Monthly changes in the gain and loss of growth in weight of children living in Guatemala.

Monthly increments of weight growth for a sample of 246 Guatemala City private school children are analyzed for the presence of a seasonal pattern in rates of growth. Neither a seasonal pattern nor any other periodic rhythm is found. It is observed that a significantly greater number of children aged 5.0 to 6.9 years experience their minimum annual growth rate during the dry season, with up to 60% of them losing or not gaining weight in any one month. Patterns of diet, exercise and disease cannot explain this trend. A possible association between minimum weight growth and maximum growth in height is discussed.     

Growth of opossums (Trichosurus vulpecula) in the Orongorongo Valley,Wellington, New Zealand, 1953–61

The growth of pouch young and juvenile Trichosurus vulpecula to maturity is described, based on animals gin‐trapped in 800 ha of indigenous forest in the Orongorongo Valley, near Wellington. Commencing in March 1953 opossums were trapped continuously for 1 year, and then intermittently until 1961. Four ageing criteria were considered: ossification of limb epiphyses and development of cranial ridges were unreliable; tooth wear and closure of the spheno‐occipital skull sutures were more satisfactory, and were adopted. For the first 180 days the mean growth followed a rectilinear regression when size, expressed as cube root of weight, was plotted against age. Thereafter growth accelerated greatly, but steadied towards the end of the first year; its rate increased after several months, and ceased at 2 to 21/2 years. Though adult males (2.65 kg) and females (2.41 kg) differed significantly in weight, there was no detectable difference during the growth phase. Births occurred throughout the year, but were markedly seasonal, 86% occurring between mid March and the end of May. A secondary birth peak in spring, recorded in other areas, was barely apparent. Most young consequently grew fastest in their first spring and summer. The growth pattern appeared to be mainly dependent on age rather than season_^ since all young reared in captivity conformed, irrespective of the season of birth.     

Month-of-birth effect on further body size in a pig model

Previous studies unanimously confirmed the existence of a dependence of human body size on the month of birth. The cause of the phenomenon has not been identified yet, although some possible causes were proposed e.g. seasonal changes of climatic and nutritional conditions. This study explored the issue in an animal model of 20,513 pigs. We found that body weights of 6-month-old pigs were the highest for subjects born in February, but for 2-month-old pigs the peak fell in May. Any statistical correlation between the month of birth and later body weight may be induced by (1) a long-term effect of the month of birth on further growth potential (LTE), or by (2) a short-term effect of seasonal factors differentiating the growth rate (STE), so we developed a mathematical method to separate the effects. The analysis proved that (1) the observed correlations resulted only from the STE, with May-June being the months of the highest growth tempo, and that (2) there was no significant LTE. The short-term effect was responsible for differences between patterns of weight for 2- and 6-month-old animals by the month of birth: since a pig monthly gain of weight increases with age, it is favorable for it to be born in February to attain the greatest weight at the age of 6 months, whereas 2-month-old piglets are heaviest when born a month or two before the May/June optimum for growth. The lack of a long-term effect of the month of birth on pigs’ weight supports the hypothesis of the cultural character of factor(s) responsible for the relationship between the month of birth and later body size in humans.     

Intergenerational effects of maternal birth season on offspring size in rural Gambia

Environmental conditions experienced in early life can influence an individual's growth and long-term health, and potentially also that of their offspring. However, such developmental effects on intergenerational outcomes have rarely been studied. Here we investigate intergenerational effects of early environment in humans using survey- and clinic-based data from rural Gambia, a population experiencing substantial seasonal stress that influences foetal growth and has long-term effects on first-generation survival. Using Fourier regression to model seasonality, we test whether (i) parental birth season has intergenerational consequences for offspring in utero growth (1982 neonates, born 1976-2009) and (ii) whether such effects have been reduced by improvements to population health in recent decades. Contrary to our predictions, we show effects of maternal birth season on offspring birth weight and head circumference only in recent maternal cohorts born after 1975. Offspring birth weight varied according to maternal birth season from 2.85 to 3.03 kg among women born during 1975-1984 and from 2.84 to 3.41 kg among those born after 1984, but the seasonality effect reversed between these cohorts. These results were not mediated by differences in maternal age or parity. Equivalent patterns were observed for offspring head circumference (statistically significant) and length (not significant), but not for ponderal index. No relationships were found between paternal birth season and offspring neonatal anthropometrics. Our results indicate that even in rural populations living under conditions of relative affluence, brief variation in environmental conditions during maternal early life may exert long-term intergenerational effects on offspring.     

Stability of the Association between Birth Weight and Childhood Overweight during the Development of the Obesity Epidemic

Objective: To assess whether changes in the birth weight distribution or changes in the association of birth weight with the later risk of childhood overweight have contributed to the development of the obesity epidemic. Research Methods and Procedures: A Danish population‐based cohort study of 124,615 girls and 128,346 boys (ages 6 to 13 years), born between 1936 and 1983, were studied. Birth weight and annual measurements of height and weight were obtained from school health records. Overweight was defined by BMI in relation to internationally accepted criteria. The relative risk of being overweight by birth weight was calculated separately for each age, sex, and time period. Results: The birth weight distribution remained relatively stable over time. Compared with children with a birth weight of 3.0 to 3.5 kg, the risk of overweight increased consistently with each increase in birth weight category among girls and boys and at all ages between 6 and 13 years. Furthermore, the association between birth weight and increased risk of overweight in childhood remained stable across a 48‐year period. Discussion: The increase in the prevalence of overweight could not be explained by time trends in the distribution of birth weight or by changes in the association between birth weight and the later risk of overweight over time. This implies that, unless the prenatal environment influences the later risk of overweight without increasing birth weight, the environmental influences contributing to the obesity epidemic in children of school age operate in the early postnatal period.     

Analyses of factors influencing the birth weight and neonatal growth rate of Cheetah (Acinonyx jubatus) cubs

Birth weight and the neonatal growth rate are reliable indicators of neonatal survival prospects. Data on weight at birth and consecutive weights until 40 days of age were recorded for cheetah cubs in 16 litters. Growth was found to be linear during the first 40 days of life. Weight data were used to evaluate the influence of several factors on birth weight and neonatal growth. The factors used in these analyses were sex, litter identity, litter size, average litter size over the first 40 days, birth weight, parents, gestation length, parity of the dam, and inbreeding. For birth weight and neonatal growth, litter identity was the major explanatory factor (81.8 and 85.3%). For birth weight, a significant influence of gestation length was found (p < 0.05), whereas inbreeding coefficient tended to decrease the birth weight (p = 0.09). Together, gestation length and inbreeding coefficient account for 57.5% of the between‐litter variation for birth weight. Factors with significant influences on neonatal growth are gestation length and parity (p < 0.05). The average litter size over the first 40 days tended to influence neonatal growth (p = 0.07). These three variables together account for 99.9% of the between‐litter variation for neonatal growth during the first 40 days of life. A comparison of neonatal growth between mother‐raised and hand‐raised cubs revealed a lower growth rate in hand‐raised cubs (45 vs. 27 g/day). Zoo Biol 18:129–139, 1999. © 1999 Wiley‐Liss, Inc.     

Seasonal change in specific needle weight ofPinus thunbergii

To evaluate the reserve dynamics in pine needles, an index of specific needle weight (SNW; dry weight per unit length of needles) was provided. Developed needles ofPinus thunbergii did not show any additional elongation in their second year. Thus the seasonal change in SNW of developed needles was proved to indicate the dynamics of reserves in needles. SNW showed distinct seasonal change. It increased from autumn to carly spring, followed by a decrease by mid summer. This pattern of change was similar to the change in specific leaf weight (SLW) of evergreen broad leaves in temperate regions. It was concluded that the change in SNW indicated clearly the dynamics of reserves in needles, showing the accumulation in non-growth seasons and the consumption in subsequent growth seasons. The decrease in SNW during the growth season was 10–15% of the maximum found in early spring.     

Fetal Origins of Obesity

The worldwide epidemic of obesity continues unabated. Obesity is notoriously difficult to treat, and, thus, prevention is critical. A new paradigm for prevention, which evolved from the notion that environmental factors in utero may influence lifelong health, has emerged in recent years. A large number of epidemiological studies have demonstrated a direct relationship between birth weight and BMI attained in later life. Although the data are limited by lack of information on potential confounders, these associations seem robust. Possible mechanisms include lasting changes in proportions of fat and lean body mass, central nervous system appetite control, and pancreatic structure and function. Additionally, lower birth weight seems to be associated with later risk for central obesity, which also confers increased cardiovascular risk. This association may be mediated through changes in the hypothalamic pituitary axis, insulin secretion and sensing, and vascular responsiveness. The combination of lower birth weight and higher attained BMI is most strongly associated with later disease risk. We are faced with the seeming paradox of increased adiposity at both ends of the birth weight spectrum—higher BMI with higher birth weight and increased central obesity with lower birth weight. Future research on molecular genetics, intrauterine growth, growth trajectories after birth, and relationships of fat and lean mass will elucidate relationships between early life experiences and later body proportions. Prevention of obesity starting in childhood is critical and can have lifelong, perhaps multigenerational, impact.     

Prospective cohort study of factors influencing the relative weights of the placenta and the newborn infant.

OBJECTIVES: To determine the demographic, environmental, and medical factors that influence the relative weights of the newborn infant and the placenta and compare this ratio with other factors known to predispose to adult ill health. DESIGN: Prospective cohort study. SETTING: The tertiary referral centre for perinatal care in Perth, Western Australia. SUBJECTS: 2507 pregnant women who delivered a single live infant at term. MAIN OUTCOME MEASURES: Placental weight, birth weight, and the ratio of placental weight to birth weight. RESULTS: By multiple regression analysis the placental weight to birthweight ratio was significantly and positively associated with gestational age, female sex, Asian parentage, increasing maternal body mass index, increased maternal weight at booking, lower socioeconomic status, maternal anaemia, and increasing number of cigarettes smoked daily. There were no consistent relations between the placental weight to birthweight ratio and measures of newborn size. CONCLUSIONS: The ratio of placental weight to birth weight is not an accurate marker of fetal growth. In its role as a predictor of adult disease the ratio may be acting as a surrogate for other factors which are already known to influence health and may act before or after birth. Determining the role that relative growth rates of the fetus and placenta have in predisposing to adult disease requires prospective study to account for the many confounding variables which complicate this hypothesis.     

Maternal inflammation, growth retardation, and preterm birth: insights into adult cardiovascular disease

The "fetal origin of adult disease Hypothesis" originally described by Barker et al. identified the relationship between impaired in utero growth and adult cardiovascular disease risk and death. Since then, numerous clinical and experimental studies have confirmed that early developmental influences can lead to cardiovascular, pulmonary, metabolic, and psychological diseases during adulthood with and without alterations in birth weight. This so called "fetal programming" includes developmental disruption, immediate adaptation, or predictive adaptation and can lead to epigenetic changes affecting a specific organ or overall health. The intrauterine environment is dramatically impacted by the overall maternal health. Both premature birth or low birth weight can result from a variety of maternal conditions including undernutrition or dysnutrition, metabolic diseases, chronic maternal stresses induced by infections and inflammation, as well as hypercholesterolemia and smoking. Numerous animal studies have supported the importance of both maternal health and maternal environment on the long term outcomes of the offspring. With increasing rates of obesity and diabetes and survival of preterm infants born at early gestational ages, the need to elucidate mechanisms responsible for programming of adult cardiovascular disease is essential for the treatment of upcoming generations.     

Demographics of the European hare (Lepus europaeus) in the Mediterranean climate zone of Australia

Demographic parameters of the European hare (Lepus europaeus) in southern Australia were investigated by dissecting hares shot by hunters during each month of the year. Gender, body weight, age, sucking, lactation, weight of the abdominal alimentary canal, weight of the left peri-renal fat body, pregnancy status, presence and counts of placental scars, litter size, and stage of gestation were recorded. From those data, growth rates, age at weaning, age and weight at puberty, date of conception, projected birth date, recruitment, survivorship, and the relationships between lactation and fat stores and alimentary capacity were determined.Fecundity of the southern Australian hares followed the seasonal pattern reported for northern hemisphere populations. However, output was lower per female and particularly per older female. Females began breeding at an earlier age such that recruitment into the southern Australian population was more dependent on females in their first year of life than on older females. Growth rates were comparable with European rates. Although high chill factors were apparently associated with higher leveret mortality, there was paradoxically higher overall mortality during the spring-early summer period of higher plant growth than in the late summer–winter period of lower plant growth and more extreme weather conditions. Fat was accumulated during pregnancy and would act as a buffer against the possibility of inadequate food availability during lactation, but hares increased the capacity of the alimentary canal during lactation and presumably with it their ability to assimilate energy to meet the demands of lactation.     

Role of seasonal factors in pre- and postnatal ontogenesis for etiology of type 1 diabetes mellitus

Type 1 diabetes mellitus is a chronic disease characterized by autoimmune degradation of insulin-producing beta-cells. It was shown in a number of epidemiological studies of seasonality of birth in children with type 1 diabetes that the autoimmune process began during fetal and postnatal development. No such studies were carried out in the former Soviet Union countries. The aim of the present study is to compare the seasonal birth month pattern in patients with type 1 diabetes (10780 men and 9337 women) born in 1960-2002 to that in the total population of Ukraine (14 785601 men and 13 911370 women) born during the same period. Significant differences were found between these two populations: chi-squared = 103.97, p < 0.0001 and 135.17, p < 0.0001 in men and women, respectively. The results of cosinor analysis showed similar sinusoidal birth patterns of patients with type 1 diabetes in all sub-groups, irrespective of the age of clinical disease expression: 0-9, 10-19, or 20-29 years. In all cases, the highest and lowest predispositions to type 1 diabetes were inherent in the people born in spring and autumn, respectively. We propose that seasonal differences in the birth pattern in the two above populations could be due to long-term programming of glucose-insulin metabolism determined by the effect of certain seasonal factors during early ontogenesis.     

Common polymorphic variation in the genetically diverse African insulin gene and its association with size at birth

The insulin variable number of tandem repeats (INS VNTR) has been variably associated with size at birth in non-African populations. Small size at birth is a major determinant of neonatal mortality, so the INS VNTR may influence survival. We tested the hypothesis, therefore, that genetic variation around the INS VNTR in a rural Gambian population, who experience seasonal variation in nutrition and subsequently birth weight, may be associated with foetal and early growth. Six polymorphisms flanking the INS VNTR were genotyped in over 2,500 people. Significant associations were detected between the maternally inherited SNP 27 (rs689) allele and birth length [effect size 17.5 (5.2–29.8) mm; P = 0.004; n = 361]. Significant associations were also found between the maternally inherited African-specific SNP 28 (rs5506) allele and post-natal weight gain [effect size 0.19 (0.05–0.32) z score points/year; P = 0.005; n = 728). These results suggest that in the Gambian population studied there are associations between polymorphic variation in the genetically diverse INS gene and foetal and early growth characteristics, which contribute to overall polygenic associations with these traits.     

Analysis of population changes by measurement of body weight in the Koshima troop of Japanese monkeys

Measurements of the body weight of monkeys in the Japanese monkey troop on Koshima islet in southern Japan have been made since 1970. Population changes in the troop have been recorded since 1952. The population changes were further analyzed on the basis of the body weight changes of the troop members. The recent history of the Koshima troop can be divided into three periods differing according to conditions of artificial feeding: (1) a semi-wild period (SW Period, 1952–63); (2) an artificial feeding period (AF Period, 1964–71); (3) and a restricted artificial feeding period (Non-AF Period, 1972–77). The AF Period represented a period of population growth, whereas the Non-AF Period was a declining one when the population density of the troop was roughly ten times that of most wild troops. These population changes, i.e., changes in population parameters especially in the population declining phase, could be fairly well understood from the general features of the body weight changes of the troop members, the slow body weight growth, elevation of age at first birth, and small size of adult females. Reproduction and survival were affected by seasonal and yearly changes in body weight. The pattern of changes in body weight displayed seasonal peaks in the autumn and spring. Of these, the former suggests that fruit eating in the autumn is an important factor in the reproduction and growth of the monkeys.     

Longitudinal somatometrical study on the growth patterns of newborn Japanese monkeys

Growth of Japanese macaques during their first year was analyzed longitudinally, using body measurements. Measurements of 44 somatometrical characters were taken on seven animals. Work with the newborn data produced a formula which fits well. The formula is: y=a (x+b) ⁿ (y=size, x=age). At first, growth was analyzed, character by character, using birth sizes and incremental increases. The results show a major growth pattern for many characters: increments vary inversely with birth size. Application of the growth formula produced two further insights: (1) growth pattern is not so simple as imagined from the birth size-increment pattern; and (2) the characters which deviate from the birth size-increment pattern have large growth only at the earliest period (in few months), in spite of their small size. Sex differences were clear within the first year, especially for characters which differ greatly between adults.     

Characterization of seasonal reproduction patterns in female pichis Zaedyus pichiy (Xenarthra: Dasypodidae) estimated by fecal sex steroid metabolites and ovarian histology

Reproductive strategies vary considerably among species, but most studies have focused on a very limited number of mammalian species. Knowledge of the reproductive cycle and behavior is essential for developing and implementing in situ and ex situ conservation strategies for threatened and endangered species. This study aimed at characterizing the seasonal reproductive pattern of female pichis Zaedyus pichiy, a threatened small armadillo native to arid regions of Argentina and Chile, through direct observations, histological studies, and by measuring fecal immunoreactive estrogens, progestagens and glucocorticoids in 10 wild-born, captive pichis and in free-ranging individuals. Results suggest that pichis are seasonal breeders that give birth to one yearly litter of 1–2 offspring, which do not leave the burrow until they are weaned at approximately 37 days. Ovarian follicular growth seems to occur throughout the year. Fecal progestagen, estrogen and glucocorticoid concentrations were minimal during the first half of pregnancy, increased to peak concentrations of up to 3500, 200 and 200 ng/g dry feces, respectively, and decreased before parturition. Postpartum progestagen concentrations were greater in lactating females than females that aborted or did not raise their offspring (p < 0.0001), which is probably related to an elevated corticosteroid synthesis that contributes to maintain lactation, given that fecal glucocorticoid concentrations were of similar pattern. Observations of a second pregnancy after late abortion or death of the newborn litter and sustained follicular growth during pregnancy and lactation suggest that female pichis can become receptive briefly after having lost their litter. Fecal estrogen and progestagen concentrations of non-pregnant, non-lactating females did not have a well-defined hormonal cyclic pattern, and corpora lutea were only observed in pregnant females.     

Growth differences between children of highland and coastal Ecuador

This study examines patterns of growth in height and weight among children (<60 months) of highland and coastal agricultural communities of Ecuador. Highland children are significantly shorter, but not significantly lighter than their coastal peers. Linear growth rates (cm/6 months) are comparable between the two samples. Growth rates for body weight (kg/6 m) are similar in highland and coastal boys, whereas highland girls display larger weight gains than their coastal counterparts. In both regions, linear growth is compromised to a much greater extent than growth in body weight, and growth faltering for both height and weight is most pronounced between birth and 24 months of age. The similarity in growth rates between the highland and coastal samples suggests that high altitude hypoxia plays a relatively small role in shaping growth during the first five years after birth. Rather, it appears that most of the disparity in height between the two samples can be attributed to differences established by 6 months of age. The pattern of growth retardation seen in both regions during the first 24 postnatal months is similar to that observed among impoverished populations throughout the world and is likely associated with the influence of nutritional and disease stressors. After 2 years of age, little or no “catch up” growth is seen in height, whereas improvements in weight gain are more pronounced, especially among highland girls. Ongoing research is investigating the nutritional and socio-economic correlates of growth within each region. © Wiley-Liss, Inc.     

Factors affecting refuge from parasitoid attack in a cynipid wasp, Aphelonyx glanduliferae

We examined seasonal patterns of gall morphology, growth, and survivorship of the agamic generation of a cynipid wasp, Aphelonyx glanduliferae, and discussed its mortality factors, especially from the point of view of refuge from parasitoid attack. Although the initiation period varied greatly among individual galls, the larvae of A. glanduliferae grew rapidly and reached their maximum size within 3 weeks before pupating in late September to early October. This growth period corresponded to the period when the gall walls became thinner. Parasitoid attack, which was the principal factor in the mortality of A. glanduliferae in the tree crown, was concentrated around the pupation period of the cynipid. Gall walls were significantly thinner in galls attacked by parasitoids than in those still containing a living cynipid. Therefore, the period available to parasitoids seems to be limited by both gall wall thickness and cynipid size. Thus, the growth pattern of A. glanduliferae larvae can have significance in that it narrows the window of vulnerability to parasitoids to a particular period. Although delaying gall initiation will also shorten the exposure period to parasitoid attacks, it was likely to increase the risk of death from gall abortion caused by seasonal degradation in the quality of host plant tissues. Although many cynipids were killed by disease in the galls that fell to the ground, the falling of mature galls to the ground may be another way to a parasitoid-free space. It is thus suggested that a trade-off among life history traits against multiple factors operates in the refuge of A. glanduliferae from parasitoid attack. Received: May 15, 2001 / Accepted: February 1, 2002     

Epigenetic regulation of the placental HSD11B2 barrier and its role as a critical regulator of fetal development

“Fetal programming” is a term used to describe how early-life experience influences fetal development and later disease risk. In humans, prenatal stress-induced fetal programming is associated with increased risk of preterm birth, and a heightened risk of metabolic and neurological diseases later in life. A critical determinant of this is the regulation of fetal exposure to glucocorticoids by the placenta. Glucocorticoids are the mediators through which maternal stress influences fetal development. Excessive fetal glucocorticoid exposure during pregnancy results in low birth weight and abnormalities in a number of tissues. The amount of fetal exposure to maternal glucocorticoids depends on the expression of HSD11B2, an enzyme predominantly produced by the syncytiotrophoblast in the placenta. This protects the fetus by converting active glucocorticoids into inactive forms. In this review we examine recent findings regarding placental HSD11B2 that suggest that its epigenetic regulation may mechanistically link maternal stress and long-term health consequences in affected offspring.