Onset Of Puberty In Boys Research Articles

Cryptorchidism and puberty.

Cryptorchidism is the condition in which one or both testes have not descended adequately into the scrotum. The congenital form of cryptorchidism is one of the most prevalent urogenital anomalies in male newborns. In the acquired form of cryptorchidism, the testis that was previously descended normally is no longer located in the scrotum. Cryptorchidism is associated with an increased risk of infertility and testicular germ cell tumors. However, data on pubertal progression are less well-established because of the limited number of studies. Here, we aim to review the currently available data on pubertal development in boys with a history of non-syndromic cryptorchidism-both congenital and acquired cryptorchidism. The review is focused on the timing of puberty, physical changes, testicular growth, and endocrine development during puberty. The available evidence demonstrated that the timing of the onset of puberty in boys with a history of congenital cryptorchidism does not differ from that of non-cryptorchid boys. Hypothalamic-pituitary-gonadal hormone measurements showed an impaired function or fewer Sertoli cells and/or germ cells among boys with a history of cryptorchidism, particularly with a history of bilateral cryptorchidism treated with orchiopexy. Leydig cell function is generally not affected in boys with a history of cryptorchidism. Data on pubertal development among boys with acquired cryptorchidism are lacking; therefore, more research is needed to investigate pubertal progression among such boys.

Tanner stages and Prader orchidometry in male adolescents. A descriptive, cross-sectional study.

Introduction. The Tanner scale and the Prader orchidometer are the instruments most commonly used to assess pubertal development in children. The assessment of puberty in the clinic is only useful if recent and reliable references in the same population are available for comparison. Objective: to assess the correlation between Tanner stages and testicular volume (TV) in Argentine adolescents. Population and methods. Study with a descriptive, cross-sectional design conducted in healthy boys aged 9-20 years. Male children and adolescents with urogenital conditions and disorders affecting testicular growth were excluded. The correlation between Tanner stages and TV was assessed using non-parametric tests. Results. A total of 367 male adolescents with an average age of 13.8 ± 2.5 years were assessed. TV increased in correlation to Tanner stages (Spearman: 0.943, p<0.001)withsignificantlydifferent volumes, except in the early genital 1-2 stages (p 0.343) and pubic hair 1-2 stages (p 0.447). Among peripubertalboys,16%(95%confidenceinterval:9.6-24.4%,n=17/106)werewronglyclassifiedbasedon Tanner stages. Conclusions. During male puberty, TV increased in correlation to Tanner stages, but no significantdifferences were observed between Tanner stages 1 and 2. Using the Prader orchidometer is critical to establish the onset of puberty in boys.

Nutrition and puberty

Nutrition plays an important role in the growth, development and puberty of children. Adequate nutrition is very important for the normal development of the child during the various stages of childhood and into puberty. Unfortunately, we note the spread of fast food and the adoption of wrong methods in feeding the child, such as making them watch TV to motivate them to eat a larger amount of food etc. This has led to the spread of obesity and overweight among children. Overweight or obese children are more likely to enter puberty early. Some evidence suggests that obesity can accelerate the onset of puberty in girls and this is a major reason why girls begin puberty at an earlier age compared to past decades while overweight or obesity may delay the onset of puberty in boys. On the other hand, severe primary or secondary malnutrition also can delay the onset and progression of puberty. The aim of our article is to shed light on the relation between nutrition and puberty and to focus on the importance of adequate nutrition to create a healthy child with a normal development. Key words: Nutrition, children, puberty

Association between a soy-based infant diet and the onset of puberty: A systematic review and meta-analysis.

The objective of this systematic review was to evaluate the association between a soy-based infant diet and the onset of puberty. We included studies in which children were fed a soy-based diet, and we compared them with those who were not. The primary outcomes were the onset of puberty in girls (thelarche, pubarche, and menarche age), boys (pubarche, voice change, testicular and penis enlargement age), and both (risk of delayed and precocious puberty [PP]). Search strategies were performed in PubMed, Embase, LILACS, and CENTRAL databases. Two reviewers selected eligible studies, assessed the risk of bias, and extracted data from the included studies. The odds ratio (OR) and mean difference (MD) were calculated with a 95% confidence interval (CI) as a measure of the association between soy consumption and outcomes. We used a random-effects model to pool results across studies and the Grading of Recommendations Assessment, Development, and Evaluation to evaluate the certainty of evidence. We included eight studies in which 598 children consumed a soy-based diet but 2957 did not. The primary outcomes that could be plotted in the meta-analysis were the risk of PP and age at menarche. There was no statistical difference between groups for PP (OR: 0.51, 95% CI: 0.09 to 2.94, 3 studies, 206 participants, low certainty of evidence). No between-group difference was observed in menarche age (MD 0.14 years, 95% CI -0.16 to 0.45, 3 studies, 605 children, low certainty of evidence). One study presented this outcome in terms of median and interquartile range, and although the onset of menarche was marginally increased in girls who received a soy-based diet, the reported age was within the normal age range for menarche. We did not find any association between a soy-based infant diet and the onset of puberty in boys or girls. Trial Registration: PROSPERO registration: CRD42018088902.

Overweight is associated with early puberty in boys and girls

It has been clear that overweight and obesity in childhood is associated with onset of puberty at a younger age in girls. For boys, this has been less clear and study results have been variable. One issue is that defining onset of puberty may be more difficult in boys compared with girls. In this volume of The Journal, Chen et al used data from the Boston Birth Cohort Study to evaluate this question. They used age at peak height velocity as a marker of puberty. They found that overweight or obesity from age 2-7 years is associated with earlier onset of puberty in boys as well as in girls. However, those with overweight or obesity at age 2-4 years who became normal weight at age 5-7 had normal timing of puberty. This suggests that interventions to achieve normal weight from age 5-6 years could impact timing of puberty and avoid the deleterious impact of early onset of puberty. Article page 221 ▸ Trajectory of Body Mass Index from Ages 2 to 7 Years and Age at Peak Height Velocity in Boys and GirlsThe Journal of PediatricsVol. 230PreviewTo examine the associations between body mass index (BMI) at 2-4 years and 5-7 years and age at peak height velocity (APHV), an objective measure of pubertal timing, among boys and girls from predominantly racial minorities in the US that have been historically underrepresented in this research topic. Full-Text PDF

Low BMI, but not high BMI, influences the timing of puberty in boys.

Previous studies investigating the association between weight status and onset of puberty in boys have been equivocal. It is currently unclear to what extent weight class influences puberty onset and progression. To explore the relationship between degree of sexual maturation and anthropometric measures in Norwegian boys. The following endpoints were collected in a Norwegian cross-sectional study of 324 healthy boys aged 9-16: ultrasound-determined testicular volume (USTV), total serum testosterone, Tanner pubic hair stage, height, weight, waist circumference (WC), subscapular skinfolds (SSF), and body fat percentage (%BF). Testicular volume-for-age z-scores were used to classify "early," "average," or "late" maturing boys. Ordinal logistic regression analyses with a proportional odds model were applied to analyze the association between anthropometric variables and age-adjusted degree of pubertal development, with results expressed as age-adjusted odds ratios (AOR). Cumulative incidence curves for reaching pubertal milestones were stratified by BMI. Boys with a low BMI for age (BMIz <-1) were less likely to have reached a pubertal testicular volume (USTV≥2.7mL) or a pubertal serum level of testosterone (≥0.5nmol/L) compared to normal weight boys (AOR 0.3, p=0.038, AOR 0.3, p=0.026, respectively), and entered puberty on average with a delay of approximately eight months. Boys with high BMI for age (BMIz >1) exhibited a comparable timing as normal weight boys. The same was found for WC. Pubertal markers were not associated with SSF or %BF. By examining the association between puberty and weight status classified as low, average, or high, we found that a low BMI or WC for age were associated with a less advanced pubertal development and delayed timing of puberty in boys. No significant association was observed for a high BMI or WC. Moreover, no significant effects of SSF or %BF were observed. A low weight status should also be considered when assessing pubertal development in boys.

Exposure to Perfluoroalkyl Substances during Fetal Life and Pubertal Development in Boys and Girls from the Danish National Birth Cohort.

Background:It remains unsettled whether prenatal exposure to perfluoroalkyl substances (PFASs) affects human reproductive health through potential endocrine disruption.Objectives:We aimed to explore the associations between prenatal exposure to several PFASs and various aspects of pubertal development in boys and girls.Methods:We studied two samples ( and 445) from the Puberty Cohort, nested within the Danish National Birth Cohort (DNBC), measuring PFAS in maternal plasma from early gestation. Data on pubertal development were collected biannually from the age of 11 y until full maturation, using web-based questionnaires. Outcomes were age at menarche, voice break, first ejaculation, and Tanner stages 2 to 5 for pubic hair, breast, genital development, and a combined puberty indicator. A regression model for censored data was used to estimate mean difference (months) in age at achieving the pubertal outcomes across tertiles of PFAS concentrations and with a doubling of PFAS concentrations (continuous). For perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), a meta-analysis was used to provide a weighted average of the point estimates from samples 1 and 2.Results:Overall, prenatal exposure to PFOS, perfluorohexane sulfonate (PFHxS), perfluoroheptane sulfonate (PFHpS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PDFA) (girls) and PFHxS and PFHpS (boys) was associated with lower mean age at puberty marker onset. PFDA and PFNA exposure was associated with higher mean age at onset of puberty in boys. Nonmonotonic associations in girls (PFOS, PFHpS, PFDA) and boys (PFDA, PFNA) were observed, showing larger mean age differences for the combined puberty indicator in the middle tertile [girls: PFOS: mo, 95% confidence interval (CI): , ; PFHpS: mo, 95% CI: , 1.85; PFDA: mo, 95% CI: , 1.83; and boys: PFNA: 4.45 mo, 95% CI: , 10.21; PFDA: 4.59 mo, 95% CI: , 10.11] than in the highest tertile with the lowest as reference.Conclusions:Our population-based cohort study suggests sex-specific associations of altered pubertal development with prenatal exposure to PFASs. These findings are novel, and replication is needed. https://doi.org/10.1289/EHP3567

Параллели физического и полового развития у мальчиков в дебюте пубертата, проживающих в йододефицитном регионе

Параллели физического и полового развития у мальчиков в дебюте пубертата, проживающих в йододефицитном регионе

Association between Small Fetuses and Puberty Timing: A Systematic Review and Meta-Analysis.

Background: Epidemiological studies reporting the effect of small fetuses (SF) on puberty development have shown inconsistent results. Objective: To examine current study evidence and determine the strength and direction of the association between SF and puberty timing. Methods: PubMed, OVID, Web of Science, EBSCO, and four Chinese databases were searched from their date of inception to February 2016. All cohort studies that examined the association between SF and puberty timing in children were identified. Two reviewers independently screened the studies, assessed the quality of included studies, and extracted the data. The quality of the included cohort studies was assessed by the Newcastle–Ottawa Scale. Risk ratio (RR), Weighted Mean Difference (WMD), and 95% confidence intervals (CIs) were calculated and pooled by RevMan5.3 (Cochrane Collaboration, London, UK). Results: A total of 10 cohort studies involving 2366 subjects was included in the final analysis. The pooled estimates showed that SF did not significantly increase the number of pubertal children in boys (RR: 0.97; 95% CI: 0.82 to 1.15), or in girls (RR: 0.91; 95% CI: 0.79 to 1.04). Compared with the control group, the SF group had an earlier onset of puberty in girls (WMD: −0.64; 95% CI: −1.21 to −0.06), and in precocious pubarche (PP) girls (WMD: −0.10; 95% CI: −0.13 to −0.07). There was no difference in the onset of puberty in boys (WMD: −0.48; 95% CI: −1.45 to 0.50) between SF and control groups. The pooled result indicated an earlier age at menarche in girls born small for gestational age (WMD: −0.30; 95% CI: −0.58 to −0.03), but no difference in the age at menarche in the SF group of PP girls. Conclusions: SF may be associated with an earlier age of onset of puberty, especially among girls, as well as earlier age at menarche for girls. Well-designed studies with larger sample sizes and long-term follow-up among different countries and ethnicities are needed.

Relationships of Pyrethroid Exposure with Gonadotropin Levels and Pubertal Development in Chinese Boys.

Although an acceleration of male pubertal development has been observed, precisely which endocrine-disrupting chemicals (EDCs) might contribute to the advancing onset of puberty in boys remains unclear. Here, pyrethroids, a class of widely used insecticides that have been considered as EDCs, are proposed as new environmental risk factors. In this study, 463 boys at the age of 9-16 years old were recruited in Hangzhou, Zhejiang, China. The common metabolites of pyrethroids, 3-phenoxybenzoic acid (3-PBA), and 4-fluoro-3-phenoxybenzoic acid (4-F-3-PBA), as well as gonadotropins, including luteinizing hormone (LH) and follicle-stimulating hormone (FSH), were analyzed in urine samples. Pubertal development was assessed based on Tanner stages and testicular volume (TV). A positive association between 3-PBA and gonadotropins was found (p < 0.001), in which a 10% increase in 3-PBA was associated with a 2.4% and 2.9% increase in LH and FSH, respectively. Higher urinary levels of 3-PBA in boys were associated with 275% and 280% increase in the risk of being genitalia stage 3 (G3) and G4, respectively (p < 0.05). There was a significant (132%) induction in odd of being TV 12-19 mL with increasing 3-PBA concentration compared to being in TV < 4 mL (p < 0.05). For the first time to our knowledge, this work reports on an association of increased pyrethroid exposure with elevated gonadotropins levels and earlier pubertal development in boys.

Effect of Weight Loss on Puberty Onset in Overweight Children

To assess the impact of weight changes on the onset of puberty in overweight children. We evaluated the timing of puberty onset in 160 prepubertal overweight children (aged 11.2 ± 1.0 years) depending on the changes of their weight status in a 1-year lifestyle intervention. We determined body mass index (BMI), pubertal stage, luteinizing hormone (LH), follicle-stimulating hormone, insulin-like growth factor (IGF)-1, insulin-like growth factor binding protein-3, insulin resistance index homeostatic model assessment, and serum gonadotropins at baseline and 1 year later. Puberty onset during the 1-year follow-up was significantly (P = .014) more frequent in girls without BMI-SDS reduction (75.0%) compared with girls with BMI-SDS reduction (45.7%). The start of puberty was significantly (P = .024) more frequent in boys with BMI-SDS reduction (76.9%) compared with boys without BMI-SDS reduction (53.6%). In logistic regression analyses adjusted for baseline age and BMI-SDS, BMI-SDS reduction was associated with a decreased likelihood for puberty onset in girls (OR 0.24; 95% CI 0.07-0.85) and an increased likelihood in boys (OR 3.77; 95% CI 1.34-10.52). Central onset of puberty was confirmed by an increase of LH concentration and LH/follicle-stimulating hormone ratio in both boys and girls. Homeostatic model assessment, IGF-1, and IGF-1/insulin-like growth factor binding protein-3 ratio as marker for free IGF-1 at baseline or their changes were not associated with the onset of puberty. BMI-SDS reduction in overweight children was associated with earlier gonadotropin-dependent onset of puberty in boys and later onset of puberty in girls, suggesting earlier puberty in obese girls and later puberty in obese boys. We found no evidence that insulin resistance or IGF-1 have an impact on the start of puberty in obese children. ClinicalTrials.gov: NCT00435734.

Assessment of Sexual Maturation among Boys in Special Schools of Tehran, Iran

Background: Due to lack of detailed standards of sexual maturity in individuals with Intellectual, sensory and motor disability in Iran and the importance of timing of onset of puberty in these individuals, a study is necessary. By knowing the onset of puberty, physiologic and behavioral changes can be traced in these people, as well as the potential impact of the puberty on the underlying disease can be considered. The aim of the study was to investigate of sexual maturation among boys of special schools of Tehran. Materials and Methods: Cross-sectional study was performed on children and adolescents male students in special school in Tehran at 2013. A random, multistage sample 0f 895 boy students of special schools was taken from 25 special schools in five districts of Tehran city. In this study, symptoms and stages of puberty were identified. Pubertal stages were assessed by visual inspection and palpation based on the rating scales of Tanner. In addition, demographic data such as age, height, weight were collected. Then the data were analyzed and mean age of onset of puberty was determined. Results: The mean age of onset of puberty in boys (Genitalia stage 2) was 13.12 ± 1.84 years and sexual maturation was completed at 16.57 ± 1.34 years. The average height at the onset of puberty (Genitalia stage 2) was 151.1 ± 9.91 cm and the average weight was 48.47 ± 10.14kg. The mean BMI for puberty onset was 20.89 ± 5.43. Conclusion: In our study, the mean age of puberty onset in boys with disabilities was 13.12 ± 1.84 years. Compared to the data from healthy boys, our findings indicate that the mean age of pubertal onset in boys with disabilities in special school is higher than that of their healthy counterparts.

Pubertal Development

Pubertal Development

Pubertal Onset in Boys and Girls Is Influenced by Pubertal Timing of Both Parents.

Epidemiological evidence on maternal and paternal heritability of the wide normal variation within pubertal timing is sparse. We aimed to estimate the impact of parental pubertal timing on the onset of puberty in boys and girls. Annual pubertal examinations of healthy children in a longitudinal cohort study. Information on parental timing of puberty (earlier, comparable to, or later compared to peers) and menarche age was retrieved from questionnaires. A total of 672 girls and 846 boys. Age at onset of pubic hair (PH2+), breasts (B2+), and menarche in girls; and PH2+, genital stage (G2+), and testis >3 mL with orchidometer (Tvol3+) in boys. In boys, pubertal onset was significantly associated with pubertal timing of both parents. PH2+ and Tvol3+ were earlier: -11.8 months (95% confidence interval, -16.8, -6.8)/-8.9 (-12.8, -4.9), and -9.5 (-13.9, -5.1)/-7.1 (-10.4, -3.7) if the father/mother, respectively, had early pubertal development compared to late. In girls, menarche was significantly associated with both parents' pubertal timing: -10.5 months (-15.9, -5.1)/-10.1 (-14.3, -6.0) if father/mother had early pubertal development compared to late. For the onset of PH2+ and B2+ in girls, estimates were -7.0 months (-12.6, -1.4) and -4.1 (-10.6, +2.4)/-6.7 (-11.0, -2.5), and -6.7 (-11.0, -2.0) for fathers/mothers, respectively. Maternal age of menarche was significantly associated with the onset of all pubertal milestones except PH2+ in girls. Maternal as well as paternal pubertal timing was a strong determinant of age at pubertal onset in both girls and boys. Age at breast and pubic hair development in girls, which has declined most during recent years, seemed to be least dependent on heritability.

Primary Adrenal Insufficiency in a Newborn With Adrenal Hypoplasia Congenita Caused by a Mutation of theDAX1Gene

Adrenal hypoplasia congenita (AHC) is a rare inherited disorder of the adrenal gland caused by deletion or mutation of the dosage-sensitive sex-reversal AHC critical region on the X chromosome, gene 1 (DAX1) gene. The DAX1 gene is expressed in the adrenal cortex, the pituitary gland, the hypothalamus, the testis, and the ovary. Most affected infants present with failure to thrive, salt wasting, and hypoglycemic seizure in early life. Immediate mineralocorticoid and glucocorticoid replacement is essential. Most boys with AHC present with hypogonadotropic hypogonadism, resulting in failure to enter puberty and the need for testosterone treatment. However, a recent study revealed that the onset of puberty in boys with AHC can be variable, ranging from arrested or absent to precocious. We describe a case involving a newborn who presented with primary adrenal insufficiency due to a mutation of the DAX1 gene and was finally diagnosed with AHC.

Contemporary Trends in Onset and Completion of Puberty, Gain in Height and Adiposity.

Recent studies have documented earlier pubertal maturation in both girls and boys. Several factors have been proposed to account for earlier maturation. Epidemiologic studies have indicated that genetic factors are the most important influence contributing to the variability in the onset of puberty. Studies have also noted the association of elevated BMI with earlier puberty in girls, although the relationship between BMI and onset of puberty in boys is less consistent. The relationship of BMI and onset of puberty may be mediated by several factors, including leptin and kisspeptin, changes in bioavailable sex hormones, and environmental exposures. Recently, there have been genome-wide meta-analyses examining onset of puberty and anthropometric traits that may provide insight into the relationships of BMI, height velocity, and pubertal timing. Newer fields of investigation include examination of epigenetic modification.

Nutrition and pubertal development.

Nutrition is one of the most important factors affecting pubertal development. Puberty entails a progressive nonlinear process starting from prepubescent to full sexual maturity through the interaction and cooperation of biological, physical, and psychological changes. Consuming an adequate and balanced healthy diet during all phases of growth (infancy, childhood and puberty) appears necessary both for proper growth and normal pubertal development. Girls begin puberty at an earlier age compared to past decades. Excessive eating of many processed, high-fat foods, may be the cause of this phenomenon. Overweight or obese children are more likely to enter puberty early. Some evidence suggests that obesity can accelerate the onset of puberty in girls and may delay the onset of puberty in boys. Moreover, the progression of puberty is affected by nutrition. On the other hand, puberty triggers a growth spurt, which increases nutritional needs including macro and micronutrients. Increased caloric, protein, iron, calcium, zinc and folate needs have to be provided during this critical period of rapid growth. Severe primary or secondary malnutrition also can delay the onset and progression of puberty. The higher incidence of anorexia nervosa and bulimia in adolescents imposes a nutritional risk on pubertal development. Moreover, many environmental endocrine disruptors (EDs) have been identified that can significantly impair the normal course of puberty. This mini-review sums up some important findings in this important complex that link nutrition and pubertal development.

Stand der Pubertätsentwicklung bei Kindern und Jugendlichen während der kieferorthopädischen Therapie

Most orthodontic therapy in Germany takes place during puberty. However, since boys and girls experience puberty very differently, we can expect differences in their pubertal status when undergoing orthodontic therapy. In this study we addressed the stages of pubertal development in male and female children and adolescents undergoing orthodontic treatment. A total of 1011 individuals were randomly selected from a population-based representative sample of school students aged 10-18 years in the German city of Halle/Saale. This cohort was evaluated for the prevalence of orthodontic treatment and--using a modified German version of the Pubertal Development Scale--for pubertal status. An orthodontic subgroup of these boys and girls was analyzed for age distribution and pubertal stage (χ(2) test). The orthodontic subgroup included 296 boys and girls (accounting for 29.3% of the total sample), 50% of whom (n=148) had already attained advanced stages of pubertal development. Broken down by gender, we observed advanced stages in 60% of the girls versus 38% of the boys (p<0.001). However, this gender-specific difference was not reflected in the orthodontic subgroup's age distribution (p>0.05). Irrespective of gender, most subjects undergoing orthodontic treatment were 12 or 13 years old. Boys and girls in Germany undergo orthodontic treatment at the same age. Given the delayed onset of puberty in boys, most are still pre-pubertal, whereas most girls have reached an advanced stage of puberty by the time they undergo treatment--a discrepancy that could have therapeutic implications.

Progression of puberty after initiation of androgen therapy in patients with idiopathic hypogonadotropic hypogonadism

Background:Onset of puberty in boys usually occurs by 14 years of age. Some boys may exhibit delayed sexual maturation till about 17-18 years of age. However, pubertal onset beyond 18 years of age is exceedingly rare.Materials and Methods:Patients diagnosed as idiopathic hypogonadotropic hypogonadism (IHH) who had onset of puberty (increase in testicular volume >10 ml) while on androgen therapy were studied. These patients were evaluated prospectively.Results:There were nine subjects that were included in the study. The pre-therapy testicular volumes ranged from 3 to 6 ml. Luteinizing hormone (LH) levels increased from 1.2 ± 0.96 to 2.8 ± 1.0 IU/L, follicular stimulating hormone (FSH) levels increased from 1.5 ± 0.79 to 3.5 ± 1.9 IU/L, and testosterone increased from 0.36 ± 0.16 to 3.4 ± 2.1 ng/ml. Three out of nine patients had testosterone levels below 3 ng/ml.Conclusion:Our present study indicates that pubertal development can occur in patients presenting with hypogonadotropic hypogonadism after 18 years of age. However, acquired pubertal status may be subnormal

Premature Birth and Age at Onset of Puberty

Premature birth is associated with poor metabolic health in both sexes, potentially via earlier pubertal timing. We examined the associations of gestational age and premature birth (< 37 weeks gestation) with age at onset of puberty (Tanner stage II for breast or genitalia development). We used interval-censored survival analyses in 3963 boys and 3403 girls (93% follow-up) in a population-representative Chinese birth cohort, "Children of 1997," comprising 88% of births in Hong Kong in April and May 1997. We also examined whether the associations varied with sex or with height or body mass index (BMI) at 7 years. Premature girls reached puberty about 4 months later than girls with ≥ 41 weeks' gestation (time ratio = 1.04 [95% confidence interval = 1.01-1.06]), adjusted for mother' age of menarche, mother's place of birth, and smoking during pregnancy. Gestational age was not associated with onset of puberty in boys (test for interaction by sex, P < 0.01). None of these associations was altered by adjustment for socioeconomic position or varied with childhood height or BMI. Premature birth was not related to earlier onset of puberty; instead, premature girls had later onset of puberty. Thus, the association between premature birth and subsequent cardiovascular risk is probably not mediated through the timing of pubertal onset. It is unclear whether onset, duration, or tempo of puberty is more relevant to the detrimental consequences of early puberty. Further studies investigating intrauterine, infant, and childhood influences on the duration and tempo of puberty may help unravel the early origins of cardiovascular diseases.