Development of external genitalia during mini-puberty: is it related to somatic growth or reproductive hormones?

Although hypothalamo-pituitary-gonadal axis is active during mini-puberty, its relationship with somatic growth and the role on the development of external genitalia has not been fully elucidated. We aimed to evaluate the effects of somatic growth and reproductive hormones on the development of external genitalia during mini-puberty. Anthropometric data, pubertal assesment, serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), dehydroepiandrosterone sulfate (DHEAS), androstenedione (A4), sex-hormone binding globulin (SHBG), estradiol (E2) and inhibin-B, testosterone (T), and anti-Mullerian Hormone (AMH) of healthy infants aged 1-4 months were evaluated. Free sex hormone index was calculated as T/SHBG for boys and E2/SHBG for girls. The mean age of 148 (74 female) infants included in the study was 2.31 ± 0.76 months. Tanner stage 2-3 sex steroid and gonadotropin levels were observed. A statistically significant difference was found between the weight, height, BMI, weight gain and serum FSH, LH, and A4 measurements of girls and boys (p < 0.05). Penile length was associated with weight (r = 0.24, p = 0.03), height (r = 0.25, p = 0.02), and AMH (r = 0.3, p = 0.01), but not with testosterone (p = 0.56 respectively). A negative correlation was found between weight and serum LH (r = - 0.26, p = 0.2) and T/SHBG levels in males (r = - 0.38, p = 0.015 respectively). Weight-SDS was negatively correlated with testosterone in males (r = - 0.25, p = 0.02). Testicular size and breast stage did not correlate with any of the hormonal and anthropometric parameters.  Conclusions: External genitalia in males during mini-puberty is related more to somatic growth rather than reproductive hormones. Similar to pubertal developmental stages, both total and free testosterone are negatively associated with higher weight during mini-puberty. What is Known: • Mini-puberty allows early assessment of HPG axis function in infancy. • There is an inverse relationship between the amount of adipose tissue and circulating testosterone levels in males during puberty and adulthood. • The potential effect of somatic growth and reproductive hormones on external genital development during mini-puberty remains unclear. What is New: • During mini-puberty, males' external genitalia is more related to somatic growth than to reproductive hormones, but this relationship is not observed in girls. • Both total and free testosterone are negatively associated with higher weight during mini-puberty, similar to the pubertal developmental stages.

Deciphering the Roles & Regulation of Estradiol Signaling during Female Mini-Puberty: Insights from Mouse Models.

Mini-puberty of infancy is a short developmental phase occurring in humans and other mammals after birth. In females, it corresponds to transient and robust activation of the hypothalamo-pituitary-ovarian (HPO) axis revealed by high levels of gonadotropin hormones, follicular growth, and increased estradiol production by the ovary. The roles of estradiol signaling during this intriguing developmental phase are not yet well known, but accumulating data support the idea that it aids in the implementation of reproductive function. This review aims to provide in-depth information on HPO activity during this particular developmental phase in several mammal species, including humans, and to propose emerging hypotheses on the putative effect of estradiol signaling on the development and function of organs involved in female reproduction.

From mini-puberty to pre-puberty: early impairment of the hypothalamus-pituitary-gonadal axis with normal testicular function in children with non-mosaic Klinefelter syndrome.

PURPOSE: Klinefelter syndrome (KS) is a genetic disorder caused by the presence of an extra X chromosome in males. The aim of this study was to evaluate the hypothalamic-pituitary-gonadal (HPG) axis and the clinical profile of KS boys from mini-puberty to early childhood. PATIENTS AND METHODS: In this retrospective, cross-sectional, population study, 145 KS boys and 97 controls aged 0-11.9 years were recruited. Serum FSH, LH, testosterone (T), Inhibin B (INHB), sex hormone binding globulin (SHBG) and anti-Müllerian hormone (AMH) were determined. Auxological parameters were assessed. To better represent the hormonal and clinical changes that appear in childhood, the entire population was divided into 3 groups: ≤ 6 months (group 1; mini-puberty); > 6 months and ≤ 8 years (group 2; early childhood); > 8 and ≤ 12 years (group 3; mid childhood). RESULTS: During mini-puberty (group 1), FSH and LH were significantly higher in KS infants than controls (p < 0.05), as were INHB and T (respectively p < 0.0001 and p < 0.005). INHB was also significantly higher in KS than controls in group 2 (p < 0.05). AMH appeared higher in KS than in controls in all groups, but the difference was only statistically significant in group 2 (p < 0.05). No significant differences were found in height, weight, testicular volume, and penile length. CONCLUSIONS: No hormonal signs of tubular or interstitial damage were found in KS infants. The presence of higher levels of gonadotropins, INHB and testosterone during mini-puberty and pre-puberty may be interpreted as an alteration of the HPG axis in KS infants.

Prenatal exposure to perfluorodecanoic acid is associated with lower circulating concentration of adrenal steroid metabolites during mini puberty in human female infants. The Odense Child Cohort.

BACKGROUND: Fetal programming of the endocrine system may be affected by exposure to perfluoroalkyl substances (PFAAs), as they easily cross the placental barrier. In vitro studies suggest that PFAAs may disrupt steroidogenesis. "Mini puberty" refers to a transient surge in circulating androgens, androgen precursors, and gonadotropins in infant girls and boys within the first postnatal months. We hypothesize that prenatal PFAA exposure may decrease the concentrations of androgens in mini puberty. OBJECTIVES: To investigate associations between maternal serum PFAA concentrations in early pregnancy and serum concentrations of androgens, their precursors, and gonadotropins during mini puberty in infancy. METHODS: In the prospective Odense Child Cohort, maternal pregnancy serum concentrations of five PFAAs: Perfluorohexane sulfonic acid (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) were measured at median gestational week 12 (IQR: 10, 15) in 1628 women. Among these, offspring serum concentrations of dehydroepiandrosterone (DHEA), dehydroepiandrosterone-sulfate (DHEAS), androstenedione, 17-hydroxyprogesterone (17-OHP), testosterone, luteinizing (LH) and follicle stimulating hormones (FSH) were measured in 373 children (44% girls; 56% boys) at a mean age of 3.9 (±0.9 SD) months. Multivariate linear regression models were performed to estimate associations. RESULTS: A two-fold increase in maternal PFDA concentration was associated with a reduction in DHEA concentration by -19.6% (95% CI: -32.9%, -3.8%) in girls. In girls, also, the androstenedione and DHEAS concentrations were decreased, albeit non-significantly (p < 0.11), with a two-fold increase in maternal PFDA concentration. In boys, no significant association was found between PFAAs and concentrations of androgens, their precursors, and gonadotropins during mini puberty. CONCLUSION: Prenatal PFDA exposure was associated with significantly lower serum DHEA concentrations and possibly also with lower androstenedione and DHEAS concentrations in female infants at mini puberty. The clinical significance of these findings remains to be elucidated.

Evaluation of vitamin D status and its correlation with gonadal function in children at mini-puberty.

CONTEXT: The effects of Vitamin D on reproductive function in adults have gained interest. Studies have demonstrated some associations. Hypothalamic-pituitary-gonadal axis is activated during the first 6 months of life, called as mini-puberty. This HPG activation is important for future gonadal function. There are no data regarding the association of gonadal hormones and 25(OH)D levels at mini-puberty. Demonstration of any association would form the basis for studies that will search for the effects of 25(OH)D on gonadal hormones at mini-puberty. OBJECTIVE: To characterize the associations between 25(OH)D levels and gonadal hormones at mini-puberty. DESIGN: Cross-sectional cohort analysis. PATIENT(S) OR OTHER PARTICIPANT(S): A total of 180 (94 boys and 86 girls) healthy appropriate-for-gestational-age neonates were included. MAIN OUTCOME MEASURE(S): 25(OH)D, LH, FSH, total testosterone, oestradiol, AMH and inhibin B levels were measured at postnatal 30-45 days. All infants were divided into three groups including vitamin D deficiency (<10 ng/mL), vitamin D insufficiency (10-20 ng/mL) and vitamin D sufficiency (>20 ng/mL). Correlations between vitamin D status and reproductive hormones were analysed. RESULT(S): Total testosterone level was higher (mean: 0.52 ± 0.32 vs 0.26 ± 0.2 ng/mL; P: 0.008) and inhibin B was lower in 25(OH)D deficient than sufficient girls (mean: 21.2 ± 15.71 vs 53.25 ± 47.25 pg/mL; P: 0.021). CONCLUSION(S): A modest effect of 25(OH)D was identified on total testosterone and inhibin B in girls at mini-puberty. The 25(OH)D may have an effect on gonadal function during early life. Randomized controlled trials could clarify the importance of vitamin D on gonadal hormones at mini-puberty.

Genes Involved in Long-Term Memory Are Expressed in Testis of Cryptorchid Boys and Respond to GnRHa Treatment.

It has been known for many years that boys with unilateral or bilateral undescended testis (cryptorchidism) tend to have a low IQ, and those who belong to the high infertility risk (HIR) group perform less well at school than low infertility risk (LIR) patients. However, the molecular biological processes underlying this phenomenon are not understood. In this study, we report the outcome of testicular RNA profiling for genes involved in long-term memory formation. We analyzed the histology and the transcriptome of testicular biopsies from bilateral HIR cryptorchid boys, comparing those who received GnRHa treatment for 6 months after the first surgery with those who did not receive GnRHa before the second surgery. We found that GnRHa treatment alters the testicular mRNA levels of neuronal genes that are involved in long-term memory and testosterone synthesis. These data highlight a possible molecular link between cryptorchidism, impaired mini-puberty, and diminished cognitive functions. Our results are consistent with the hypothesis that hypogonadotropic hypogonadism in cryptorchid boys with altered mini-puberty may affect neuronal genes important for memory and learning, which could help explaining the negative correlation between cryptorchidism and intellectual abilities.

Menstrual Bleeding as a Manifestation of Mini-Puberty of Infancy in Severe Prematurity.

We report 2 infants with severe prematurity who presented with uterine bleeding at age 6 months (approximately 2.5 months corrected for gestational age). Mini-puberty of infancy should be considered in the differential diagnosis of girls who present with uterine bleeding during the first 6 months of life.

Postnatal penile growth concurrent with mini-puberty predicts later sex-typed play behavior: Evidence for neurobehavioral effects of the postnatal androgen surge in typically developing boys.

The masculinizing effects of prenatal androgens on human neurobehavioral development are well established. Also, the early postnatal surge of androgens in male infants, or mini-puberty, has been well documented and is known to influence physiological development, including penile growth. However, neurobehavioral effects of androgen exposure during mini-puberty are largely unknown. The main aim of the current study was to evaluate possible neurobehavioral consequences of mini-puberty by relating penile growth in the early postnatal period to subsequent behavior. Using multiple linear regression, we demonstrated that penile growth between birth and three months postnatal, concurrent with mini-puberty, significantly predicted increased masculine/decreased feminine behavior assessed using the Pre-school Activities Inventory (PSAI) in 81 healthy boys at 3 to 4years of age. When we controlled for other potential influences on masculine/feminine behavior and/or penile growth, including variance in androgen exposure prenatally and body growth postnally, the predictive value of penile growth in the early postnatal period persisted. More specifically, prenatal androgen exposure, reflected in the measurement of anogenital distance (AGD), and early postnatal androgen exposure, reflected in penile growth from birth to 3months, were significant predictors of increased masculine/decreased feminine behavior, with each accounting for unique variance. Our findings suggest that independent associations of PSAI with AGD at birth and with penile growth during mini-puberty reflect prenatal and early postnatal androgen exposures respectively. Thus, we provide a novel and readily available approach for assessing effects of early androgen exposures, as well as novel evidence that early postnatal aes human neurobehavioral development.

Mini-Puberty, Physiological and Disordered: Consequences, and Potential for Therapeutic Replacement.

There are 3 physiological waves of central hypothalamic-pituitary-gonadal (HPG) axis activity over the lifetime. The first occurs during fetal life, the second-termed "mini-puberty"-in the first months after birth, and the third at puberty. After adolescence, the axis remains active all through adulthood. Congenital hypogonadotropic hypogonadism (CHH) is a rare genetic disorder characterized by a deficiency in hypothalamic gonadotropin-releasing hormone (GnRH) secretion or action. In cases of severe CHH, all 3 waves of GnRH pulsatility are absent. The absence of fetal HPG axis activation manifests in around 50% of male newborns with micropenis and/or undescended testes (cryptorchidism). In these boys, the lack of the mini-puberty phase accentuates testicular immaturity. This is characterized by a low number of Sertoli cells, which are important for future reproductive capacity. Thus, absent mini-puberty will have detrimental effects on later fertility in these males. The diagnosis of CHH is often missed in infants, and even if recognized, there is no consensus on optimal therapeutic management. Here we review physiological mini-puberty and consequences of central HPG axis disorders; provide a diagnostic approach to allow for early identification of these conditions; and review current treatment options for replacement of mini-puberty in male infants with CHH. There is evidence from small case series that replacement with gonadotropins to mimic "mini-puberty" in males could have beneficial outcomes not only regarding testis descent, but also normalization of testis and penile sizes. Moreover, such therapeutic replacement regimens in disordered mini-puberty could address both reproductive and nonreproductive implications.

Combined gonadotropin therapy to replace mini-puberty in male infants with congenital hypogonadotropic hypogonadism.

Infants born with severe central disorders of the hypothalamic-pituitary-gonadal axis leading to gonadotropin deficiency not only lack pubertal development in adolescence, but also lack infantile mini-puberty. This period of mini-puberty, where infants have gonadotropin and sex steroid concentrations up into the adult range, is vital for future reproductive capacity, particularly in boys. At present, there is no consensus on the diagnosis or management of infants with gonadotropin deficiency due to congenital hypogonadotropic hypogonadism or multiple pituitary hormone deficiency. Case series suggest that gonadotropin treatment in male infants with absent mini-puberty is effective in promoting both testicular descent in those with undescended testes and also facilitating increased penile size. Moreover, replacement with follicle-stimulating hormone increases the testicular Sertoli cell population, measurable as an increase in testicular volume and inhibin B, thus hypothetically increasing the capacity for spermatogenesis in adult life for these patients. However, long-term follow-up data is limited for both outcomes pertaining to fertility and nonreproductive sequelae, including neurodevelopment and psychological well-being. The use of international registries for patients with gonadotropin deficiency is a key element in the collection of high-quality, geographically widespread data to inform best-practice management from birth to adulthood.

Gonadotropin administration to mimic mini-puberty in hypogonadotropic males: pump or injections?

Objective: Newborns with congenital hypogonadotropic hypogonadism (CHH) have an impaired postnatal activation of the gonadotropic axis. Substitutive therapy with recombinant gonadotropins can be proposed to mimic physiological male mini-puberty during the first months of life. The aim of this study was to compare the clinical and biological efficacy of two treatment modalities of gonadotropins administration during mini-puberty in CHH neonates. Design: Multicenter retrospective analytical epidemiological study comparing two treatments, pump vs injection, between 2004 and 2019. Methods: Clinical (penile size, testis size, testicular descent) and biological parameters (serum concentrations of testosterone, anti-Müllerian hormone (AMH) and Inhibin B) were compared between the two groups by multivariate analyses. Results: Thirty-five patients were included. A significantly higher increase in penile length and testosterone level was observed in the injection group compared to the pump group (+0.16 ± 0.02 mm vs +0.10 ± 0.02 mm per day, P = 0.002; and +0.04 ± 0.007 ng/mL vs +0.01 ± 0.008 ng/mL per day, P = 0.001). In both groups, significant increases in penile length and width, testosterone, AMH, and Inhibin B levels were observed, as well as improved testicular descent (odds ratio of not being in a scrotal position at the end of treatment = 0.97 (0.96; 0.99)). Conclusions: Early postnatal administration of recombinant gonadotropins in CHH boys is effective in stimulating penile growth, Sertoli cell proliferation, and testicular descent, with both treatment modalities.

Androgen receptor signaling regulates follicular growth and steroidogenesis in interaction with gonadotropins in the ovary during mini-puberty in mice.

In females, androgens contribute to ovarian diseases such as polycystic ovarian syndrome (PCOS), but their action is also crucial for ovarian physiology, i.e., follicular growth and estradiol (E2) synthesis during reproductive life, in interaction with the gonadotropins LH and FSH. However, it is unclear whether androgens already play a role in the ovary at mini-puberty, a phase of postnatal development with active follicular growth and high E2 levels. Therefore, we analyzed the potential actions of androgens on the ovary and their possible interaction with gonadotropins during this period in mice. We used molecular-based studies and pharmacological approaches in vivo and on cultured ovaries. We found that mini-pubertal ovaries produce significant amounts of testosterone and display androgen receptor (AR) expression in growing follicles, both under the control of LH. By blocking AR signaling either in vivo or in ovarian cultures, we found that this pathway may participate in the regulation of prepubertal E2 synthesis and follicular growth, possibly by regulating the expression of a number of key intra-ovarian regulators, including FSH receptor (Fshr), the aromatase enzyme converting androgens into estrogens (Cyp19a1) and the cell cycle inhibitor p27KIP1 (Cdkn1b). We further showed that AR may stimulate FSH-mediated regulation of Cyp19a1 through its action on Fshr mRNA abundance. Overall, this work supports the idea that AR signaling is already activated in mini-pubertal ovaries to regulate E2 synthesis and follicular growth, at the interplay with LH and FSH signaling. Its early action may, thus, contribute to the implementation of early ovarian function with possible impacts on reproductive function.

Mini-puberty testosterone and infant autistic traits.

Background: Levels of steroid hormones in the first three months of life, a period referred to as 'mini-puberty', are one of the earliest physiological differences between typical males and females postnatally. Autistic traits also show consistent typical sex differences in later infancy, after the 18th month of life. Previous studies have shown prenatal testosterone is associated with later levels of autistic traits. Studies testing if postnatal testosterone levels are associated with autistic traits have reported null results. No studies to date have investigated mini-puberty longitudinally or tested for interactions with baseline sex differences or familial likelihood of autism. Methods: The 'Cambridge Human Imaging and Longitudinal Development Study' (CHILD) is a prospective enriched cohort study in Cambridge, UK. It includes physiological measurements in early infancy, as well as neurodevelopmental follow-ups over the first two years of life. A subset of the cohort also includes children with a family history of autism (a diagnosed parent or sibling). Salivary testosterone levels were assessed at two time-points, just after the 2nd and 6th month of life. Autistic traits were measured using the Quantitative Checklist of Autism in Toddlers (Q-CHAT) when the children were 18 months of age. Results: Salivary testosterone levels were significantly higher during 'mini-puberty' in the 2nd and 3rd month of life, compared to after the 6th month of life, in both males and females. There was no significant sex difference at either time-point. Log-transformed testosterone levels were not associated with autistic traits (Q-CHAT). There was no interaction effect with infant sex, autism family history or baseline testosterone levels after mini-puberty (at >6 months of age). Conclusion: Both male and female infants have elevated levels of salivary testosterone during mini-puberty but in this relatively small sample this was not associated with their later autistic traits at 18 months or their family history of autism. This suggests that prenatal rather than postnatal testosterone levels are more relevant for understanding the causes of autism. Future studies should test these relationships in larger samples.

Exaggerated mini-puberty in a preterm girl: a case report and review of literature.

OBJECTIVES: Mini-puberty is the physiological and transient activation of the hypothalamic-pituitary-gonadal axis occurring during the first months after birth. In preterm infants, the hormonal surge is more pronounced and longer-lasting than in at-term-peers. To date, only few cases of vaginal bleeding in the setting of an exaggerated mini-puberty have been reported. CASE PRESENTATION: At the corrected age of 3 months, an ex-very-preterm girl presented with breast enlargement and recurrent vaginal bleeding. A remarkable increase in gonadotropins and estradiol levels was detected, while pelvic ultrasound highlighted a large right ovarian cyst. As brain and pituitary MRI showed negative findings, an exaggerated mini-puberty was suspected and no additional investigations were undertaken. The subsequent progressive regression of clinical, biochemical and sonographic findings confirmed the diagnosis. CONCLUSIONS: Although exaggerated mini-puberty of infancy in ex-preterm girls is a rare event, it is important to raise knowledge of this para-physiological condition in order to avoid unnecessary investigations and treatment.

Longitudinal Sex Steroid Data in Relation to Birth Weight in Preterm Boys.

CONTEXT: There is a lack of knowledge on longitudinal sex steroid patterns during infancy, especially for boys born preterm or with low birth weight (LBW). OBJECTIVE: To find out whether LBW boys have a disturbed sex steroid profile during infancy. DESIGN AND SETTING: Population-based longitudinal study performed at Sahlgrenska University Hospital, Gothenburg, Sweden. PARTICIPANTS: Ninety-eight singleton boys (47 LBW) born at gestational age 32.0 to 36.9 weeks were included. Because of dropout, 83 of the boys were still in the study at 10 months' corrected age. MAIN OUTCOME MEASURES: Serum androgen and estrogen concentrations were analyzed by gas chromatography-tandem mass spectrometry and IGF-I was determined with radioimmunoassay in umbilical cord and at 0, 2, 5, and 10 months' corrected age. RESULTS: Serum levels of androstenedione, estrone, and estradiol declined gradually from birth to 10 months corrected age. In both LBW boys and their counterparts, a surge was seen at 2 months' corrected age (3 months' chronological age) for testosterone, median (range) 6.5 (2.0-18.9) nmol/L, and in dihydrotestosterone 1.2 (0.4-4.3) nmol/L. At birth, LBW boys had higher median testosterone (0.7 vs 0.4 nmol/L, P = 0.019), and at 0 months' corrected age, both had higher testosterone (5.7 vs 3.5 nmol/L, P = 0.003) and dihydrotestosterone (1.2 vs 0.9 nmol/L, P = 0.006) than their counterparts. At 10 months' corrected age, catch-up in weight SD score from birth correlated with testosterone (rho = 0.27, P = 0.044) and androstenedione (rho = 0.29, P = 0.027). CONCLUSIONS: Moderately to late preterm LBW boys showed a disturbed sex hormone profile, with elevated concentrations of androgens in early infancy.

Functional Importance of Mini-Puberty in Spermatogenic Stem Cell Formation.

Primordial germ cells nesting in the fetal testis give rise to gonocytes. The gonocytes then transform into spermatogenic stem cells (SSCs) during the neonatal period and thereafter serve as a lifetime source of spermatogenesis. Therefore, gonocyte to SSC transformation is quite an important process that supports fertility in males. During the gonocyte to SSC transformation, morphological and transcriptomic changes sequentially occur and gonocytes migrate from the center to the peripheral region of the seminiferous tubules. However, extrinsic signals which trigger the transcriptomic changes as well as the migration are not yet fully clarified. Recent studies have drawn attention to the temporal activation of the hypothalamic-pituitary-gonadal axis during the neonatal stage which occurs concurrently with SSC formation. This phenomenon is called mini-puberty, and recent studies on human cryptorchid patients as well as animal models partially support the hypothesis that mini-puberty plays pivotal roles in gonocyte-to-SSC transformation. Focusing on this point, here, we aimed to discuss the latest knowledge on the importance of mini-puberty in spermatogenesis in this review.

Exaggerated Mini Puberty during Early Infancy of a Preterm Girl: A Case Report and Review of Literature.

Mini puberty is the important period of infancy life that can have a serious impact on sexual development in both sexes. In the infants born very preterm and with extremely low birth weight, mini puberty changes including changes in clinical, hormonal, and imaging data are severe and long lasting, especially in girls. It can be called "exaggerated mini puberty". In this study, a 6-month preterm infant with bronchopulmonary dysplasia presented with periodic vaginal bleeding, Tanner stage 3 breast development, and Tanner stage 2 pubic hair. We did follow up clinical and para-clinical evaluations for the infant during one year and compared the obtained data with those of similar published articles. During one year of monitoring, the case gradually grew to the normal pre-pubertal state, without any hormonal suppressive treatment. Exaggerated mini puberty is a temporary physiologic state in very low birth weight (VLBW) preterm infants that does not require any extra hormonal and surgical interventions.

The role of scrotal ultrasonography from infancy to puberty.

BACKGROUND: Scrotal ultrasonography is an essential diagnostic tool in daily clinical practice. The availability of new-generation ultrasound machines characterized by clearly improved image quality, low health cost, and higher patient safety, represents only some characteristics of ultrasound investigation. The usefulness of scrotal ultrasonography is particularly evident in the period of life from infancy to puberty, during which males undergo important morphofunctional changes, and several pathological conditions may occur. OBJECTIVES: This pictorial review primarily aimed to investigate the aspects of ultrasonography related to the normal physiological development of the gonads from mini-puberty to pubertal onset. This study also aimed to provide an update on the use of ultrasonography in main andrological pathologies that may occur during this period. The conditions that are discussed in depth are: cryptorchidism, inguinoscrotal hernias, and hydrocele in the neonatal phase; acute scrotum, epididymo-orchitis, and testicular cancers in childhood; and hypogonadism, varicoceles, testicular microlithiasis, and oncohematological pathology in puberty. DISCUSSION: We provided an ultrasound slant for all the above-mentioned pathologies while purposely avoiding excessive deepening of the pathogenetic, clinical, and therapeutic aspects. Studying the ultrasound aspects of the gonads also facilitates differential diagnosis between various conditions and represents a good aid in evaluating therapeutic success (e.g., in hypogonadism or postsurgical evaluation of varicoceles and cryptorchidism). CONCLUSION: Scrotal ultrasonography is now globally recognized as the necessary completion of clinical-laboratory overview in gonads evaluation. This diagnostic procedure is even more indispensable in the infancy-childhood-puberty period for the evaluation of normal gonadal development as well as diagnosis of other possible diseases.