A retrospective review of the use of bicalutamide in transfeminine youth; a single center experience.

Background: Androgen blockers are an essential part of gender affirming care in post-pubertal transfeminine patients. Bicalutamide is a highly potent androgen receptor blocker that is used primarily in adults. We aimed to review our experience with the use of bicalutamide in transgender adolescents who were assigned male at birth. Methods: A retrospective review of medical records of transfeminine patients treated with bicalutamide during an 8-year period was conducted. Results: Forty patients, aged 15.5 ± 1.55 years were identified, of whom 21 (53%) were started on bicalutamide alone and 19 were started concurrently on estrogen. In patients on bicalutamide alone, 90.4% reported breast development at their first follow up visit, which occurred at a median of 7.1 months. Patients were treated for 29.4 ± 18.2 months. No episodes of liver toxicity related to bicalutamide were seen. Conclusions: Although these results are preliminary, bicalutamide appears to be a safe option for androgen blockade in transgender girls.

Presentation and Care for Children with Peripheral Precocious Puberty.

Peripheral precocious puberty (PPP) refers to the early onset of sexual maturation that is independent of central nervous system control. The extensive differential diagnosis includes congenital and acquired causes. Presenting features depend on which class of sex steroids is involved, and diagnosis rests on hormonal and, if indicated, imaging and/or genetic studies. Effective treatment exists for nearly all causes of PPP. Ongoing research will advance our therapeutic armamentarium and understanding of the pathophysiologic basis of these conditions.

Hypogonadotropic Hypogonadism.

Delayed puberty is defined as absent testicular enlargement in boys or breast development in girls at an age that is 2 to 2.5 SDS later than the mean age at which these events occur in the population (traditionally, 14 years in boys and 13 years in girls). One cause of delayed/absent puberty is hypogonadotropic hypogonadism (HH), which refers to inadequate hypothalamic/pituitary function leading to deficient production of sex steroids in males and females. Individuals with HH typically have normal gonads, and thus HH differs from hypergonadotropic hypogonadism, which is associated with primary gonadal insufficiency.

History of Puberty: Normal and Precocious.

Spanning from bench to bedside, the history of normal and precocious puberty is characterized by a series of remarkable advances that have illuminated reproductive physiology and profoundly impacted clinical care. Early recognition of the hypothalamic and pituitary control of ovarian and testicular function led to the identification of GnRH as the key driver of pubertal onset. Decades later, discovery of the kisspeptin system further refined our understanding of human reproductive neuroendocrinology. Development of long-acting analogs of GnRH revolutionized the treatment of precocious puberty worldwide and ushered in the current era of an ever-expanding therapeutic armamentarium. Identification of monogenic etiologies of precocious puberty has further illustrated the exquisite complexity that comprises neurosecretory modulation of the hypothalamic GnRH neuron and may well lead to exciting novel targeted therapies.

Current State of Pediatric Reference Intervals and the Importance of Correctly Describing the Biochemistry of Child Development: A Review.

Importance: Appropriately established pediatric reference intervals are critical to the clinical decision-making process and should reflect the physiologic changes that occur during healthy child development. Reference intervals used in pediatric care today remain highly inconsistent across a broad range of common clinical biomarkers. Observations: This narrative review assesses biomarker-specific pediatric reference intervals and their clinical utility with respect to the underlying biological changes occurring during development. Pediatric reference intervals from PubMed-indexed articles published from January 2015 to April 2021, commercial laboratory websites, study cohorts, and pediatric reference interval books were all examined. Although large numbers of pediatric reference intervals are published for some biomarkers, very few are used by clinical and commercial laboratories. The patterns, extent, and timing of biomarker changes are highly variable, particularly during developmental stages with rapid physiologic changes. However, many pediatric reference intervals do not capture these changes and thus do not accurately reflect the underlying biochemistry of development, resulting in significant inconsistencies between reference intervals. Conclusions and Relevance: There is a need to correctly describe the biochemistry of child development as well as to identify strategies to develop accurate and consistent pediatric reference intervals for improved pediatric care.

Cardiovascular Health of Youth During Gender-Affirming Testosterone Treatment: A Review.

PURPOSE: Many birth-assigned female/transgender male and nonbinary people (identified as masculine spectrum here) begin gender-affirming testosterone therapy by the age of 24 years. Few data inform assessment of cardiovascular health of masculine spectrum youth as a specific subgroup of the 1.5 million transgender people in the United States. The purpose of this review is to help youth-serving practitioners consider, understand, and evaluate cardiovascular health in adolescent and young adult masculine spectrum patients receiving gender-affirming testosterone treatment. METHODS: This is a narrative review intended to synthesize a broad body of clinical and research literature. RESULTS: Common cardiovascular health changes associated with testosterone include increased red blood cell mass and likely insignificant changes in high-density lipoprotein and low-density lipoprotein levels. Changes in heart mass, heart electrophysiology, and endothelial reactivity are likely, based on extrapolation of data from adults. Testosterone may have indirect effects on cardiovascular health through influences on depression, anxiety, stress, and anorexia nervosa as well as on behaviors such as tobacco use. CONCLUSIONS: Testosterone contributes importantly to the cardiovascular health and well-being of masculine spectrum gender-diverse youth. We need to do a better job of supporting these young people with data on cardiovascular health over the life span.

Central precocious puberty in spina bifida children: Guidelines for the care of people with spina bifida.

Children with spina bifida are at greater risk of developing central precocious puberty (CPP) compared to others. Therefore, early recognition and timely referral for further evaluation by a pediatric endocrinologist allows appropriate management that reduces the impact of CPP. This article discusses the diagnosis and management of CPP in children with spina bifida. This guideline was developed for SB Transition Healthcare Guidelines from the 2018 Spina Bifida Association's Fourth Edition of the Guidelines for the Care of People with Spina Bifida.

Short stature and the effect of human growth hormone: Guidelines for the care of people with spina bifida.

It is estimated that a significant percentage of individuals with spina bifida (SB) are shorter than their age-matched typical peers. Parents of children with spina bifida may ask if human growth hormone is appropriate for their child. This article discusses short stature and the use of human growth hormone among children with SB. This guideline was developed for SB Healthcare Guidelines from the 2018 Spina Bifida Association's Fourth Edition of the Guidelines for the Care of People with Spina Bifida.

Individualized care for patients with intersex (disorders/differences of sex development): part I.

The care of individuals with disorders/differences of sex development aims to enable affected individuals and their families to have the best quality of life, particularly those born with severe genital ambiguity. Two of the biggest concerns for parents and health professionals are: (1) making a gender assignment and (2) the decisions of whether or not surgery is indicated, and if so, when is best for the patient and parents. These decisions, which can be overwhelming to families, are almost always made in the face of uncertainties. Such decisions must involve the parents, include multidisciplinary contributions, have an underlying principle of full disclosure, and respect familial, philosophical, and cultural values. Assignment as male or female is made with the realization that gender identity cannot be predicted with certainty. Because of the variability among those with the same diagnosis and complexity of phenotype-genotype correlation, the use of algorithms is inappropriate. The goal of this article is to emphasize the need for individualized care to make the best possible decisions for each patient's unique situation.

Use of Gonadotropin-Releasing Hormone Analogs in Children: Update by an International Consortium.

This update, written by authors designated by multiple pediatric endocrinology societies (see List of Participating Societies) from around the globe, concisely addresses topics related to changes in GnRHa usage in children and adolescents over the last decade. Topics related to the use of GnRHa in precocious puberty include diagnostic criteria, globally available formulations, considerations of benefit of treatment, monitoring of therapy, adverse events, and long-term outcome data. Additional sections review use in transgender individuals and other pediatric endocrine related conditions. Although there have been many significant changes in GnRHa usage, there is a definite paucity of evidence-based publications to support them. Therefore, this paper is explicitly not intended to evaluate what is recommended in terms of the best use of GnRHa, based on evidence and expert opinion, but rather to describe how these drugs are used, irrespective of any qualitative evaluation. Thus, this paper should be considered a narrative review on GnRHa utilization in precocious puberty and other clinical situations. These changes are reviewed not only to point out deficiencies in the literature but also to stimulate future studies and publications in this area.

Bicalutamide as an Androgen Blocker With Secondary Effect of Promoting Feminization in Male-to-Female Transgender Adolescents.

PURPOSE: The purpose of the study was to describe the novel use of bicalutamide in transgender youth. METHODS: This is a retrospective review of patients with gender dysphoria followed in the pediatric endocrine clinic at Riley Hospital for Children. RESULTS: Of 104 patients with gender dysphoria, 23 male-to-female adolescents received bicalutamide 50 mg daily as a second-line puberty blocker after insurance company denial of a gonadotropin-releasing hormone analog. Six patients received estrogen concurrently. Of 13 patients treated exclusively with bicalutamide seen in follow-up, 84.6% had breast development within 6 months, the majority being ≥ Tanner stage III. CONCLUSIONS: Bicalutamide may be an alternative to gonadotropin-releasing hormone analogs in transgender male-to-female youth who are also ready to undergo physical transition.