Sanfilippo's Textbook of Pediatric and Adolescent Gynecology

Joseph S. Sanfilippo, Eduardo Lara-Torre, Veronica Gomez-Lobo, Joseph S. Sanfilippo, Eduardo Lara-Torre, Veronica Gomez-Lobo

• Publisher: CRC Press
• Year: 2019
• eBook ISBN: 9781351375849
• Topic: Medizin
• Subtopic: Familien- & Hausarztpraxis

This textbook provides a comprehensive review of all the common and less often encountered pediatric and adolescent gynecology problems in daily practice, both in the ambulatory as well as in the surgical setting. This new edition has been updated to keep it closely aligned to what general gynecologists or family physicians will want to know when dealing with a paediatric or adolescent patient, with accompanying videos.

1

Normal pubertal development and the menstrual cycle as a vital sign*

Meredith Loveless

Puberty consists of a complex interplay of hormonal and physiologic changes that result in sexual maturation and capability for reproduction.1 This transition is an important phase of development accompanied by physical, social, and behavioral changes. Health-care providers play an important role during this time in monitoring that the process is occurring within normal parameters and providing evaluation if concerns in development arise. In most cases, the process of puberty occurs normally, although there is a broad variation of “normal” that may lead to anxiety in some patients and families. When the pubertal process does not occur within standards of normal, it may represent underlying health concerns and alert the health-care provider of the need for further evaluation and possible interventions. This chapter reviews the stages of normal puberty in females and provides guidance on abnormalities that may require investigation.

Timing of puberty

Girls normally begin puberty between 8 and 13 years of age.2 Thelarche is usually the first sign of puberty followed by pubarche; although 15% of girls will experience pubarche first.3 Vaginal bleeding before thelarche does not typically represent menarche and should be evaluated. The physiologic mechanism for timing of puberty is not known. There are multiple factors that influence pubertal timing, including genetic, environmental, neuropeptides, energy balance, intrinsic factors, stress, and sleep; however, the key regulatory step for activation of puberty is unknown.1 Sexual maturation declined rapidly during the first half of the twentieth century attributed to better nutrition as the Western world developed but has remained steady the latter part of the twentieth century. Age of menarche has declined minimally; however, age of thelarche appears to continue to decline.4 There appears to be a trend toward earlier age to reach Sexual Maturation Rating (SMR) 2 but the age for SMR 3 and age of menarche remains steady.5 Delayed puberty is defined as lack of pubertal development by an age that is 2–2.5 standard deviations beyond the population mean.6 In the United States, lack of breast development (SMR 2) by age 13 and menses that has not started within 3 years of thelarche or by age 15 warrant evaluation.6,7 Precocious puberty is defined as pubertal changes occurring prior to the age of 8 years, although the earlier onset of thelarche makes this age cutoff more controversial. Further discussion on the anomalies of puberty is included in Chapter 5.

It is plausible that the earlier onset of breast development is related to environmental factors. These factors are called endocrine disruptors and are environmental chemicals, dietary supplements, and/or medications that interfere with the endocrine system.8 There is evidence from animal studies that endocrine disruptors affect pubertal timing, but studies in humans have been more difficult and are not currently well understood.5 More research is needed to understand how medications, environmental agents, and nutritional deficiencies, as well as supplements, can impact pubertal timing. One environmental agent that was found to disrupt puberty in animals and is found in higher levels in children with higher adiposity is biphenol A (BPA). Found in plastic bottles and toys, it has been linked to having an estrogenic effect at low levels and to competing with endogenous estrogen for binding and antiandrogenic properties at higher levels.9 Chemicals, pesticides, dioxins, polychlorinated biphenyls (PCBs), and flame retardants are present across the ecosystem and have been detected in humans.9 Exposure to a broad mixture of environmental contaminants makes it challenging to determine if these substances are playing a role in pubertal timing and what that role is; however, growing evidence suggests there is environmental impact on pubertal timing.

Another important factor that may influence pubertal timing is obesity. Multiple studies show a correlation between increased body mass index (BMI) and early puberty.5 The National Health and Nutrition Examination Survey III (NHANES III) collected pubertal data from 2300 U.S. children ages 8 years and up from 1988 to 1994. This data showed children with a BMI greater than the 85th percentile were strongly associated with earlier age of breast development and menarche, with menarche occurring at a mean age of 12.06 in obese girls compared to 12.57 in nonobese girls.10 Additional studies suggest that rapid weight gain and early puberty followed by development of obesity, and metabolic syndrome lead to an overall increase in mortality that persists into adulthood.5 Data have not shown obesity alone as the primary cause of earlier pubertal timing. Some studies suggest leptin, which is related to growth and pubertal development and affects appetite, adiposity, and energy regulation, may be a link associated with this finding.4 It is also postulated that endocrine disruptors may act on adipocytes, thereby linking early puberty and obesity.4

Early puberty has also been associated with higher rates of depression, anxiety, smoking, delinquent behavior, and early sexual experiences.5 Chronic stress including a lower socioeconomic status has also been associated with early puberty.5,10 It is difficult to determine if the consequences of obesity, such as bullying, stress from difficult social situations, or early puberty itself, are related to the link with mood and behavior changes.

Hormonal changes

Puberty is initiated and controlled by a complex relationship of multiple hormones. The regulatory steps to initiation of puberty are still unknown. The hypothalamus secretes gonadotropin-releasing hormone (GnRH), which signals the gonadotrophs in the pituitary to release gonadotrophins: luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Luteinizing hormone acts on the theca cells in the ovary to produce androgens, and FSH acts on ovarian follicles to produce estradiol, inhibin, and gametes. The interplay is called the hypothalamic-pituitary-gonadal (HPG) axis (Figure 1.1).3 During the first 3 months of life, under the influence of maternal estrogen exposure in utero, LH and FSH levels are high. By age 6 months, LH levels are almost undetectable. While FSH levels decrease after the first 6 months, they can remain elevated until age 3–4 years.3 At this point, the HPG axis remains quiescent until activation initiates puberty. The LH level is generally the most useful marker for assessing onset of puberty with elevated levels in childhood indicating central nervous system activity related to onset of ...

Table of contents

• Cover
• Title Page
• Copyright Page
• Contents
• Preface: We need the tools to get the job done
• Contributors
• 1. Normal pubertal development and the menstrual cycle as a vital sign
• 2. Communication strategies with the adolescent patient
• 3. The physical exam in the pediatric and adolescent patient
• 4. Adolescent sexual development and sexuality education
• 5. Pubertal abnormalities: Precocious and delayed
• 6. Congenital anomalies of the reproductive tract
• 7. Variation of sex differentiation
• 8. Common vulvar and vaginal complaints
• 9. Genital injuries in children and adolescents
• 10. Basic dermatology in children and adolescents
• 11. Pediatric urology
• 12. Adnexal masses in the neonate, child, and adolescent
• 13. Breast disorders in children and adolescents
• 14. Menstrual disorders and blood dyscrasias in adolescents
• 15. Polycystic ovary syndrome and hyperandrogenism in adolescents
• 16. Adolescent contraception
• 17. Sexually transmitted infections in adolescents
• 18. Chronic pelvic pain and endometriosis
• 19. Perioperative care of the pediatric and adolescent gynecology patient
• 20. Adolescent pregnancy
• 21. Nutrition and eating disorders
• 22. Reproductive effects of obesity in adolescents
• 23. Transgender care in adolescents
• 24. Reproductive health care for adolescents with developmental delay
• 25. Sexual abuse
• 26. Fertility preservation in pediatric and adolescent girls
• 27. Confidential care issues
• 28. Family and cultural factors in pediatric gynecology
• 29. Health-care transition
• 30. Legal considerations in pediatric and adolescent obstetrics and gynecology
• Appendix 1: Additional video resources
• Appendix 2: Establishing a pediatric and adolescent gynecology clinical and educational program
• Index