Comparison of clinical, ultrasonographic, and biochemical differences at the beginning of puberty in healthy girls born either small for gestational age or appropriate for gestational age: preliminary results

The Metabolic Programming of Pubertal Onset

BACKGROUND

There is increasing evidence that maternal factors such as nutritional status (both under and over-nutrition) and diabetes, alongside prenatal exposure to endocrine disrupting chemicals (EDCs), are associated with early pubertal onset in offspring. Such children are also at increased risk of the metabolic syndrome during adolescence and young adulthood.

AIM

This literature review focuses on the role of the prenatal environment in programming pubertal onset, and the impact of prenatal metabolic stressors on the declining average age of puberty.

METHOD

A review of all relevant literature was conducted in PubMed by the authors.

OUTCOME

The mechanism for this appears to be mediated through metabolic signals, such as leptin and insulin, on the kisspeptin-neuronal nitric oxide-gonadotropin releasing hormone (KiNG) axis. Exposed children have an elevated risk of childhood obesity and display a phenotype of hyperinsunlinaemia and hyperleptinaemia. These metabolic changes permit an earlier attainment of the nutritional "threshold" for puberty. Unfortunately, this cycle may be amplified across subsequent generations, however early intervention may help "rescue" progression of this programming.

Beyond defence: Immune architects of ovarian health and disease

Throughout the individual's reproductive period of life the ovary undergoes continues changes, including cyclic processes of cell death, tissue regeneration, proliferation, and vascularization. Tissue-resident leucocytes particularly macrophages, play a crucial role in shaping ovarian function and maintaining homeostasis. Macrophages crucially promote angiogenesis in the follicles and corpora lutea, thereby supporting steroidogenesis. Recent research on macrophage origins and early tissue seeding has unveiled significant insights into their role in early organogenesis, e.g. in the testis. Here, we review evidence about the prenatal ovarian seeding of leucocytes, primarily macrophages with angiogenic profiles, and its connection to gametogenesis. In the prenatal ovary, germ cells proliferate, form cysts, and undergo changes that, following waves of apoptosis, give rice to the oocytes contained in primordial follicles. These follicles constitute the ovarian reserve that lasts throughout the female's reproductive life. Simultaneously, yolk-sac-derived primitive macrophages colonizing the early ovary are gradually replaced or outnumbered by monocyte-derived fetal macrophages. However, the cues indicating how macrophage colonization and follicle assembly are related are elusive. Macrophages may contribute to organogenesis by promoting early vasculogenesis. Whether macrophages contribute to ovarian lymphangiogenesis or innervation is still unknown. Ovarian organogenesis and gametogenesis are vulnerable to prenatal insults, potentially programming dysfunction in later life, as observed in polycystic ovary syndrome. Experimental and, more sparsely, epidemiological evidence suggest that adverse stimuli during pregnancy can program defective folliculogenesis or a diminished follicle reserve in the offspring. While the ovary is highly sensitive to inflammation, the involvement of local immune responses in programming ovarian health and disease remains to be thoroughly investigated.

International Consensus Guideline on Small for Gestational Age (SGA): Etiology and Management from Infancy to Early Adulthood

This International Consensus Guideline was developed by experts in the field of SGA of 10 pediatric endocrine societies worldwide. A consensus meeting was held and 1300 articles formed the basis for discussions. All experts voted about the strengths of the recommendations. The guideline gives new and clinically relevant insights into the etiology of short stature after SGA birth, including novel knowledge about (epi)genetic causes. Besides, it presents long-term consequences of SGA birth and new treatment options, including treatment with gonadotropin-releasing hormone agonist (GnRHa) in addition to growth hormone (GH) treatment, and the metabolic and cardiovascular health of young adults born SGA after cessation of childhood-GH-treatment in comparison with appropriate control groups. To diagnose SGA, accurate anthropometry and use of national growth charts are recommended. Follow-up in early life is warranted and neurodevelopment evaluation in those at risk. Excessive postnatal weight gain should be avoided, as this is associated with an unfavorable cardio-metabolic health profile in adulthood. Children born SGA with persistent short stature < -2.5 SDS at age 2 years or < -2 SDS at age of 3-4 years, should be referred for diagnostic work-up. In case of dysmorphic features, major malformations, microcephaly, developmental delay, intellectual disability and/or signs of skeletal dysplasia, genetic testing should be considered. Treatment with 0.033-0.067 mg GH/kg/day is recommended in case of persistent short stature at age of 3-4 years. Adding GnRHa treatment could be considered when short adult height is expected at pubertal onset. All young adults born SGA require counseling to adopt a healthy lifestyle.

Bone age in prepubertal children with nonfamilial or familial idiopathic short stature and prepubertal short-stature children born small for gestational age: a longitudinal data analysis

This retrospective study aimed to clarify the characteristics of bone maturation using longitudinal data in short-stature prepubertal children. Children with chronological ages (CAs) of 4.5–10.5 yr with nonfamilial idiopathic short stature (ISS, n = 95), familial ISS (FSS, n = 21), and short-stature children born small for gestational age (SGA, n = 23) were selected, of which 435 left-hand plain radiographic images were evaluated. Bone age (BA) delay was defined as BA minus CA. In the ISS group, there was a statistically significant difference in median BA delay among the CA groups (P < 0.001), as median BA delay gradually increased from 5- to 9-yr-old groups (−1.06 [range, −2.17 to 0.27] and −2.45 [range, −4.35 to −0.32] yr, respectively). In the FSS group, median BA delays were approximately −1 yr in all CA groups. In the SGA group, median BA delay gradually decreased from 7- to 10-yr-old groups (−1.96 [range, −2.99 to 0.56] and −0.04 [range, −2.44 to 0.92] yr, respectively), but with no significant difference (P = 0.647). The heavier weight of children with FSS and the probable earlier onset of adrenarche in children born SGA compared to those with ISS could have affected bone maturation.

Early life exposure to famine and reproductive aging among Chinese women

OBJECTIVE

To assess the effect of early life exposure to famine, as endured during 1959 to 1961 in China, on reproductive aging in adult women.

METHODS

Between 2011 and 2012, 2,868 women born around the Chinese famine period (1956-1964) were enrolled in this study from three communities in China. Age at natural menopause was obtained retrospectively from a structured questionnaire. The associations of early life famine exposure with reproductive aging during adulthood were estimated, with adjustment of socioeconomic status, lifestyle factors, and body mass index.

RESULTS

Women exposed to prenatal famine had a higher risk of early menopause (ie, natural menopause <45 years, odds ratio: 1.59, 95% confidence interval [CI]: 1.07, 2.36), and a nonsignificant trend of higher risk of premature ovarian failure (ie, natural menopause <40 y, odds ratio: 1.94, 95% CI: 0.93, 4.00), compared to unexposed women. Exposure to famine during childhood was not significantly associated with reproductive aging. In a secondary analysis focusing on the fetal exposure, prenatal famine exposure was associated with a higher risk of premature ovarian failure (odds ratio: 2.07, 95% CI: 1.08, 3.87), and a nonsignificant trend of higher risk of early menopause (odds ratio: 1.37, 95% CI: 0.98, 1.91), compared to those unexposed to prenatal famine.

CONCLUSIONS

Our study showed that fetal exposure to famine was associated with an increased risk of early menopause. Such findings provided evidence in favor of the thrifty phenotype theory in reproductive aging and helped better understand the etiology of early menopause.

Sex Hormones, Gonad Size, and Metabolic Profile in Adolescent Girls Born Small for Gestational Age with Catch-up Growth

STUDY OBJECTIVE

To characterize and compare sex hormone concentrations, and uterine and ovarian volumes in adolescent girls born small for gestational age (SGA) who had experienced catch-up growth and girls born at a size appropriate for gestational age (AGA), and to investigate the association between these parameters and glucose metabolism, perinatal factors, and early growth.

DESIGN

A prospective, longitudinal, observational study from birth until adolescence.

SETTING

Mean age at final assessment was 12.7 ± 0.1 years.

PARTICIPANTS

We followed 55 girls (20 SGA, 35 AGA).

INTERVENTIONS AND MAIN OUTCOME MEASURES

Sex hormone concentrations (gonadotropins, estradiol, testosterone, and sex hormone binding globulin) were analyzed, and the oral glucose tolerance test conducted. Uterine and ovarian sizes were assessed using pelvic ultrasound.

RESULTS

Uterine and ovarian volumes were smaller in SGA-born compared with AGA-born girls (P = .013 and P = .039, respectively). SGA girls had lower sex hormone binding globulin levels (P = .039) and higher testosterone levels (P = .003), free androgen index (P < .001), and glycemia 2 hours post glucose load (P = .005) compared with AGA-born girls. Birth weight and early infancy height velocity explained 37.4% of variation in ovarian volume (P = .004), and body mass index at birth, increase in peripheral skinfold thickness during second year of life, and early childhood height velocity explained 43.2% of variation in testosterone levels in adolescence (P = .006).

CONCLUSION

SGA-born girls who experienced catch-up growth remain at risk of biochemical hyperandrogenism in adolescence, and have reduced uterine and ovarian volumes, which might influence future reproductive function. Ovarian size and androgen levels in adolescence might be influenced by early growth and subcutaneous fat deposition.

Relationship between final adult height and birth weight after gonadotropin-releasing hormone agonist treatment in girls with central precocious puberty

PURPOSE

The clinical significance of birth weight relative to gestational age in girls with central precocious puberty is unclear. This study sought to compare clinical parameters such as final adult height (FAH) and menarche onset after treatment with gonadotropin-releasing hormone agonist (GnRHa) on birth weight in girls with central precocious puberty treated.

METHODS

This retrospective study reviewed data of 69 girls with precocious puberty who had reached their FAH in a long-term trial of GnRHa treatment between January 2007 and December 2017. The subjects were divided into small for gestational age (SGA) (n=19) and appropriate for gestational age (AGA) (n=50) groups.

RESULTS

When starting GnRHa treatment, bone age was 10.9±0.9 and 10.3±0.8 years in the SGA and AGA groups, respectively (P&lt;0.05). The predicted adult height (PAH) (established according to the Bayley-Pinneau average table) and advanced PAH (established according to the Bayley-Pinneau advanced table) were 151.5±4.8 cm and 155.8±4.9 cm in the SGA group, respectively, and 153.4±5.3 cm and 159.0±6.0 cm in the AGA group. After treatment, no significant difference in bone age was found between the groups. The time to menarche after treatment was 12.5±7.6 and 21.1±12.3 months in the SGA and AGA groups, respectively (P&lt;0.05). FAH in the SGA and AGA groups was 161.0±4.7 cm and 161.6±5.0 cm, respectively, without a significant difference.

CONCLUSION

SGA girls with precocious puberty have increased bone age and earlier menarche relative to AGA girls. However, no difference in FAH after treatment was found between these groups.

What is the evidence for beneficial effects of growth hormone treatment beyond height in short children born small for gestational age? A review of published literature

Background An increasing body of evidence supports the view that both an adverse intrauterine milieu and rapid postnatal weight gain in children born small for gestational age (SGA) contribute towards the risk for the development of chronic diseases in adult life. Content The aim of this review was to identify and summarize the published evidence on metabolic and cardiovascular risk, as well as risk of impaired cardiac function, intellectual capacity, quality of life, pubertal development and bone strength among children born SGA. The review will then address whether growth hormone (GH) therapy, commonly prescribed to reduce the height deficit in children born SGA who do not catch up in height, increases or decreases these risks over time. Summary Overall, there are limited data in support of a modest beneficial effect of GH therapy on the adverse metabolic and cardiovascular risk observed in short children born SGA. Evidence to support a positive effect of GH on bone strength and psychosocial outcomes is less convincing. Outlook Further evaluation into the clinical relevance of any potential long-term benefits of GH therapy on metabolic and cardiovascular endpoints is warranted.

Maternal nutrient restriction impairs young adult offspring ovarian signaling resulting in reproductive dysfunction and follicle loss

Reproductive abnormalities are included as health complications in offspring exposed to poor prenatal nutrition. We have previously shown in a rodent model that offspring born to nutrient restriction during pregnancy are born small, enter puberty early, and display characteristics of early ovarian aging as adults. The present study investigated whether key proteins involved in follicle recruitment and growth mediate ovarian follicle loss. Pregnant rats were randomized to a standard diet throughout pregnancy and lactation (CON), or a calorie-restricted (50% of control) diet (UN) during pregnancy. Offspring reproductive phenotype was investigated at postnatal days 4, 27, and 65. Maternal UN resulted in young adult (P65) irregular estrous cyclicity due to persistent estrus, a significant loss of antral follicles, corpora lutea, and an increase in atretic follicles. This decrease in growing follicles in UN offspring appears to be due to increased apoptosis as seen by immunopositive staining of pro-apoptotic factor CASP3 (caspase 3) in ovaries of young adult offspring. UN prepubertal offspring had reduced expression levels of Fshr in antral follicles, which may contribute to a decrease in PI3K/AKT activation evident as a decrease in pAKT immunolocalization in prepubertal antral follicles. Moreover, neonatal ovaries of UN offspring show decreased levels of immunopositive staining for AMHR2 (anti-mullerian hormone receptor 2). Collectively, these data demonstrate that maternal UN during pregnancy impacts ovarian function in offspring as early as P65 and provides a model for understanding the mechanisms driving early life UN-induced follicle loss and reproductive dysfunction.

IUGR: Genetic influences, metabolic problems, environmental associations/triggers, current and future management

The children with intrauterine growth restriction (IUGR) especially if they make a catch-up growth in early life have a higher risk for long term problems including short stature and also developing metabolic syndrome, Type 2 diabetes, insulin resistance and cardiovascular diseases. The studies also support that these children may have abnormalities in pubertal timing, adrenarche and reproductive function. The aim of this review was to summarize the published reports mainly on puberty and reproductive functions in children born IUGR at older ages in association with metabolic problems that they encounter. Possible mechanisms explaining these outcomes are discussed. Lastly strategies that may be taken for the prevention of IUGR related morbidities at later life are shortly presented.

Long-term metabolic risk among children born premature or small for gestational age

Accumulating evidence suggests that both the intrauterine environment and growth during early life can influence the development of chronic noncommunicable diseases, such as type 2 diabetes mellitus and cardiovascular disease, in adulthood. Here, we review the available human data supporting increased metabolic risk among children born premature or small for gestational age; the adrenal and pubertal modifications that contribute to this risk; metabolic changes that occur during adolescence and early adulthood; and approaches to potentially modify or decrease risk of metabolic disease. The risks associated with delivery at term or preterm are compared for each period of life. Knowledge of these associations is fundamental for the paediatric community to develop preventive strategies early during postnatal life.

Low Birth Weight Is Associated with a Decreased Overall Adult Health Status and Reproductive Capability - Results of a Cross-Sectional Study in Primary Infertile Patients

Individuals born with low birth weight (LBW) risk cardiometabolic complications later in life. However the impact of LBW on general health status and male reproductive function has been scantly analysed. We investigated the clinical and seminal impact of different birth weights (BW) in white-European men presenting for primary couple's infertility. Demographic, clinical, and laboratory data from 827 primary infertile men were compared with those of 373 consecutive fertile men. Patients with BW ≤2500, 2500-4200, and ≥4200gr were classified as having LBW, normal (NBW), and high BW (HBW), respectively. Health-significant comorbidities were scored with the Charlson Comorbidity Index (CCI). Testicular volume was assessed with a Prader orchidometer. Semen analysis values were assessed based on 2010 WHO reference criteria. Descriptive statistics and regression models tested associations between semen parameters, clinical characteristics and BW categories. LBW, NBW and HBW were found in 71 (8.6%), 651 (78.7%) and 105 (12.7%) infertile men, respectively. LBW was more frequent in infertile patients than fertile men (p = 0.002). Infertile patients with LBW had a higher rate of comorbidities (p = 0.003), lower mean testicular volume (p = 0.007), higher FSH (p = 0.02) and lower tT levels (p = 0.04) compared to other BW groups. Higher rates of asthenozoospermia (p = 0.02) and teratozoospermia (p = 0.03) were also found in LBW men. At logistic regression models, LBW was univariably associated with pathologic progressive motility (p≤0.02) and pathologic sperm morphology (p<0.005). At multivariable logistic regression analysis, LBW achieved independent predictor status for both lower sperm motility and pathologic sperm morphology (all p≤0.04). Only LBW independently predicted higher CCI values (p<0.001). In conclusion, we found that LBW was more frequent in infertile than in fertile men. Infertile individuals with LBW showed a higher rate of comorbidities and significantly worse clinical, endocrine and semen parameters compared to other BW groups.

Leuprolide acetate-stimulated androgen response during female puberty

BACKGROUND

A physiological increase in androgen levels occurs during adolescence. Measuring androgen concentrations is the best method to distinguish normal evolution processes from hyperandrogenic disorders.

HYPOTHESIS

The increase in circulating androgens during puberty is inversely associated with insulin sensitivity in normal weight girls.

OBJECTIVE

To assess circulating levels of ovarian androgens and anti-Müllerian hormone (AMH) at baseline and after GnRH analogue (GnRH-a) stimulation in normal pubertal girls across different Tanner stages. We also studied the association between this response and insulin sensitivity.

DESIGN

Prospective study of healthy girls (6-12 years) from the local community (n = 63).

METHODS

Tanner I (n = 23) subjects were assessed cross-sectionally, and Tanner II girls (n = 40) were evaluated every 6 months until they reached Tanner V. Early morning dehydroepiandrosterone sulphate (DHEA-S), AMH, sex hormone-binding globulin (SHBG), androstenedione, glucose and insulin levels were measured. A GnRH-a test (500 μg/m(2) ; sc) and oral glucose intolerance test (OGTT) were performed. Differences throughout puberty were evaluated.

RESULTS

Basal and/or stimulated Testosterone DHEA-S and 17-hydroxyprogesterone (17OHP) were inversely associated with insulin sensitivity (WIBSI) from the beginning of puberty, whereas androstenedione was directly associated with gonadotrophins. AMH was inversely associated with basal and stimulated gonadotrophins and directly with insulin area under the curve (AUC) only in the early stages of puberty. 17OHP and testosterone responsiveness increased significantly during puberty in all subjects, whereas testosterone levels changed less consistently. This pattern of ovarian-steroidogenic response was most evident during mid- and late puberty. Moreover, during late puberty only, basal 17OHP, testosterone and DHEA-S were positively associated with gonadotrophins.

CONCLUSION

In normal nonobese girls born appropriate for gestational age, androgen synthesis was associated with insulin sensitivity in early puberty and with LH only in late puberty.

Early-life nutritional effects on the female reproductive system

There is now considerable epidemiological and experimental evidence indicating that early-life environmental conditions, including nutrition, affect subsequent development in later life. These conditions induce highly integrated responses in endocrine-related homeostasis, resulting in persistent changes in the developmental trajectory producing an altered adult phenotype. Early-life events trigger processes that prepare the individual for particular circumstances that are anticipated in the postnatal environment. However, where the intrauterine and postnatal environments differ markedly, such modifications to the developmental trajectory may prove maladaptive in later life. Reproductive maturation and function are similarly influenced by early-life events. This should not be surprising, because the primordial follicle pool is established early in life and is thus vulnerable to early-life events. Results of clinical and experimental studies have indicated that early-life adversity is associated with a decline in ovarian follicular reserve, changes in ovulation rates, and altered age at onset of puberty. However, the underlying mechanisms regulating the relationship between the early-life developmental environment and postnatal reproductive development and function are unclear. This review examines the evidence linking early-life nutrition and effects on the female reproductive system, bringing together clinical observations in humans and experimental data from targeted animal models.

Puberty in children born small for gestational age

Small for gestational age (SGA) children are more prone to have precocious pubarche and exaggerated precocious adrenarche, an earlier onset of pubertal development and menarche, and faster progression of puberty than children born of appropriate for gestational age (AGA) size. The majority of studies investigating the onset of puberty in children born SGA and AGA established that, although puberty begins at an appropriate time (based on chronological age and actual height) in SGA children, onset is earlier relative to AGA children. Evaluating pubertal growth in SGA children, a more modest bone age delay from chronological age at the onset of puberty and more rapid bone maturation during puberty compared to AGA children were reported. Peak height velocity in adolescence is reached at an earlier pubertal stage and lasts for a shorter period in children born SGA than in those born AGA. These differences lead to an earlier fusion of the growth plates and a shorter adult height. The pathophysiological mechanism underlying the unique pubertal growth pattern of children born SGA remains unclear. However, it seems that this is not only related to birth weight, gestational age, adiposity or obesity, but that there may also be an influence of rapid weight gain in early childhood on pubertal onset: excess weight gain in childhood may be related to central adiposity, decreased insulin sensitivity, and increased IGF-I levels and might thus predispose to precocious pubarche.

Ontogeny of polycystic ovary syndrome and insulin resistance in utero and early childhood

Polycystic ovary syndrome (PCOS) is a prevalent hyperandrogenic infertility and cardiometabolic disorder that increases a woman's lifetime risk of type 2 diabetes mellitus. It is heritable and intensely familial. Progress toward a cure has been delayed by absence of an etiology. Evidence is mounting, however, for in utero T excess, together with gestational hyperglycemia, contributing to either early differentiation of PCOS or phenotypic amplification of its genotypes. Abnormal endocrine, ovarian, and hyperinsulinemic traits are detectable as early as 2 months of age in daughters of women with PCOS, with adiposity enhancement of hyperinsulinemia during childhood potentially contributing to hyperandrogenism and LH excess by adolescence. These findings encourage increasing clinical focus on early childhood markers for adiposity and hyperinsulinemia accompanying ovarian and adrenal endocrine abnormalities that precede a diagnosable PCOS phenotype. They raise the possibility for lifestyle or therapeutic intervention before and during pregnancy or during childhood and adolescence alleviating the manifestations of a familial genetic predisposition to PCOS.

[Follow-up of the small-for-gestational-age child: clinical guidelines]

INTRODUCTION

In this document the Small for Gestational Age (SGA) Child Working Group of the Spanish Society for Paediatric Endocrinology proposes the guidelines for the management and follow-up of SGA children, highlighting the potential morbidity arising from the SGA condition and its consequences in adulthood.

MATERIAL AND METHODS

There is currently a wide variability in the management of the SGA child between health centres and health professionals. The diagnostic criteria for SGA according to the last international consensus guidelines are defined, which also include preterm SGA patients but excluding those patients in whom low birthweigh is associated with specific syndromes. We also outline the potential abnormalities associated with the SGA condition and recommend specific therapeutic and preventative measures.

CONCLUSIONS

Low birth weight remains a major cause of morbidity in childhood and is associated with an increased risk of health problems later in life. Childhood is a critical window during which some of the risk factors accounting for this sequence are potentially reversible, with healthy lifestyle measures and environmental intervention. Accordingly, these guidelines should be useful not only for Primary Care Paediatricians but also for Neonatologists, Paediatric Endocrinologists, Neuropaediatricians and Pediatric Gastroenterologists, and also for the parents.

Ovarian reserve in young women with low birth weight and normal puberty: a pilot case-control study

AIM

Studies indicate that women born small for gestational age (SGA) have impaired ovarian function. The origin of this ovarian dysfunction is still debatable. The aim of this study was to compare ovarian ageing between girls born appropriate for gestational age (AGA) and SGA. Therefore, we measured Luteinizing hormone (LH), Follicle-stimulating hormone (FSH), E2, Anti-Müllerian hormone (AMH) levels and the pituitary response to endogenous Gonadotropin-releasing hormone (GnRH) in adolescent girls born SGA and AGA.

METHODS

A case-controlled pilot study consisting of seven SGA women (birth weight < 10th percentile AGA) and 13 AGA women with regular menstrual cycles, age 19.9 ± 0.42). Early follicular FSH, LH, Oestradiol (E2) and AMH levels were measured. After baseline samples, 100 μg GnRH was administered intravenously and at 30, 60 and 90 min blood samples were taken to measure gonadotropin levels and to compute the response to endogenous GnRH.

RESULTS

Mean follicular phase LH, FSH, E2 and AMH levels did not significantly differ between young women born SGA and AGA. Furthermore, the response to endogenous GnRH showed no significant differences either.

CONCLUSIONS

We concluded against extension of this pilot study. Based on our observations it seems unlikely that limited ovarian reserve is a predominated problem in adolescent SGA.

Latin American consensus: children born small for gestational age

BACKGROUND

Children born small for gestational age (SGA) experience higher rates of morbidity and mortality than those born appropriate for gestational age. In Latin America, identification and optimal management of children born SGA is a critical issue. Leading experts in pediatric endocrinology throughout Latin America established working groups in order to discuss key challenges regarding the evaluation and management of children born SGA and ultimately develop a consensus statement.

DISCUSSION

SGA is defined as a birth weight and/or birth length greater than 2 standard deviations (SD) below the population reference mean for gestational age. SGA refers to body size and implies length-weight reference data in a geographical population whose ethnicity is known and specific to this group. Ideally, each country/region within Latin America should establish its own standards and make relevant updates. SGA children should be evaluated with standardized measures by trained personnel every 3 months during year 1 and every 6 months during year 2. Those without catch-up growth within the first 6 months of life need further evaluation, as do children whose weight is ≤ -2 SD at age 2 years. Growth hormone treatment can begin in SGA children > 2 years with short stature (< -2.0 SD) and a growth velocity < 25th percentile for their age, and should continue until final height (a growth velocity below 2 cm/year or a bone age of > 14 years for girls and > 16 years for boys) is reached. Blood glucose, thyroid function, HbA1c, and insulin-like growth factor-1 (IGF-1) should be monitored once a year. Monitoring insulin changes from baseline and surrogates of insulin sensitivity is essential. Reduced fetal growth followed by excessive postnatal catch-up in height, and particularly in weight, should be closely monitored. In both sexes, gonadal function should be monitored especially during puberty.

SUMMARY

Children born SGA should be carefully followed by a multidisciplinary group that includes perinatologists, pediatricians, nutritionists, and pediatric endocrinologists since 10% to 15% will continue to have weight and height deficiency through development and may benefit from growth hormone treatment. Standards/guidelines should be developed on a country/region basis throughout Latin America.

Influence of preterm birth and small birth size on serum anti-Müllerian hormone levels in young adult women

BACKGROUND/OBJECTIVES

Preterm birth has been associated with reduced reproduction rates, and controversies remain regarding the effect of being born small for gestational age (SGA) on ovarian function. Recent findings in young men showed no effect of preterm and SGA birth on testis function. We hypothesised that follicle pool size in young adult women is also not affected by preterm and SGA birth.

DESIGN/METHODS

In 279 young women of the PROGRAM/PREMS study, aged 18-24 years, the influence of gestational age, birth length and birth weight on serum levels of anti-Müllerian hormone (AMH) was analysed with multiple regression modelling. Additionally, AMH levels were analysed in preterm- versus term-born females and in three subgroups: females born SGA with either short stature or catch-up growth (SGA-CU), and females born term and appropriate for gestational age with normal stature (AGA controls).

RESULTS

Preterm and SGA birth did not affect AMH and other hormone levels. Older age at menarche and oral contraceptive pill use (OC-use) were related to lower AMH levels, and maternal smoking during gestation was related to higher AMH levels. After correction for maternal smoking, lower socioeconomic status (SES) was associated with lower AMH levels. In subgroup comparisons, SGA-CU women showed higher AMH levels than AGA controls, also after adjustment for several factors.

CONCLUSION

Preterm and SGA birth did not affect AMH levels. Factors associated with serum AMH levels were OC-use, age at menarche, maternal smoking during gestation and SES. We conclude that preterm- and/or SGA-born females are not likely to have a reduced follicle pool size.

Growth-restricted preterm newborns are predisposed to functional adrenal hyperandrogenism in adult life

BACKGROUND

The long-term effects of perinatal growth and corticosteroid exposure on adrenal steroid concentrations in adults born very preterm are uncertain.

OBJECTIVES

To examine the effect of birth weight, early postnatal growth, and pre- and postnatal corticosteroid administration on serum adrenal steroids in 19-year-old subjects born very preterm.

DESIGN AND METHODS

Subjects born before 32 weeks of gestation in The Netherlands participating in the Project on Preterm and Small for Gestational Age Infants (POPS) were investigated at 19 years of age. Serum cortisol, DHEA sulfate (DHEAS), and androstenedione (Adione) concentrations were measured in 393 out of 676 eligible subjects, compared with controls, and associated with perinatal growth and pre- and postnatal corticosteroids administration using multiple linear regression analyses.

RESULTS

Serum DHEAS and Adione in men and women were higher than in controls. In the multiple regression analyses, birth weight SDS showed a statistically significant negative association with serum DHEAS concentrations in women (β: -0.865, 95% confidence interval (CI): -1.254 to -0.476) and in men (β: -0.758, 95% CI: -1.247 to -0.268) and with serum Adione concentrations in women (β: -0.337, 95% CI: -0.593 to -0.082). Early postnatal weight gain showed no association with any of measured adrenal markers. In women, serum Adione was associated with postnatal dexamethasone exposure (β: 0.932, 95% CI: 0.022 - 1.843).

CONCLUSIONS

Young adults born very preterm show elevated adrenal androgens, particularly when born small for gestational age. Postnatal corticosteroid administration is positively associated with serum Adione in young women.

Leuprolide acetate gonadotrophin response patterns during female puberty

OBJECTIVE

To assess normative data and the usefulness of spontaneous and LHRH analogue-stimulated serum LH and FSH levels measured by immunoradiometric assays (IRMA) in the evaluation of normal puberty.

DESIGN

Prospective. Healthy girls in Tanner I and Tanner II from the local community were invited to participate (n = 47).

METHODS

A leuprolide acetate test (500 mcg/m(2); sc) was performed. LH and FSH levels were determined using IRMA. Tanner II girls were assessed every 6 months until Tanner V. Girls who progressed from Tanner II to Tanner III in the next 6 months were called Tanner II-2; otherwise, they were called Tanner II-1.

RESULTS

The prepubertal upper limit (CI 95%) was 0.49 IU/l for basal LH and 5.1 IU/l for stimulated LH. Taking into account these LH cut-off limits, 72.2% and 66.7% of Tanner II-1 and 41.6% and 41.7% of Tanner II-2 subjects presented overlapping values for basal and stimulated LH, respectively, as compared with the Tanner I group. The cut-offs for basal and stimulated LH to predict progression from Tanner II to Tanner III in the next 6 months were a basal LH level > or =0.49 IU/l (Sensitivity = 0.58; 1-Specificity = 0.33) and a poststimulated LH level > or =4.75 IU/l (Sensitivity = 0.67; 1-Specificity = 0.44).

CONCLUSION

According to an IRMA, the basal and leuprolide acetate gonadotrophin response patterns during the beginning stages of puberty overlapped between Tanner I and Tanner II, and the cut-offs of basal and stimulated LH levels to predict progress from Tanner II to Tanner III had low sensitivities for the following 6 months.

Low-birth weight children develop lower sex hormone binding globulin and higher dehydroepiandrosterone sulfate levels and aggravate their visceral adiposity and hypoadiponectinemia between six and eight years of age

BACKGROUND

Most children born small for gestational age (SGA) normalize their body size by late infancy. Between 2 and 6 yr, such SGA children develop higher circulating levels of insulin, lower levels of adiponectin, and more visceral fat than appropriate-for-gestational-age (AGA) controls, even in the absence of overweight. Here we report on their further course between 6 and 8 yr. STUDY DESIGN AND POPULATION: Longitudinal study over 2 yr comparing data from 32 AGA vs. 32 SGA children, matched for gender, height, weight, and body mass index at the age of 6 yr.

MAIN OUTCOMES

Fasting insulin, dehydroepiandrosterone sulfate (DHEAS), SHBG, high-molecular-weight (HMW) adiponectin, leptin, IGF-I; body composition by absorptiometry; and abdominal fat partitioning by magnetic resonance imaging.

RESULTS

Between 6 and 8 yr, novel AGA-vs.-SGA divergences emerged (higher DHEAS and lower SHBG in SGA; P < 0.001), and some earlier divergences widened further (HMW adiponectin, visceral fat; P < 0.001), whereas others stabilized (fasting insulin, IGF-I). At age 8 yr, the most discerning features of SGA children were a high ratio of visceral over sc fat in the abdominal region (69% of SGA children), HMW hypoadiponectinemia (41%), fasting hyperinsulinemia (34%), and elevated circulating IGF-I levels (31%).

CONCLUSION

SGA children with spontaneous catch-up growth develop relatively high DHEAS and low SHBG levels and become more often HMW hypoadiponectinemic and viscerally adipose between 6 and 8 yr of age.

Impact of being born small for gestational age on onset and progression of puberty

Children born small for gestational age (SGA) are at higher risk for perinatal morbidity, mortality and chronic diseases in later life. There is increasing evidence for a link between prenatal growth and pubertal development, but studies concerning the timing, duration and progression of puberty in these children are scarce and the results are difficult to compare due to the various methodologies employed. Most boys born SGA have normal pubertal timing, but often attain an adult height below the target height. In girls, most studies document a relationship between intra-uterine growth retardation and earlier pubertal development or normal timing but with rapid progression. This chapter will discuss the factors that could influence pubertal development in children born SGA and the information reported to date.

Pubertal development in girls born small for gestational age

Puberty is one of the most important milestones in life. It not only represents the step into maturity, but also involves important body and physiological changes. There is increasing evidence for a link between prenatal growth and pubertal development, but the data concerning the timing, duration and progression of puberty in these children are scarce and the results are difficult to compare due to the various methodologies employed. In girls most studies document a relationship between intrauterine growth retardation and earlier pubertal development or normal timed puberty but with rapid progression. This review attempts to discuss the factors that could influence pubertal development in girls born small for gestational age and the information reported to date.

Ala54Thr polymorphism of the fatty acid-binding protein 2 gene (intestinal-type FABP) is associated with changes in insulin sensitivity in SGA pubertal girls

INTRODUCTION

Associations between FABP2 Ala54Thr polymorphism and increased fasting insulin concentration, fasting fatty acid oxidation and reduced glucose uptake have been identified in several populations. The aim of this study was to evaluate the association of Ala54 Thr polymorphism of the FABP2 gene with insulin sensitivity in pubertal girls born small for gestational age (SGA).

RESULTS

The frequency of the Thr54 allele did not differ between AGA and SGA girls (0.52 vs 0.43). Girls born SGA positive for the Ala/Thr polymorphism were older at the beginning of puberty compared to girls born AGA with the Thr54 allele (p < 0.01). These girls had lower whole body insulin sensitivity index (WBISI) (4.1 +/- 1.7 vs 9.2+/-7.4, p < 0.05), higher leptin (17.3 +/- 5.9 vs 12.1 +/- 13.7, p < 0.02), insulin area under the curve (AUC) (64,272 +/- 9,209 vs 27,981 +/- 15,637, p < 0.001), proinsulin (17.3 +/- 5.4 vs 10.9 +/- 3.6, p < 0.01) and insulinogenic index (4.6 +/- 3.0 vs 2.9 +/- 5.9, p < 0.01). Conversely, girls born SGA positive for the Ala/Thr polymorphism were older at the beginning of puberty (ns) compared to girls born SGA positive for the Ala/Ala polymorphism. These girls had higher insulin AUC (64,272 +/- 9,209 vs 33,322 +/-7,533, p < 0.01), insulinogenic index (4.6 +/- 3.0 vs 2.5 +/- 3.6, p < 0.01) and lower WBISI (4.1 +/- 1.7 vs 6.3 +/- 1.8, p < 0.05).

DISCUSSION

Our results suggest that the Thr54 variant of the FABP2 gene could be associated with a synergic effect in the SGA group regarding higher leptin levels (p < 0.05), lower insulin sensitivity by WBISI (p < 0.05) and higher insulin secretion determined by higher insulinogenic index (p < 0.01), insulin AUC (p < 0.01) and beta-cell stress measured by higher proinsulin (p < 0.05). Our data suggest an involvement of genetic factors in the insulin resistance associated with reduced fetal growth and strengthen the hypothesis that this association could be the consequence of interactions between detrimental factors during fetal life and genetic susceptibility.

Comparison of leptin levels, body composition and insulin sensitivity and secretion by OGTT in healthy, early pubertal girls born at either appropriate- or small-for-gestational age

BACKGROUND

Small for gestational age (SGA) has been associated with decreased insulin sensitivity (IS). A possible mechanism is the postnatal development of a metabolically disadvantageous body composition (BC).

AIM

To determine whether there are differences between IS and BC in girls in early puberty who were SGA (birth weight < 10th percentile) or appropriate for gestational age (AGA, 10th-90th percentile).

METHODS

Age-matched (SGA/AGA) early pubertal girls (Tanner II) were recruited from local schools. We determined waist circumference (WC), the sum of four skinfolds (S4S), and per cent fat mass (fat %) by impedanciometry. Leptin and OGTT assays were performed. The insulinogenic index (I-In), HOMA-IR (homeostasis model assessment of insulin resistance) and WBISI (whole body insulin sensitivity) were calculated.

RESULTS

Median age (interquartile range) for 30 SGA and 35 AGA girls was 10.2 (1.1) vs. 9.8 (0.9), respectively (P = NS). BMI percentiles were 62.6 (56) vs. 67.4 (39); WC 60.5 (9.5) vs. 62.2 (6.5) cm; S4S 52 (30) vs. 52.2 (29.5) cm, and fat %[26.2 (6.7) vs. 28.5 (6.3)] was similar in both groups. SGA girls had higher leptin levels [15.4 (9.7) vs. 9.6 (11) ng/ml; P = 0.01] and I-In [2.05 (1.86) vs. 1.47 (1.27) microU/ml* mg/dl; P = 0.02]. No differences between HOMA-IR [2.07 (1.26) vs. 2.04 (1.4)] and WBISI [5.3 (3.3) vs. 5.1 (3.1)] were found between groups.

CONCLUSION

The higher leptin level and I-In in girls born SGA at the beginning of puberty may be early indicators of an underlying subtle degree of insulin resistance, despite similar BMI and BC to AGA girls.

Small for gestational age: short stature and beyond

Depending on the definitions used, up to 10% of all live-born neonates are small for gestational age (SGA). Although the vast majority of these children show catch-up growth by 2 yr of age, one in 10 does not. It is increasingly recognized that those who are born SGA are at risk of developing metabolic disease later in life. Reduced fetal growth has been shown to be associated with an increased risk of insulin resistance, obesity, cardiovascular disease, and type 2 diabetes mellitus. The majority of pathology is seen in adults who show spontaneous catch-up growth as children. There is evidence to suggest that some of the metabolic consequences of intrauterine growth retardation in children born SGA can be mitigated by ensuring early appropriate catch-up growth, while avoiding excessive weight gain. Implicitly, this argument questions current infant formula feeding practices. The risk is less clear for individuals who do not show catch-up growth and who are treated with GH for short stature. Recent data, however, suggest that long-term treatment with GH does not increase the risk of type 2 diabetes mellitus and the metabolic syndrome in young adults born SGA.