estrogen. Progesterone inhibits endometrial proliferation and induces glandular changes. Without fertilization, the corpus luteum regresses, resulting in a decrease in progesterone and estrogen, and shedding of the endometrium (menses) 14 days after ovulation. Hormonal changes during anovulatory cycles Anovulatory cycles are common in the first 2 years after menarche because of the immaturity of the HPO axis. 5,7 Anovulation also can occur in a variety of pathological conditions. In anovulatory cycles, the follicular growth occurs with the stimulation from FSH; however, due to lack of LH surge, ovulation fails to occur. Consequently, no corpus luteum Amenorrhea may be primary (never menstruated) or secondary (i.e., menarche, but no periods for 3 consecutive months). Primary amenorrhea is defined as the absence of the menses by 16 years of age in the presence of normal secondary sexual characteristics or by 14 years of age when there is no visible secondary sexual characteristics development.9 The American College of Obstetricians and Gynecologists recommends that a young woman consult her physician if she has not started to menstruate by the age of 16, and/or if she has not begun to develop breast buds, pubic hair, or underarm hair by the age of 13 or 14. A woman who has previously menstruated can develop secondary amenorrhea, which can be defined as the absence of menses for consecutive 3 months. Secondary amenorrhea is more common than primary one. The most common etiology is dysfunction of the hypothalamic-pituitary-ovarian (HPO) axis. A careful history, a detailed examination and appropriate investigations (hormonal assay, imaging and others) are neces (...truncated)