Summer Birth Research Articles

Impact of the birth's season on the development of celiac disease in Italy.

our survey confirms that in Italy, children born in summer are at higher risk to develop CD than subjects born in other seasons. The identification of a responsible seasonal factor or factors, such as timing of the first introduction of gluten and/or acute viral gastrointestinal infections, would be very important for disease prevention strategies. • Environmental factors could be involved in the pathogenesis of CD. • Data about the impact of season of birth on CD development is so far derived from North American, Northern European and Israeli surveys. • This is the first study in Southern Europe to find a relationship between season of birth (summer) and development of CD. • Summer-born infants are introduced to complementary feeding (gluten) in winter, when the rotavirus infection is at its highest peak; this may be the link between season of birth and development of CD.

Perinatal risk factors for acute myeloid leukemia.

Infectious etiologies have been hypothesized for acute leukemias because of their high incidence in early childhood, but have seldom been examined for acute myeloid leukemia (AML). We conducted the first large cohort study to examine perinatal factors including season of birth, a proxy for perinatal infectious exposures, and risk of AML in childhood through young adulthood. A national cohort of 3,569,333 persons without Down syndrome who were born in Sweden in 1973-2008 were followed up for AML incidence through 2010 (maximum age 38 years). There were 315 AML cases in 69.7 million person-years of follow-up. We found a sinusoidal pattern in AML risk by season of birth (P < 0.001), with peak risk among persons born in winter. Relative to persons born in summer (June-August), incidence rate ratios for AML were 1.72 (95 % CI 1.25-2.38; P = 0.001) for winter (December-February), 1.37 (95 % CI 0.99-1.90; P = 0.06) for spring (March-May), and 1.27 (95 % CI 0.90-1.80; P = 0.17) for fall (September-November). Other risk factors for AML included high fetal growth, high gestational age at birth, and low maternal education level. These findings did not vary by sex or age at diagnosis. Sex, birth order, parental age, and parental country of birth were not associated with AML. In this large cohort study, birth in winter was associated with increased risk of AML in childhood through young adulthood, possibly related to immunologic effects of early infectious exposures compared with summer birth. These findings warrant further investigation of the role of seasonally varying perinatal exposures in the etiology of AML.

The relationship of deficit syndrome with clinical symptoms, summer births and heritabilityin patients with schizophrenia

The relationship of deficit syndrome with clinical symptoms, summer births and heritabilityin patients with schizophrenia

Are Negative Symptoms Dimensional or Categorical? Detection and Validation of Deficit Schizophrenia With Taxometric and Latent Variable Mixture Models.

Studies have supported the validity of the deficit form of schizophrenia (ie, people with primary and enduring negative symptoms). A test of whether that group is a true taxon-that is, a distinct, discontinuous group-has yet to be conducted and the underlying structure of negative symptoms as categorical or dimensional remains undetermined. The present study examined the latent structure of negative and deficit symptoms to determine if a nonarbitrary boundary distinguishes deficit from nondeficit forms of schizophrenia (ie, whether these symptoms reflect a continuous or categorical variable). Schedule for the Deficit Syndrome ratings of 789 individuals with a psychotic disorder were submitted to taxometric and latent variable mixture analyses to test categorical vs dimensional hypotheses of negative symptoms and deficit schizophrenia. Analytic models favored a taxonic structure of negative symptoms and the validity of the deficit/nondeficit classification scheme. Taxometric classification outperformed clinician-based deficit/nondeficit classification in its association with summer birth, male sex, premorbid adjustment, neurocognition, and psychosocial functioning. Within taxon and complement classes, severity scores remained significant predictors of premorbid adjustment, neurocognition, and psychosocial functioning. Thus, although a categorical approach is validated, a hybrid categorical-dimensional conceptualization of negative symptoms also has validity for the prediction of external variables.

Highlights of This Issue

Arsenic poses a significant human cancer risk and millions worldwide are exposed to naturally occurring arsenic in grains, vegetables, meats and fish, and through food processed with water containing arsenic. Oberoi and colleagues estimated the global burdens of bladder, lung, and skin cancers due to inorganic arsenic in food using World Health Organization estimates of food consumption and reported arsenic levels in different foods. Worldwide, thousands of additional cases of bladder, lung, and skin cancers are attributable to inorganic arsenic in food. These findings warrant policy changes to help reduce arsenic in food.Exposure to light-at-night has been shown to disrupt melatonin production, but this effect has only partly been confirmed in studies of night shift workers. Papantoniou and colleagues examined the variation of urinary 6-sulfatoxymelatonin levels in day or night shift workers while continuously monitoring light exposure. 6-sulfatoxymelatonin levels were lower in night compared to day workers and the lowest 6-sulfatoxymelatonin levels were observed in night workers. These findings may relate to future cancer risks in these worker populations.Infections in early childhood may protect against pediatric acute lymphoblastic leukemia (ALL). Marcotte and colleagues selected pediatric ALL cases from the California Cancer Registry and investigated markers of exposure to infections, including date of birth, and the timing of influenza and respiratory syncytial virus (RSV) seasons. The authors observed an increased risk of ALL for spring and summer births and for those first exposed to an influenza or RSV season at nine to twelve months compared to those exposed during the first three months of life. These results support the hypothesis that infections in early childhood decrease risk of ALL.Inflammation influences cancer development and progression and an elevated platelet/lymphocyte ratio (PLR) has been linked to poor prognosis in several malignancies. Templeton and colleagues conducted a systematic review to explore the association of blood PLR and overall survival from various solid tumors. A significant association between blood PLR and survival was observed for colorectal, hepatocellular, gastroesophageal, ovarian, and pancreatic carcinoma. PLR represents an inexpensive biomarker with prognostic value in solid tumors.

Exposure to infections and risk of leukemia in young children.

Epidemiologic studies indicate that infections in early childhood may protect against pediatric acute lymphoblastic leukemia (ALL). We identified 3,402 ALL cases among children 0 to 5 years of age using the California Cancer Registry. From California birth records we randomly selected controls in a 20:1 ratio and frequency matched them to cases by birth year. We investigated markers of exposure to infections, including month of birth, timing of birth in relation to influenza and respiratory syncytial virus (RSV) seasons, and birth order based on data from California birth certificates and national infection surveillance systems. We observed an increased risk of ALL for spring and summer births, and for those first exposed to an influenza or RSV season at nine to twelve months of age compared with those exposed during the first three months of life, and this association was stronger among first born children [odds ratios (OR), 1.44 and 95% confidence intervals (CI), 1.13-1.82, for influenza exposure at nine to twelve months of age]. Decreased risk was observed with increasing birth order among non-Hispanic whites but not Hispanics (OR, 0.76 and 95% CI, 0.59-096, for fourth or higher birth order among whites). Our results support the hypothesis that infections in early childhood decrease risk of ALL. Our findings implicate early life exposure to infections as protective factors for ALL in young children.

Season of birth and risk of Hodgkin and non‐Hodgkin lymphoma

Infectious etiologies have been hypothesized for Hodgkin and non-Hodgkin lymphoma (HL and NHL) in early life, but findings to date for specific lymphomas and periods of susceptibility are conflicting. We conducted the first national cohort study to examine whether season of birth, a proxy for infectious exposures in the first few months of life, is associated with HL or NHL in childhood through young adulthood. A total of 3,571,574 persons born in Sweden in 1973-2008 were followed up through 2009 to examine the association between season of birth and incidence of HL (943 cases) or NHL (936 cases). We found a sinusoidal pattern in NHL risk by season of birth (p = 0.04), with peak risk occurring among birthdates in April. Relative to persons born in fall (September-November), odds ratios for NHL by season of birth were 1.25 [95% confidence interval (CI), 1.04-1.50; p = 0.02] for spring (March-May), 1.22 (95% CI, 1.01-1.48; p = 0.04) for summer (June-August) and 1.11 (95% CI, 0.91-1.35; p = 0.29) for winter (December-February). These findings did not vary by sex, age at diagnosis or major subtypes. In contrast, there was no seasonal association between birthdate and risk of HL (p = 0.78). In this large cohort study, birth in spring or summer was associated with increased risk of NHL (but not HL) in childhood through young adulthood, possibly related to immunologic effects of delayed infectious exposures compared with fall or winter birth. These findings suggest that immunologic responses in early infancy may play an important role in the development of NHL.

Celebrating the Work of William T. Carpenter Jr

Celebrating the Work of William T. Carpenter Jr

First record of a neonate California sea lion (Zalophus californianus) in Manzanillo, Colima, Mexico

We present the first report of a neonate California sea lion near Manzanillo, Colima, Mexico, about 900km from the southernmost breeding colonies recognized for the species. The sighting occurred June 25th, 2011, and during the 2 following days, in La Boquita beach. Near the site of the sighting, sea surface temperature (SST) was recorded. SST values were some of the lowest recorded in the region (21−24°C), similar to the ones typically recorded in feeding areas in the southern Gulf of California in winter (∼20.9°C). California sea lion females give birth in summer and stay close to their colonies where they feed their young during approximately one year. Thus, their feeding areas tend to be confined within a radius of about 30km from their colonies. This close relationship between breeding and feeding make extralimital births important; the increasing knowledge regarding travel patterns of individuals may provide better ways to analyze the species status and its future conservation.

Season of birth in a nationwide cohort of coeliac disease patients

Background and objectiveGenetic factors alone cannot explain the risk of developing coeliac disease (CD). Children born in summer months are likely to be weaned and introduced to gluten during winter...

Season of birth effect on psychotic-like experiences in Japanese adolescents

A number of studies have investigated seasonality of birth in schizophrenia. Most of the studies have consistently observed an excess of winter births, often associated with decreased summer births. We postulated that psychotic-like experiences (PLEs), subclinical hallucinatory and delusional experiences, may also be affected by birth season. In the present study, we assessed the season of birth effect on the prevalence of PLEs using data from the cross-sectional survey of 19,436 Japanese adolescents. As a result, significant excess of winter births was observed in the prevalence of PLEs, accompanied by a decreased proportion of summer births. The odds ratios for the prevalence of PLEs were estimated to be 1.11, which was on the same order with those for the development of schizophrenia in the previous meta-analytic studies. To our knowledge, this is the first to show the seasonality of birth in the prevalence of PLEs and implicate the winter birth effect on subclinical stage of schizophrenia.Electronic supplementary materialThe online version of this article (doi:10.1007/s00787-012-0326-1) contains supplementary material, which is available to authorized users.

A Population-Based Case–Control Study of Extreme Summer Temperature and Birth Defects

Background: Although hyperthermia is a recognized animal teratogen and maternal fever has been associated with birth defects in humans, data on the relationship between high environmental temperatures and birth defects are limited.Objective: To determine whether pregnancies are potentially vulnerable to the weather extremes anticipated with climate change, we evaluated the relationship between extreme summer temperature and the occurrence of birth defects.Methods: We performed a population-based case–control study by linking the New York State Congenital Malformations Registry to birth certificates for the years 1992–2006. We selected nonmalformed infants from a 10% random sample of live births as controls. We assigned meteorologic data based on maternal residence at birth, summarized universal apparent temperature (UAT; degrees Fahrenheit) across the critical period of embryogenesis, and estimated adjusted odds ratios (aOR) and 95% confidence intervals (CI) with multivariable logistic regression, controlling for confounders available on the birth certificate.Results: Among 6,422 cases and 59,328 controls that shared at least 1 week of the critical period in summer, a 5-degree increase in mean daily minimum UAT was significantly associated with congenital cataracts (aOR = 1.51; 95% CI: 1.14, 1.99). Congenital cataracts were significantly associated with all ambient temperature indicators as well: heat wave, number of heat waves, and number of days above the 90th percentile. Inconsistent associations with a subset of temperature indicators were observed for renal agenesis/hypoplasia (positive) and anophthalmia/microphthalmia and gastroschisis (negative).Conclusions: We found positive and consistent associations between multiple heat indicators during the relevant developmental window and congenital cataracts which should be confirmed with other data sources.

Perinatal and Neonatal Risk Factors for Autism: A Comprehensive Meta-Analysis

Despite extensive epidemiologic research in the past several decades, the cause of autism is unknown. It is believed that the underlying etiology is polygenic, and that an interaction of environmental and genetic factors underlies the risk. Although several studies have reported that certain obstetrical and neonatal complications may be associated with increased risk of autism, the conclusions of these studies vary, in part, because of differences in methodology, diagnostic criteria, and comparison groups. The aim of this study was to provide the first systematic review and meta-analysis of the relationship between perinatal and neonatal factors and the risk of autism. A search of PubMed, Embase, and PsycInfo databases was conducted for epidemiologic articles published through March 2007 that examined the association between perinatal and neonatal factors and autism. A total of 40 studies met criteria for inclusion in the meta-analysis. A random-effects model was used to calculate a summary effect estimate for each exposure. For each of the several risk factors identified with heterogeneity in effect estimates across studies, meta-regression was used to identify measured methodological factors that could explain between-study variability. Over 60 perinatal and neonatal factors were examined in the 40 selected epidemiologic studies. There was an association between many of these factors and risk of autism. The strongest evidence was found for the following factors: abnormal fetal presentation, umbilical-cord complications, fetal distress, birth injury or trauma, multiple birth, maternal hemorrhage, summer birth, low birth weight, small for gestational age, congenital malformation, low 5-minute Apgar score, feeding difficulties, meconium aspiration, neonatal anemia, ABO or Rh incompatibility, and hyperbilirubinemia. Factors with the strongest evidence against a role in autism risk included anesthesia during delivery, assisted vaginal delivery, postterm birth, high birth weight, and head circumference. These findings provide insufficient evidence implicating any one perinatal or neonatal factor in autism etiology, but suggest combined risk from exposure to multiple perinatal and neonatal complications. Variability in methodology may account for the observed heterogeneity of risk factor effects across studies.

Perinatal and Neonatal Risk Factors for Autism: A Comprehensive Meta-analysis

The etiology of autism is unknown, although perinatal and neonatal exposures have been the focus of epidemiologic research for over 40 years. To provide the first review and meta-analysis of the association between perinatal and neonatal factors and autism risk. PubMed, Embase, and PsycInfo databases were searched for studies that examined the association between perinatal and neonatal factors and autism through March 2007. Forty studies were eligible for the meta-analysis. For each exposure, a summary effect estimate was calculated using a random-effects model. Heterogeneity in effect estimates across studies was examined, and, if found, a meta-regression was conducted to identify measured methodological factors that could explain between-study variability. Over 60 perinatal and neonatal factors were examined. Factors associated with autism risk in the meta-analysis were abnormal presentation, umbilical-cord complications, fetal distress, birth injury or trauma, multiple birth, maternal hemorrhage, summer birth, low birth weight, small for gestational age, congenital malformation, low 5-minute Apgar score, feeding difficulties, meconium aspiration, neonatal anemia, ABO or Rh incompatibility, and hyperbilirubinemia. Factors not associated with autism risk included anesthesia, assisted vaginal delivery, postterm birth, high birth weight, and head circumference. There is insufficient evidence to implicate any 1 perinatal or neonatal factor in autism etiology, although there is some evidence to suggest that exposure to a broad class of conditions reflecting general compromises to perinatal and neonatal health may increase the risk. Methodological variations were likely sources of heterogeneity of risk factor effects across studies.

Perinatal winter conditions affect later reproductive performance in romanian women: Intra and intergenerational effects

To compare epidemiological studies on Austrian and New Zealand women that report below average reproductive performance after birth in summer, with a similar study in Romanian women. We examined the association between birth month and offspring count analyzing census data from Romania obtained from IPUMS International (Population and Housing Census of Romania, year 2002), totaling 411,270 women aged older than 45 years. We investigated whether socio-economic status affected this association, and whether intergenerational effects exist for mother's birth month in relation to their daughter's offspring number. The time series of mean offspring count per birth month has a highly significant period of 12 months. Contrary to our expectations, average offspring count is highest in women born in June and lowest in those born in December, with a strong coincidence between negative peak values of residuals of mean offspring count per birth month and corresponding monthly means of ambient temperature in Romania. The association between winter birth and lower offspring number is significant in poorly educated women only. For mothers born in winter there is also an association with a lower daughters' offspring count. Conflicting results exist between Romania and Austria/New Zealand, and may be most easily explained by women's different exposure to winter conditions in these countries.

Illuminating the Profitability of Pairs Trading:A Test ofthe Relative Pricing Efficiency of Markets for WaterUtility Stocks

<h3>Background and objective</h3> Genetic factors alone cannot explain the risk of developing coeliac disease (CD). Children born in summer months are likely to be weaned and introduced to gluten during winter when viral infections are more frequent. Earlier studies on birth season and CD are limited in sample size and results are contradictory. <h3>Method</h3> Case–control study. We used biopsy reports from all 28 Swedish pathology departments to identify individuals with CD, defined as small intestinal villous atrophy (n=29 096). The government agency Statistics Sweden then identified 144 522 controls matched for gender, age, calendar year and county. Through conditional logistic regression we examined the association between summer birth (March–August) and later CD diagnosis (outcome measure). <h3>Results</h3> Some 54.10% of individuals with CD versus 52.75% of controls were born in the summer months. Summer birth was hence associated with a small increased risk of later CD (OR 1.06; 95% CI 1.03 to 1.08; p&lt;0.0001). Stratifying CD patients according to age at diagnosis, we found the highest OR in those diagnosed before age 2 years (OR 1.17; 95% CI 1.10 to 1.26), while summer birth was not associated with a CD diagnosis in later childhood (age 2–18 years: OR 1.02; 95% CI 0.97 to 1.08), but had a marginal effect on the risk of CD in adulthood (age ≥18 years: OR 1.04; 95% CI 1.01 to 1.07). <h3>Conclusions</h3> In this study, summer birth was associated with an increased risk of later CD, but the excess risk was small, and general infectious disease exposure early in life is unlikely to be a major cause of CD.

Formas deficitária e não deficitária da esquizofrenia não diferem quanto à sazonalidade de nascimentos nas regiões Sul e Sudeste do Brasil

Objetivos: Entre os pacientes com esquizofrenia originários do hemisfério norte, observa-se um excesso de 5%-10% de nascimentos no inverno e na primavera. Entretanto, entre os pacientes com a forma deficitária da doença, há uma pequena sobrerrepresentação de nascimentos no verão. Neste estudo, buscou-se verificar se tais associações se repetem entre os pacientes com esquizofrenia nascidos nas regiões Sudeste e Sul do Brasil. Métodos: Setenta e seis pacientes com esquizofrenia foram avaliados quanto a características sociodemográficas e psicopatológicas e categorizados quanto à presença da síndrome deficitária. Pacientes com e sem síndrome deficitária foram comparados quanto à estação de nascimento. Adicionalmente, compararam-se características psicopatológicas entre pacientes nascidos nas quatro estações do ano. Resultados: A distribuição de nascimentos de acordo com as estações não apresentou diferenças significativas. Entre pacientes com síndrome deficitária, dois terços nasceram no verão e outono, mas essa diferença não alcançou significância estatística. Não foram encontradas diferenças psicopatológicas relacionadas à estação do ano de nascimento. Conclusão: Nas regiões Sul e Sudeste do Brasil, não foi observado o excesso de nascimentos no verão entre pacientes ESquizofrênicos com síndrome deficitária, bem como não foi constatado excesso de nascimentos no inverno e primavera no grupo geral de pacientes com esquizofrenia.

Down-regulation of hepatic ApoB100 expression during hot season in transition dairy cows

Heat stress is recognized as one of the main factors adversely affecting yield, reproduction and health of dairy ruminants. The peripartum period is the most critical phase for dairy cows. The interaction between heat stress and physiological stress imposed by the peripartum, might worsen the metabolic status of transition dairy cows. Therefore, the objective of the present study was to investigate the effect of hot season on metabolic status and on hepatic apolipoprotein B100 (ApoB100) expression during the peripartum period in Holstein dairy cows. Twenty-four multiparous Holstein cows were utilized in the study. Twelve cows gave birth in spring (SP: 28 March to 30 April). The remaining 12 cows gave birth in summer (SU: 15 June to 2 July). The two groups were balanced for parity and body condition score (BCS) and monitored from −30 to 35d relative to calving. Values of air temperature (°C) and relative humidity (%) were recorded at 1h intervals and were utilized to calculate the temperature–humidity index (THI). Milk production and BCS were recorded weekly. Blood samples were taken at 0800h from the jugular vein −30, −18, and −4d prepartum and 3, 17, and 35d postpartum. Plasma was analyzed for glucose, urea, cholesterol, β-OH butyrate (BHBA), non-esterified fatty acids (NEFA) and ApoB100. Liver biopsies were performed on d −30, 3, and 35 relative to day of calving, and tissue samples were used for histopathological examination, and for ApoB100 mRNA and protein determination. Milk yield in SU cows was lower than in their SP counterparts. During summer, transition cows showed lower glucose and cholesterol, higher NEFA and BHBA, had lower liver ApoB100 gene and protein expression and higher lipid accumulation in liver compared with transition cows during spring. The current study provides the first evidence about the negative effects of hot season on ApoB100 gene and protein expression in transition dairy cows. The down-regulation of ApoB100 expression together with higher circulating NEFA and altered lipid metabolism are likely to be responsible for the higher risk of liver lipidosis in transition SU cows. These metabolic conditions make transition cows more susceptible to metabolic diseases during hot season.

Season of birth and risk of rotavirus diarrhoea in children aged &lt;5 years

This study investigates whether a child's risk of rotavirus diarrhoea is associated with season of birth in England and Wales, countries where rotavirus infections are highly seasonal. Poisson regression models were fitted to weekly counts of laboratory-confirmed rotavirus infections from children aged <5 years born between 1998 and 2007. In the first year of life, the risk of a laboratory-confirmed rotavirus infection was significantly higher for children born in summer compared with winter [relative risk (RR) 2.13, 95% confidence interval (CI) 2.07-2.19]. In the second to fifth years of life, the pattern reversed (second year of life: RR 0.73, 95% CI 0.71-0.75). The cumulative risk up to age 5 years remained significantly higher for children born in summer compared with winter due to the increased risk for summer births during their first year of life. Maternal immunity and age-specific levels of exposure to rotavirus could explain our findings.

Postpartum interval of Darfurian cows: Influences of breed, BCS, parity and season

The present study was designed to determine the length of postpartum interval (PPI) of some local Sudanese cows in South Darfur State namely Fellata, Kenana and cross bred cows (Kenana × Friesian). Furthermore the influence of body condition score (BCS) and parity on PPI was also investigated. In experiment 1 a total of 59 dairy cows that gave birth were employed to determine the length of PPI. The parity range of these cows was 1 to 5. Their BCS range was 2.5 to 4.The cows were grouped according to their breed into three groups. Group I was Kenana (n = 21), group II was Fellata (n = 17) and group III was cross-bred (n = 21).The PPI was recorded as the time elapse from parturition to the appearance of the first oestrous postpartum. The pure local cows of Fellata and Kenana had a significantly (p 0.05) in the PPI were found between Kenana and Fellata cows. Slight negative relation (R = 0.2) between BCS and the PPI was observed and parity did not influence PPI (R = 0.005), Experiment II was designed to study the influences of season on the PPI of the above mentioned cows. The PPI was compared among three groups of cows that gave birth in three different seasons. Group I was 18 cows that gave birth in summer (Kenana = 7, Fellata = 4 and cross-bred =7). Group II was 19 cows that gave birth in autumn (Kenana = 9, Fellata = 6 and cross-bred = 4) and group III was 31 cows gave birth in winter (Kenana = 13, Fellata = 11 and cross-bred = 7). The BCS and parity of these cows were similar to those of the above experiments. The results of this experiment showed that PPI of cross-bred cows was significantly ((p 0.05) in the PPI of cross-bred cows that gave birth in autumn and winter was found. Neither the PPI of Kenana nor that of Fellata cows were influenced by the season (P>0.05). It is concluded that the Kenana and Fellata cows have a similarly long PPI that would not be influenced by season whereas the cross-bred cows have a short PPI which is influenced by summer only. Additionally BCS has slight influence on the PPI while parity has no effect on it. Keywords: Cow, postpartum, breed, BCS, parity, season.