Pubertal characteristics among schoolgirls in Riyadh, Saudi Arabia

Puberty is the gradual transition period between childhood and adulthood. Many factors may contribute to the onset of puberty. The objective of the study was to determine the age of onset of secondary pubertal characteristics among Saudi Arabian girls. A cross-sectional study was conducted using a cluster sample design. Seven hundred and twenty-five schoolgirls between the ages of 6 and 16 years from diverse socioeconomic levels were included. During physical examinations, the height and weight of the girls were recorded, and the stages of breast and pubic hair development were determined according to Tanner stages; axillary hair development was determined according to modified stages. The median age at Tanner stage 2 for breast and pubic hair development was 10 years. The median age at stage 2 in modified scales for axillary hair development was 12 years. In conclusion, the median age of the onset of breast development at Tanner stage 2 for Saudi girls in Riyadh is lower than what has been reported in some countries in Europe, South Africa, Turkey and India but similar to girls in Hong Kong, China and white girls in the USA, which may support secular trends of an earlier onset of puberty.     

Pubertal maturation in girls and the relationship to anthropometric changes: pathways through puberty

OBJECTIVE: Patterns of pubertal maturation may have an impact on several risk factors associated with adult morbidity and mortality, such as obesity. We examined the relationship of the initial manifestation of puberty in girls with anthropometric measures, as well as age at menarche. METHODS: White females (n = 1166, ages 9 and 10 at intake) were followed with annual visits for 10 years. Physical examinations included height, weight, skinfold thicknesses, and pubertal maturation assessment. RESULTS: During the course of the study, 443 of 859 eligible females (51.6%) were observed to have asynchronous maturation in the development of puberty, that is, initial areolar/breast (thelarche pathway) or pubic hair (adrenarche pathway) development, without development of the other characteristic. Using a longitudinal regression model, significant interactions were noted between initial pubertal manifestation and years since onset of puberty on the following outcomes: sum of skinfolds thickness, percent body fat, waist-to-hip ratio, and body mass index (BMI). However, age of onset of pubertal maturation was the same in the 2 groups (10.7 years). Females in the thelarche pathway had earlier menarche (12.6 vs 13.1 years) as well as greater skinfolds, body fat, and BMI at the time of menarche. Females in the thelarche pathway also had greater body fat and BMI 1 year before puberty and throughout puberty compared with those in the adrenarche pathway. CONCLUSIONS: Females who enter puberty through the thelarche pathway, as compared with the adrenarche pathway, had greater sum of skinfold thicknesses, BMI, and percent body fat 1 year before the onset, as well as throughout, puberty. Because larger body composition and earlier age of menarche of females in the thelarche pathway parallel the epidemiologic profiles of women who are obese or at risk for obesity, these females may be at greater risk for adult obesity.     

A mixed-longitudinal study on the pattern of pubertal growth: relationship to socioeconomic status and caloric-intake--IV

The pubertal growth pattern was observed on 791 girls belonging to upper and low SES. These girls ranged between 7-16 years. The effect of calorie intake on the pubertal growth was also ascertained. The development of breast was first to appear at the age of 8.25 years. It was followed by pubic and axillary hair development. The mean age of menarche was 12 years and 12.8 years for USES and LSES, respectively. The onset of menarche, breast and pubic hair was significantly delayed in LSES girls by 0.8 years. Menarche was found to correlate better with breast development than pubic or axillary hair. The girls on adequate calories showed early onset of breast, pubic hair and axillary hair development and of menarche. Similarly, these girls attained mature stage (adult) of these variables earlier compared to those who were on inadequate calories. However, intermittent developmental stages of pubic hair and axillary hair showed no consistency with intake of calories. The girls on inadequate calories showed approximately one year late onset of breast and pubic hair development. The present observations suggest that the onset of puberty is strongly influenced by environment but its attainment is under the genetical control.     

Breast contact thermography for differentiation between premature thelarche and true precocious puberty

Breast contact thermography was used to differentiate between premature thelarche and true precocious puberty. The technique was applied to 10 girls with premature thelarche, 12 with precocious puberty and 105 controls (Tanner B1-5). In controls, the scores attributed to the maturative thermographic signs correlated with breast development stages. In premature thelarche thermographic signs of vascularization were always absent, while in precocious puberty they were always observed, although in some cases unilaterally. The thermographic index (higher total score between the two breasts) ranged from 0 to 3 in girls with premature thelarche and from 4 to 10 in girls with precocious puberty. The thermographic pattern in premature thelarche was similar to that in prepubertal girls and did not progress in two girls who were repeatedly examined. We emphasize the useful role of contact thermography in evaluating pubertal breast development and in differentiating between premature thelarche and true precocious puberty.Abbreviations BCT breast contact thermography - TI thermographic index - B breast development stage - F fundus - N nipple - A areolar zone - V vascular growth pattern     

Hormonal changes in girls with precocious adrenarche: a possible role for estradiol or prolactin.

Serum concentrations of dehydroepiandrosterone, DHA sulfate, estradiol, and prolactin in 20 girls with precocious adrenarche were compared with those of healthy girls of varying age and degrees of breast and sex hair development. Production of adrenal androgens, as reflected by serum DHA and DHA-sulfate concentrations, was significantly increased in PA above that in age-matched control subjects. Surprisingly, in spite of their lack of breast growth, the patients with PA also had serum estradiol levels that were higher than in the prepubertal girls and similar to those found in girls with both breast and pubic hair development. Serum prolactin concentrations in the patients with PA were not increased over those of the age-matched (less than 8 years) prepubertal girls. In the older prepubertal ( greater than 8 years) and early pubertal girls serum prolactin levels were lower. The finding of increased estradiol levels suggests that precocious adrenarche is not a distinct endocrine entity, but merely represents a variant of early adolescence in which estrogen secretion is sufficient to influence adrenal 3beta-hydroxysteroid dehydrogenase activity with a resultant rise in DHA production, but not sufficient to produce clinically apparent breast changes. The data do not support a similar role for prolactin.     

Premature Thelarche in Later Childhood Demonstrates a Pubertal Response to GnRH Stimulation Test at One Year after Breast Development

Premature thelarche in later childhood (such as at 5–7 yr of age) is not always easy to distinguish from GnRH-dependent precocious puberty. In this study, a GnRH stimulation test was performed on 21 girls from 5 to 7.5 yr of age with early breast development. In 8 of 11 girls within 1 yr after thelarche, i.e., breast development, the GnRH stimulation test showed a prepubertal response, and in all 10 girls at more than 1 yr after breast development, the GnRH stimulation test showed a pubertal response. In observations of 4 girls with a prepubertal response, the GnRH stimulation test showed to a pubertal response by 1 yr or more after breast development in 3 of 4 the girls. These results indicate the possibility that almost all cases of breast development in later childhood consist of premature thelarche and that premature thelarche in later childhood may easily lead to early puberty at 1 yr or more after breast development. Careful observations are therefore recommended for at least 1 yr, even if early breast development is considered to be associated with premature thelarche in later childhood.     

Pubertal stages 1980 of Stockholm schoolchildren

In March 1980 a cross-sectional study of the pubertal development of a sample of Stockholm schoolchildren was conducted. Breast development (B1-B5), pubic hair (PH1-PH5) and axillary hair (AH1-AH3) were rated in 138 girls, and genitalia development (G1-G5), pubic hair (PH1-PH5) and axillary hair (AH1-AH3) were rated in 116 boys according to the Tanner method. The girls'and the boys'ratings were done by one female and one male medically qualified expert respectively. When relating social class to age of pubertal stage no significant differences were found. Median ages for entry to successive pubertal stages as well as centiles were calculated by logistic regression. Girls were somewhat earlier in their breast and pubic hair development than Stockholm girls investigated in earlier studies; however, somewhat later in their development of axillary hair. The boys entered G2 earlier than boys studied in 1970 but entered G5 at exactly the same age, 15.1 years. Boys entered PH2 somewhat later than 1970 boys, but again reached PH5 at exactly the same age, 15.5 years. The present study is based on a more recent and somewhat larger sample of children drawn from a wider area of Stockholm than the earlier studies. It is therefore suggested that these values be used in the proposed new height and weight reference values for youth in Sweden.     

Pubertal development in Swiss girls

Pubertal development between 8 and 18 years is reported in 142 Swiss females of the First Zurich Longitudinal Study (1954-1980). Genital and pubic hair development were rated according to TANNER [9]. Pubertal development was initiated at the earliest between 8 and 9 years and at the latest between 14 and 15 years of age. The first secondary sex character in 53% of the girls was the onset of pubic hair development and in 18% the onset of breast development. In 29% both the initiation of breast and that of pubic hair development were observed as the first pubertal signs. Pubertal development was completed at the earliest between 12 and 13 years and at the latest between 17 and 18 years of age. Most pubertal stages of breast and pubic hair development tended to be reached at earlier ages than previously reported. Omissions of stages occurred only in a few percent of the girls. A notable exception was breast stage 4 which was absent in 33%. Reversions of stages, particularly of breast stage 5 to a lower breast stage, were occasionally observed. The mean duration of breast development was 3.2 +/- 1.4 years and pubic hair development 3.6 +/- 1.1 years. The mean age at menarche was 13.4 +/- 1.0 years. Menarche was reached on the average 2.2 years after the initiation of breast development and 2.7 years after the initiation of pubic hair development. In spite of large variations in timing and duration of pubertal stages some significant relationships were noted between the pubertal characters. Moderate correlations were found between the ages at initiation of breast and pubic hair development and menarche. The ages at completion of breast and pubic hair development, menarche and the age at which the peak of the adolescent growth spurt (PHV) was reached were highly correlated with each other. There was no significant relationship between the duration of breast development and that of pubic hair development. Furthermore, no clear relationship between the timing of pubertal development and its duration could be established. In contrast to previous reports the temporal relationship between pubertal development and the adolescent growth spurt was found to be similar in both sexes.     

Somatic puberty development in girls

In 142 Swiss girls of the First Zurich Longitudinal Study. The somatic pubertal development between 9 and 18 years is described. The mean chronological age at the onset of the pubertal growth spurt was 9.6 years (standard deviation 1.2 years). The peak of the pubertal growth spurt (peak height velocity: PHV) was reached at a mean age of 12.2 years (SD 1.0). The development of pubic hair started at a mean age of 10.4 years (SD 1.2), breast development at 10.9 years (SD 1.2) and the development of axillary hair at 12.0 years (SD 1.1). Menarche occurred 2.7 years (SA 1.1) after the initiation of pubic hair development and 2.2 years (SD 1.1) after the breast development had started. Menarche was noted at a mean age of 13.4 years (SA 1.1). At menarche the mean height was 156.9 cm (SD 6.3), the mean weight 45.5 kg (SD 6.8) and the mean bone age (according to Greulich and Pyle) 12.6 years (SD 0.8). With the onset of menarche 95.3% (SD 1.7) of adult height were reached; the corresponding remaining height gain was 7.8 cm (SD 2.8). Acne was observed in 81% and striae in 41% of the girls by 18 years.     

Assessment of pubertal development in Egyptian girls

Puberty is a significant event of human growth and maturation associated with marked physiological and psychological changes. The aim of this study was to assess normal pubertal development in Egyptian girls to define normal, precocious and delayed puberty. The present study included a cross-sectional sample of 1,550 normal Egyptian girls of high and middle socioeconomic class living in Cairo. Their ages ranged from 6.5 to 18.5 years. Pubertal assessment was made according to Tanner staging. The mean menarcheal age (MMA) was estimated using probit analysis. Weight and height were measured and body mass index (BMI) was calculated. The mean age at breast bud stage (B2) was 10.71+/-1.6, pubic hair stage (PH2) was 10.46+/-1.36, while axillary hair stage (A2) was 11.65+/-1.62 and MMA was 12.44 years. The mean age at attainment of puberty was compared with those of other Egyptian studies and other populations. Girls of the present study started pubertal development and achieved menarche earlier than those of previous Egyptian studies confirming a secular trend. Differences between the present study and other worldwide studies can be attributed to various genetic, racial, geographical, nutritional, and secular trend factors.     

Pelvic ultrasonography in normal girls and in girls with pubertal precocity

This prospective study sought to evaluate the role of pelvic ultrasonography in differentiating between various types of pubertal precocity. A control group of 117 normal girls (aged 1.1-15.6) was studied and compared with 87 girls with premature sexual maturation (aged 1.1-9.2y). Of these patients 19 had central precocious puberty (CPP), 48 had isolated premature thelarche (IPT) and 20 had premature adrenarche (IPA) Pelvic ultrasound variables evaluated were: (i) uterus: longitudinal diameter (uterine length), cross-sectional area (CSA) and fundo-cervical ratio; and (ii) ovaries: volume and morphology. Ovarian morphology was subdivided in 6 different appearances: solid, microcystic, paucicystic, multicystic, macrocystic, and major isolated cyst. In normal control girls, uterine length and CSA increased with age, although no cut-off values could be defined between different age ranges, and they were correlated with breast stage; fundo-cervical ratio was stable through childhood and increased after age 9. Ovarian volume was significantly greater in pubertal girls with breast stage 2 than in those with only pubic and/or axillary hair. There was a clear predominance of solid ovarian appearances in the age range 2-7, with the multicystic appearance being seen only after age 7, a minority being macrocystic. After age 10 all the different patterns were observed, and after age 13 the frequency of a macrocystic pattern increased. Significantly more mature ovarian appearances were observed in subjects with breast development compared with those without, independently of the presence of pubic hair. Patients with IPT had no significant differences in pelvic ultrasound measurements when compared with age-matched controls. All the different morphological ovarian appearances were observed in IPT, in contrast to age-matched controls, where only the less mature patterns (solid, micro- and paucicystic) were seen. Patients with CPP had significantly more mature patterns of ovarian morphology compared with age-matched controls, but did not differ from pubertal pre-menarcheal controls. Those patients with IPA differed from age-matched controls only in having significantly greater uterine length and CSA. Comparison of the pelvic ultrasound parameters between patient groups (IPT, CPP, IPA) and age-matched controls revealed significantly higher values in CPP for uterine length, uterine CSA and ovarian volume. Ovarian volume was also greater in IPT than in IPA. Ovarian morphology was significantly different in patients (IPT, CPP, IPA) compared with age-matched controls, but none of the ovarian morphological appearances was exclusive to a single condition. In conclusion: (i) pelvic ultrasound parameters increase progressively from birth to maturity, but no clear cut-off values can be established between age ranges; (ii) pelvic ultrasound variables reach adult values during puberty, with differences in the timing that may reflect geographical variations; (iii) the multicystic ovarian appearance occurs just before the onset of puberty; (iv) pelvic ultrasonography cannot always differentiate clearly between different disturbances of puberty and therefore cannot supersede other observations and investigations in the evaluation of pubertal disorders; and (v) in this study we propose a more detailed pelvic ultrasound terminology that can avoid apparent confusion in defining ovarian ultrasound appearance.     

The prevalence and risk factors of premature thelarche and pubarche in 4- to 8-year-old girls

Aim: To assess the prevalence of premature thelarche (PT) and pubarche in healthy 4‐ to 8‐year‐old girls and to investigate factors associated with early pubertal development. Method: Eight hundred and twenty girls were examined by two paediatric endocrinologists to determine Tanner staging. The effects of body mass index, gestational age, intrauterine growth status, age at the first tooth eruption, socio‐economical status, maternal age of menarche and consumption of certain food items on early pubertal development were analysed through parametric and nonparametric tests. Results: The prevalence of PT and of premature pubarche was 8.9% and 4.3%, respectively. We found a strong association between the prevalence of PT and the body mass index standard deviation scores (BMI SDS). There were more girls with BMI SDS values above 1 in the PT group (56.1%) than among the remaining subjects (22.9%). Premature thelarche was not significantly associated with intrauterine growth, premature birth, socioeconomic status, age of first tooth eruption or maternal age of menarche. Similarly, the amount of milk, eggs, chicken or fish consumed was not associated with PT. None of the investigated factors were associated with premature pubarche. Conclusion: Occurrence of PT is strongly associated with BMI SDS. Studies investigating secular trends in pubertal development must consider a secular change in body mass index.     

Pubertal Characteristics in Girls of Qazvin Province,Iran

Objective

Puberty is a critical time between childhood and adulthood. Many studies have reported that the mean age of breast development is decreasing. The aim of this study was to provide updated data on the pubertal development of girls and to evaluate precocious puberty in our population.

Methods

This cross sectional study was conducted in 6 to 16 year old school girls during 2009-2010 in Qazvin. 2240 healthy girls from all geographical regions with every socioeconomic status were selected by a stratified multistage cluster design to obtain representative sample of population. A questionnaire including demographic data, anthropometric measurements, secondary sexual characteristics, menarche status and its onset was filled out for every participant. Secondary sexual characteristics including breast development (B_1–5) and pubic hair (PH_1–5) were evaluated according to Marshal and Tanner recommendation.

Findings

The mean±SD of height, weight, and BMI of participants was 139.7±14.5, 36.1±12.9 and 17.9±3.7 respectively. The mean age (10th – 90th percentile) of B₂ and PH₂ were 9.71(7.67–11.4) and 9.82 years (7.84–11.42) respectively. Mean age of menstruation was 12.52 years. The mean BMI was significantly higher in pubertal females comparing to prepubertal girls (P<0.001). Average duration of puberty (the time from initiation of puberty to menarche) was 2.81 years.

Conclusion

The mean age of pubertal onset in girls living in Qazvin is 9.71 years. Menarche occurs at mean age of 12.52 and onset of puberty earlier than 6.24 years will be precocious. We found that girls in Qazvin had a slightly earlier age of initiation of puberty and of menarche in comparison with other studies in Iran.     

Acute gonadotropin response to the gonadotropin releasing hormone agonist (decapeptyl) in girls with pubertal pathology

The aim of the study was to assess the effect of a single injection of the GnRH agonist decapeptyl on gonadotropin secretion in girls with different pubertal disorders. The test was performed in two groups of girls with premature thelarche (younger and older than 2 years of age), girls with premature adrenarche and postmenarcheal girls with policystic ovaries. The GnRH agonist decapeptyl stimulated gonadotropins secretion in pre- and postmenarcheal girls. The responsiveness of LH was increased significantly in puberty. FSH response was exaggerated in the girls with premature thelarche before the age of 2, but in older premenarcheal girls with the same disorder it was not different than in girls with premature adrenarche. It is concluded that a single dose of the GnRH agonist decapeptyl is a safe and efficacious test for assessment of the function of the pituitary gland in pre-and postmenarcheal girls.     

Benign premature adrenarche: clinical features and serum steroid levels

18 girls with premature adrenarche were evaluated both clinically and by serum steroid measurements. Age at first appearance of the symptoms ranged from 3.0 to 7.8 years. Clinical findings included pubic or axillary hair, acne, accelerated growth, adult-type perspiration and oily skin or hair. Bone age was 0.3-3.2 years ahead of chronological age. 15 of these 18 girls had accelerated growth and most of these already before the appearance of pubic hair. Five girls had severe acne requiring topical treatment. Serum dehydroepiandrosterone was elevated for age in all patients. Androstenedione and testosterone correlated positively with the dehydroepiandrosterone values. Dihydrotestosterone was also elevated in many girls. Administration of dexamethasone brought about a rapid normalization of the elevated steroid levels.     

Premature pubarche as an indicator of how body weight influences the onset of adrenarche

Premature pubarche (PP) is defined as the development of pubic and/or axillary hair before the age of 8 years in girls and 9 years in boys. The objective was to obtain a clearer picture of the physiology of adrenarche by evaluating clinical-laboratory features of PP. The 216 consecutive children were classified according to their sex and age of onset of PP: PP occurred before 2 years in 21 girls and one boy, between 4 and 7.9 years in 162 girls and between 5 and 8.9 years in 28 boys. It occurred between 2 and 4 years in only four girls. The body mass index (BMI) was +2 SD in 2 children aged <2 years (9.1%), in 52 girls aged >4 years (32.5%) and in 13 boys aged >5 years (46.4%). The plasma dehydroepiandrosterone sulphate (S-DHEA) concentrations in children aged <2 years were lower than those expected in Tanner stage 2. They were higher in obese girls >4 years than in lean ones (P=0.009), with a positive correlation between S-DHEA and BMI z-score (P=0.004). Birth weights of girls >4 years were lower than those of the general population (P<0.01). Conclusion:premature pubarche is rare in boys. The cause in children aged <2 years is probably different than in older ones. Premature pubarche is associated with low birth weight in girls. The frequency of obesity and the correlation between dehydroepiandrosterone sulphate levels and body mass index suggest that body weight is involved in the onset of adrenarche.Abbreviations ACTH adrenocorticotropin - BMI body mass index - IUGR intrauterine growth retardation - PP premature pubarche - S-DHEA dehydroepiandrosterone sulphate - SD standard deviation     

北京市儿童青少年女性青春期性征发育流行病学研究

摘要 目的：了解北京市6~18岁学龄女生青春期第二性征发育现状,以及人群性早熟发生率。方法：利用2004年北京市儿童代谢综合征调查（BCAMS）总样本中9 778名6~18岁中小学女生的青春期发育数据，用概率单位回归法计算月经初潮、乳房、阴毛不同发育时期的中位年龄。8岁前乳房或阴毛发育达Tanner II 期（B2,P2），或10岁前月经初潮者被定义为性早熟。结果：9 778名6~18岁中小学女生中城市人口5 040人，占总样本51.5%。北京市学龄女生月经初潮年龄平均为 （12.1±1.1）岁，城市女生（11.9±1.1）岁，农村女生（12.5±1.1）岁；女性第二性征开始发育年龄（总体/城市/农村）分别为，乳房：（9.5±1.2）岁/（9.3±1.1）岁/(9.6±1.2）岁；阴毛:(11.1±1.1）岁/(10.8±1.1）岁/(11.4±1.1）岁。城市女生月经初潮、乳房和阴毛发育均显著早于农村女生。月经初潮早发生率为0.79%，城市高于农村（1.03%：0.55%；x2=6.93，P<0.01）；乳房、阴毛早发育率分别为2.91%和0.22%。1962~1982年期间，北京女生月经初潮年龄平均每10年提前0.7岁（8.4个月）；近10年平均提前0.43岁（5.2个月）。结论：北京市城区女生青春期第二性征发育明显早于郊区县女生。月经初潮年龄提前的长期变化趋势依然存在，但近10年这一趋势趋于减缓。     

BENIGN PREMATURE ADRENARCHE: CLINICAL FEATURES AND SERUM STEROID LEVELS

ABSTRACT. 18 girls with premature adrenarche were evaluated both clinically and by serum steroid measurements. Age at first appearance of the symptoms ranged from 3.0 to 7.8 years. Clinical findings included pubic or axillary hair, acne, accelerated growth, adult-type perspiration and oily skin or hair. Bone age was 0.3–3.2 years ahead of chronological age. 15 of these 18 girls had accelerated growth and most of these already before the appearance of pubic hair. Five girls had severe acne requiring topical treatment. Serum dehydroepiandrosterone was elevated for age in all patients. Androstenedione and testosterone correlated positively with the dehydroepiandrosterone values. Dihydrotestosterone was also elevated in many girls. Administration of dexamethasone brought about a rapid normalization of the elevated steroid levels.     

Premature adrenarche

Premature adrenarche refers to the precocious secretion of adrenal androgens, which results in the isolated development of pubic hair (pubarche) before the age of eight years in girls and nine years in boys. The female to male ratio is approximately 10:1. Dark, coarse and curly hair is limited initially to the labia majora in girls and to the root of the penis in boys. The hair extends gradually into the pubic region. Axillary hair, increased body odor, and acne can also be present. Hirsutism, deepening of the voice, clitoral enlargement, breast development, and phallic or testicular enlargement are characteristically absent. A transient acceleration of growth is common but final height is usually not affected. The onset of puberty usually occurs at the normal age. Premature adrenarche can be a forerunner of polycystic ovary syndrome and/or syndrome X. Continued observation and periodic re-evaluation is necessary.     

Declining age of puberty of school girls in southern Thailand

Background

Declines in the onset age of secondary sexual development have been reported in a number of recent studies in western and Asian countries. A study of Hat-Yai school girls in 1994 in Thailand showed that the ages at thelarche and menarche were 9.9 and 12.4 years, respectively. This study was to determine whether there was a decline in the average age of puberty in Hat-Yai school girls from 1994 to 2012.

Methods

A cross-sectional study was conducted in 2140 healthy Hat-Yai school girls, aged 6–18 years, from June 2011 to March 2012. Breast and pubic hair development was assessed by the Tanner staging method. Probit analysis was used to calculate the median ages of different stages of breast and pubic hair development, and the age of menarche.

Results

The median ages of girls having thelarche and menarche were 9.6 (95% CI, 9.4–9.8) and 12.2 (95% CI, 11.9–12.4) years, which declined from 9.9 (95% CI, 9.7–10.1) and 12.4 years (95% CI, 12.2–12.6) in the 1994 study respectively, however, without statistical significance. The youngest ages of girls who had breast stage 2 and menarche were 7.2 and 9.2 years, respectively. The final height at age 14 years in this cohort (157.3 cm) was 2.3 cm greater than that of girls in 1994 (155.0 cm).

Conclusions

From 1994 to 2012, the age at onset of thelarche and menarche of girls in Hat-Yai municipality declined by 0.2 and 0.3 years, respectively. The earlier age at onset of puberty had no effect on final adult height.