Spring Births Research Articles

Environmental factors related to the induction of beta-cell autoantibodies in 1-yr-old healthy children

We studied environmental risk factors which might contribute to the development of beta-cell autoantibodies in healthy children. Here, we investigated 6000 randomly selected children from the large All Babies in Southeast Sweden (ABIS) cohort, including 17 055 newborns recruited between 1997 and 1999. Questionnaires at birth and at 1 yr of age and the levels of autoantibodies to glutamic acid decarboxylase (GADA) and autoantibodies to tyrosine phosphatase (IA-2A) at 1 yr of age were analyzed. The 99th percentile cutoff for autoantibodies was proposed to identify children at risk of type 1 diabetes (T1D) and the 90th percentile cutoff to identify children in whom beta-cell autoimmunity has been induced. Using the 90th percentile cutoff level, 1156 children had either IA-2A (n = 574) or GADA (n = 582), while 126 children had both GADA and IA-2A. When the 99th percentile cutoff level was used, 114 children had either IA-2A (n = 57) or GADA (n = 57), and six children had both GADA and IA-2A. In logistic regression analysis, celiac disease in grandparents [odds ratio (OR) 2.2] and maternal gastrointestinal infection (OR 1.1) represented a risk for simultaneous occurrence of both IA-2A and GADA above the 90th percentile. Birth in spring (March to May) (OR 1.5) and male gender (OR 1.3) were risk factors for induction of IA-2A. Mother's low education represented a risk for induction of IA-2A (OR 1.5) and GADA (OR 1.4). T1D in first-degree relatives increased the risk for beta-cell autoimmunity above the 99th percentile (OR 2.6), whereas type 2 diabetes in grandparents was associated with GADA (OR 2.1). Exposure to cow's milk formulas <2 months of age implied an OR of 2.9 for IA-2A above the 99th percentile.

The Influence of Extended Daylight on Outcomes of IVF/ICSI Cycles

The influence of seasonality and daylight length on mammalian reproduction has been well established. From analysis of historical birth records of countries at increased latitudes, prior to the widespread availability of family planning, there has existed a seasonal bias in human reproduction with an increase in conceptions occurring during the summer months leading to spring births. This process is known as photoperiodism and appears to be under the control of the hormone melatonin. In Assisted Reproduction cycles there is much greater uncertainty as to the effect of seasonality, with some suggestions that in countries of higher latitudes daylight length may influence outcomes. We wished to confirm if this seasonal variation exists, and to what effect daylight plays on outcomes in IVF/ICSI cycles. This was a retrospective analysis. This was a 4-year retrospective analysis of 3568 cycles of IVF/ICSI performed at a single tertiary University Assisted Conception Unit between December 1997 and Nov 2001. From these 2709 cycles were isolated that used a standard long protocol regimen for pituitary desensitisation and ovarian stimulation with Human menopausal gonadotrophin (HMG). Data was collected with regard to the demographics of the patients undergoing treatment as well as the outcomes including, quantity of gonadotrophin utilised, oocytes retrieved, fertilisation, implantation and clinical pregnancy rates. To remove bias from this retrospective study we identified 266 patients who had undergone two cycles of assisted conception cycles, one performed during the summer months (April- September) and one during winter months (October-March). These patients acted as their own controls between the two cycles and matched data was then compared. Analysis of these 532 cycles in 266 patients showed that in 131 patients the first cycle was performed during the summer and in 135 patients the first cycle was performed in winter. When the data from the matched cycles were analysed the significant improvements seen in outcomes from cycles performed during summer months was confirmed. Cycles undertaken during summer months showed significantly less gonadotrophin was required for each oocyte retrieved 734 iu v 849 iu (p=0.003), as well as a significant improvement in implantation rates per embryo transferred 8.86 v 4.46 (p=0.016) and clinical pregnancy rate 15.7% (42/266) v 7.5%(20/266) (p=0.002). Increasing daylight had no effect on fertilisation rates seen in IVF cycles 50.3% v 50.0%. The results of this study appear to demonstrate the benefit of increased daylight length on outcomes of IVF/ICSI cycles. It is known that the anatomical and molecular substrates and receptors of the system that encodes changes in photoperiodism are preserved in humans and that this system appears intact from the retina to the cortex, pineal gland and hypothalamus. In animal studies melatonin receptors have been found in many different anatomical sites, including the ovary. It would therefore seem probable that melatonin may have actions at multiple sites and on multiple levels of the reproductive tract, and may exert a more profound effect either alone or through hormone cascades on outcomes of assisted conception cycles than has been previously considered. Further research is required to confirm these findings and to identify the possible mechanism of action for the effect of extended daylight on reproduction.

Lymphocyte functions in dairy cows in hot environment

This study was carried out to ascertain the effects of intense high environmental temperatures (HET) on lymphocyte functions in periparturient dairy cows. The study was undertaken from the beginning of March through the end of July 2003 in a commercial dairy unit located approximately 40 km north of Rome. Thirty-four Holstein cows were utilised in the study. Twenty-two of these cows gave birth in spring (SP cows), from 28 March to 30 April. The remaining 12 cows gave birth in summer (SU cows), between 15 June and 2 July. The two groups of cows were balanced for parity and were fed the same rations. Blood samples were taken 4, 3, 2 and 1 week before calving, and 1, 2 and 4 weeks after calving, in order to evaluate peripheral blood mononuclear cell (PBMC) function in vitro, and to determine plasma cortisol concentrations. After isolation, the PBMC were stimulated with mitogens and their response in terms of DNA synthesis and IgM secretion was measured. During spring, either the day (9-20 h) or the night (21-8 h) temperature humidity index (THI) was below the upper critical THI (72) established for dairy cows. During summer, the mean daily THI values were 79.5+/-2.9 during the day and 70.1+/-4.7 during the night. Furthermore, during summer, three heat waves (a period of at least 3 consecutive days during which there were less than 10 recovery hours) occurred. Recovery hours were intended hours with a THI below 72. The first heat wave lasted 5 days, the second 6 days, and the third 15 days. Compared to the SP cows, over the entire periparturient period the extent of DNA synthesis and IgM secretion levels were lower (P ranging from <0.01 to 0.0001) and higher (P<0.01) respectively, in the SU cows. Before calving, the SU cows also presented higher (P<0.01) concentrations of plasma cortisol compared to the SP cows. This study indicates that the effects of HET on the immune response depend on the specific immune function under consideration, and that neuroendocrinal changes due to HET may play a role in the perturbation of immune functions.

Season of birth and fluctuating asymmetry.

Fluctuating asymmetry (FA) refers to random, small deviations from perfect bilateral symmetry in morphological traits. These minor deviations from the ideal phenotype reflect environmental and genetic perturbations experienced during ontogeny. FA has been associated with negative health outcomes and many developmental disorders in humans. The prevalence of developmental disorders and adult health vary according to the month of birth, suggesting that seasonal stressors may leave enduring signs in the adult body, marked by high FA. The current study examined the relationship between FA and birth season. Data were collected for 205 males and females (average age = 20.39 years) on FA of 10 bilateral traits (second, third, fourth, and fifth digit length, palm height, wrist diameter, elbow width, ear height, foot breadth, and ankle circumference). Additional relationships were also investigated among FA, testosterone (T), and birth order. Results indicate that ear FA was lower for fall births compared to winter births in males. In females, palm FA was lower for fall births compared to those of the spring. FA of the digits was positively associated with T in males. Average FA, excluding the digits, decreased as the number of maternal siblings increased for both sexes. T concentrations in males were positively associated with the number of younger brothers. Our results generally confirm previous research on seasonal variation in adult longevity and neurological and psychiatric disorders, suggesting that winter and spring births are at risk for asymmetric developmental trajectory.

The epidemiology of extrahepatic biliary atresia in New York State, 1983-98.

The aetiology of biliary atresia, the leading cause of neonatal extrahepatic jaundice and the main indication for liver transplantation in children, is unknown. Recent research has focused on an infectious aetiology and the development of viral models in animals. The few published epidemiological studies report conflicting results for seasonal, geographical, and racial variations in incidence. In this study, New York State (NYS) Congenital Malformations Registry data from 1983 to 1998 were compared with resident live birth certificate data. County of residence, birth date, gestational age, birthweight, gender, maternal race and maternal age were extracted from the birth certificate data. Isolated and sequence cases were combined for analysis. Observed and expected numbers of cases were calculated by NYS region. Overall, 369 biliary atresia cases were reported in the 16-year study period, a rate of 0.85 [95% CI 0.76, 0.93] per 10,000 live births. Of these, 249 isolated/sequence cases were ascertained, a rate of 0.57 [95% CI 0.50, 0.64] per 10,000 live births. The rate ratio of biliary atresia in New York City (NYC) compared with other NYS was 2.19 [95% CI 1.69, 2.84]. Seasonal patterns varied by region with spring births at highest risk in NYC and September to November births at highest risk in other NYS. The rate ratio in black vs. white mothers was 1.94 [95% CI 1.48, 2.54]. Birthweight and gestational age were associated with biliary atresia with preterm low-birthweight infants at highest risk [RR 3.24, 95% CI 2.20, 4.76]. The association of isolated/sequence biliary atresia with season, preterm birth, and low birthweight in our study supports an infectious disease hypothesis.

Season of birth effect in narcolepsy

The causes of narcolepsy are unknown.1 Genetic factors such as positivity for HLA DR2 or certain genotypes of tumor necrosis factor–alpha or the orexin gene only explain a fraction of the risk. A season of birth effect has been observed in numerous studies for schizophrenia and bipolar disorder with a 10% excess of birth in winter and spring.2 Among the underlying factors discussed are infectious agents as well as seasonal variations in nutrition, light effects, and toxins.2 Most recently, the vitamin D hypothesis has been revisited.3 The production of vitamin D is associated with exposure to sunlight and the active 1,25 dihydroxyvitamin D3 is a potent modulator of immune functions,4 a dysfunction of which is presumably important before the onset of narcolepsy.1 Recently, a non significantly deviated pattern of birth rates in American narcoleptic patients was reported, …

Markers of Oxidative Status in Plasma and Erythrocytes of Transition Dairy Cows During Hot Season

The study was carried out to assess whether hot seasons affect the oxidative status of transition dairy cows. Twenty Holstein cows were utilized. Eleven of those cows gave birth in spring; the remaining nine cows gave birth in summer. Oxidative status was evaluated from 21 d before to 35 d after calving, determining oxidative markers in plasma [glutathione peroxidase activity, thiol groups, reactive oxygen metabolites, and thiobarbituric acid reactive substances (TBARS)] and in erythrocytes [glutathione peroxidase activity (GSH-Px-E), intracellular thiols (SH), superoxide dismutase activity (SOD) and TBARS]. The season did not modify plasma oxidative markers. In contrast, cows exposed to moderate heat stress (39.5±0.2°C rectal temperatures) due to summer temperature-humidity index (73.2±2.5 mean daily THI), showed higher erythrocyte SOD, GSH-Px-E, SH, and TBARS compared with spring cows, indicating a condition of oxidative stress in summer transition dairy cows. Some changes (the increase of SOD, for example), represent compensatory changes the cow is undergoing in response to increased oxidative stress. Under the conditions compared, the effect of heat stress on oxidative status in transition dairy cows by use of plasma markers does not give enough information to reach definitive conclusions. Erythrocytes are an appropriate and sensitive model to study the oxidative status of transition dairy cows exposed to hot environments.

Long-term trends in sunshine duration and its association with schizophrenia birth rates and age at first registration — data from Australia and the Netherlands

Back ground. Based on the well-described excess of schizophrenia births in winter and spring, we hypothesised that individuals with schizophrenia (a) would be more likely to be born during periods of decreased perinatal sunshine, and (b) those born during periods of less sunshine would have an earlier age of first registration. Methods. We undertook an ecological analysis of long-term trends in perinatal sunshine duration and schizophrenia birth rates based on two mental health registers (Queensland, Australia n=6630; The Netherlands n=24,474). For each of the 480 months between 1931 and 1970, the agreement between slopes of the trends in psychosis and long-term sunshine duration series were assessed. Age at first registration was assessed by quartiles of long-term trends in perinatal sunshine duration. Males and females were assessed separately. Results. Both the Dutch and Australian data showed a statistically significant association between falling long-term trends in sunshine duration around the time of birth and rising schizophrenia birth rates for males only. In both the Dutch and Australian data there were significant associations between earlier age of first registration and reduced long-term trends in sunshine duration around the time of birth for both males and females. Conclusions. A measure of long-term trends in perinatal sunshine duration was associated with two epidemiological features of schizophrenia in two separate data sets. Exposures related to sunshine duration warrant further consideration in schizophrenia research.

Number of older siblings of individuals diagnosed with schizophrenia

One of the most consistent epidemiological findings in schizophrenia research is the small excess of late winter/early spring births. There is also evidence that schizophrenia is associated with urban birth and with later birth order. One interpretation of these three findings is that respiratory viral infections brought into the household by children in crowded areas could disrupt foetal brain development and predispose to schizophrenia in later life. To further explore this hypothesis, case register data were used to assess if schizophrenics with a greater number of older siblings are more likely to be born in urban areas and during late winter/early spring months. Data from the Dublin and Three County Case Register were compiled relating to 2969 patients with schizophrenia and 5904 patients with neurosis. We used logistic regression analysis to determine if the number of older siblings differentiated schizophrenia from neurosis after controlling for the effects of gender, urban/rural birth, season of birth and sibship size, and to examine whether any interactions existed. The number of older siblings did not predict a diagnosis of schizophrenia over neurosis. There was no interaction between number of older siblings and urban birth, between number of older siblings and spring birth, or between number of older siblings, season of birth and urban birth. These data do not support the hypothesis that schizophrenia, by comparison with neurosis, is associated with an increased number of older siblings or that there is an interaction between number of older siblings, urban birth or season of birth.

Season of Birth and Substance Abuse: Findings From a Large National Sample

Season of birth is a putative etiological factor for several psychiatric illnesses. An excess of late winter and early spring births has been demonstrated repeatedly for schizophrenia, which has usually been interpreted as the result of prenatal or infant exposure to seasonally mediated "harmful effects," such as infectious diseases. This study determined whether the seasonal birth rates of substance abusers differed from those of unaffected control groups. The 1992 National Longitudinal Alcohol Epidemiologic Survey, an interview-based study of 42,862 men and women, provided data to assess the association between quarter year of birth and lifetime diagnoses of substance abuse. Logistic regression revealed decreases in winter births in men with histories of alcohol dependence. The significant interaction of sex with season of birth reflected an excess of fall births among male but not female alcoholics. In contrast, there was no evidence of seasonality of birth among alcohol abusers. Men and women with histories of illicit drug use had excesses of fall birth. Birth rates of men with past or present alcohol dependence, and of men and women with histories of illicit drug use, implicated seasonal factors in the pathogenesis of substance abuse. The similar birth patterns of illicit drug users and male alcoholics suggest that they may share some common etiological factor, such as seasonal effects on environmental temperature, hormonal function, or susceptibility to viral infection during pregnancy or early infancy.

Threatened Fishes of the World: Carcharias taurus (Rafinesque, 1810) (Odontaspididae)

Threatened Fishes of the World: Carcharias taurus (Rafinesque, 1810) (Odontaspididae)

Epidemiological comparison of schizophrenia and bipolar disorder

Schizophrenia and bipolar disorder share many epidemiological features in common, but there are also differences. Both disorders share some risk factors, suggesting etiological antecedents that date to the perinatal period; these include excess of winter–spring births, abnormal dermatoglyphics, and probably an excess of perinatal complications. By contrast, an excess of urban births and an excess of minor physical anomalies are present in schizophrenia, but apparently not in bipolar disorder. Bipolar disorder also may be found in geographic, presumably genetic, isolates and in higher prevalence in higher socio-economic groups, which also differentiates it from schizophrenia. It is hypothesized that a subset of individuals with bipolar disorder constitutes a distinct disease entity, but that the majority share some common etiological antecedents with schizophrenia and may represent a disease continuum.

Season of birth and schizophrenia: a systematic review and meta-analysis of data from the Southern Hemisphere

Aims: Data from the Northern Hemisphere support an excess of winter–spring births of individuals who later develop schizophrenia when compared with the general population. The data from the Southern Hemisphere have been less consistent. This paper will present a systematic review and meta-analysis of relevant data from the Southern Hemisphere. Methods: To identify relevant studies we searched electronic databases, reviewed citations from target publications and wrote letters to published authors in the field. The counts for observed and expected births were assessed in four planned comparisons. In the absence of significant heterogeneity, the data were combined using Mantel–Haenzel odds ratio in a fixed effect model. Results: Twelve studies were identified. Published and unpublished data from eight of these were able to be included in the analyses. For the two seasonal comparisons ( n=20 017), small but non-significant excesses were found in the first comparison (winter versus other seasons; OR=1.04, 0.99–1.08) and for the second comparison (winter and spring versus other seasons; OR=1.03, 0.99–1.07). For the two quarterly comparisons ( n=14 799), there was a small but non-significant excess found in the third comparison (third quarter versus other quarters; OR=1.03, 0.98–1.09), and a small but non-significant deficit in the fourth comparison (third and fourth quarter versus other quarters OR=0.99, 0.95–1.04). Conclusions: Assuming that season of birth acts as a proxy marker for fluctuating non-genetic risk-modifying factors for schizophrenia, this review suggests that in the Southern Hemisphere these factors may be weaker, less prevalent, less regular, and/or may be modified by other confounding or modifying variables.

Birth seasonality in bipolar disorder, schizophrenia, schizoaffective disorder and stillbirths

Background: More than 40 studies have been done on seasonal birth patterns for schizophrenia, but only two small studies have been done for DSM-III-R bipolar disorder and none for schizoaffective disorder. Two studies have also reported a significant relationship between schizophrenia births and stillbirths. Methods: In the largest study to date, birth data from four states was obtained on 126 987 state psychiatric hospitals inpatients divided into ‘process’ schizophrenia (disorganized, catatonic, undifferentiated), paranoid schizophrenia, schizoaffective disorder, bipolar disorder and major depression. Time series analysis compared these births to all general births and to stillbirths. Results: ‘Process’ schizophrenia, paranoid schizophrenia, schizoaffective disorder and bipolar disorder all had statistically significant seasonal excess births from December through March ( p = 0.0000). The largest excess was 5.8% for bipolar disorder. Major depression had significant excess births from March through May. Time series analysis showed statistically significant coherences between major depression and bipolar disorder (0.995) and between schizoaffective disorder and both ‘process’ schizophrenia (0.977) and bipolar disorder (0.977). Unexpectedly, a significant coherence was also found between paranoid schizophrenia and bipolar disorder (0.972). Excess stillbirths were found for each month from January through June and a significant coherence was found between stillbirths and paranoid schizophrenia (0.998). Conclusions: This study demonstrates that DSM-III-R bipolar disorder and schizoaffective disorder both have an excess of winter births, similar to that found in schizophrenia. Time series analysis, however, suggests that the causes may not be identical. Major depression, by contrast, has an excess of spring births.

Relationship of birth season to clinical features, family history, and obstetric complications in schizophrenia

Birth in late winter and spring has been consistently shown to be a risk factor of schizophrenia. The relationship of late winter/spring birth to clinical characteristics and other putative risk factors, such as family history and obstetric complications, may provide clues to etiology. Data relating to season of birth, clinical features, family history, and obstetric complications were analyzed for 192 patients with schizophrenia as defined by Research Diagnostic Criteria (including schizoaffective disorder). There was no significant association of season of birth with any of the psychopathological dimensions nor was there a significant association with obstetric variables or family history. However, winter-born schizophrenic patients who had a negative family history were more likely to have a history of obstetric complications. These findings suggest that obstetric complications associated with schizophrenia are perhaps the result of some seasonal risk factors important in those without a family history of the disorder.

Spring and summer births and diabete

Spring and summer births and diabete

Testing the effect of season of birth on familial risk for schizophrenia and related disorders.

An excess of late winter and early spring births in schizophrenia has been repeatedly demonstrated. Previous evidence has suggested that the risk for schizophrenia may differ in relatives of schizophrenic probands born in this high risk period v. at other times of the year. In an epidemiologically based family study conducted in the west of Ireland, we examined the relationship between season of birth in schizophrenia and schizophrenia spectrum probands and the risk for schizophrenia and related disorders in first-degree relatives. Risk was assessed using the Cox proportional hazard method. We examined four birth seasons previously shown to significantly predict risk for schizophrenia. Neither the risk for schizophrenia nor that for schizophrenia spectrum disorders in relatives was significantly associated with season of birth in probands. Season of birth does not, in this sample, identify schizophrenic probands with particularly high or low familial vulnerability to illness.

Season of birth and obstetrical complications in schizophrenics

Many studies indicate that both obstetrical complications (OCs) and birth in winter or early spring are risk factors for schizophrenia, but few studies have examined how these risk factors covary in the same subjects. We assessed pre- and perinatal OCs, while blind to diagnosis, using medical data recorded at the time of subjects' births, in 29 probands with DSM-III schizophrenia or schizoaffective disorder and 39 of their unaffected adult sibs. Pre- and perinatal OCs were both significantly more common in probands than sibs. Schizophrenics not born during the winter or early spring had significantly more total and perinatal OCs than schizophrenics born in other months, but did not differ for prenatal OCs. Results indicate that OCs increase risk for schizophrenia, but also suggest the possibility that the impact of OCs on this risk may be affected by season of birth.

THE EFFECT OF GENETIC AND ENVIRONMENTAL FACTORS ON THE PREVALENCE OF ALLERGIC DISORDERS AT THE AGE OF TWO YEARS

Purpose of the Study. To prospectively determine the effect of genetic and environmental factors upon the prevalence of allergic disorders noted by age 2 years. Study Population. With a relatively captive United Kingdom island population, 1174 children born over a 1-year period were evaluated at the age of 2 years. Methods. Information on family history, any diagnosis made by physicians over the 2 years, parental smoking, and presence of pets were obtained. Umbilical cord blood was obtained in 1106 cases for total IgE determination. Birth weight was used to analyze low birth weight as a factor. Socioeconomic information was also determined. Findings. Of the 1174 children, 275 had an allergic disorder. Rhinitis occurred in 3%, food intolerance in 5%, eczema in 11%, and asthma in 11%. Positive prick skin tests were noted in 5%. Risk factors determined by multivariate regression analysis were: For asthma—positive family history, male sex, low birth weight, maternal smoking and spring birth time. For eczema—family history only. For rhinitis—lower socioeconomic group and autumn birth time. For positive skin tests—male sex and low birth rate. Cord IgE values did not predict allergic disease at age 2 years. Reviewer9s Comments. This study of an English community helps to clarify important factors in the environment. The increased prevalence of asthma (11%) over rhinitis (3%) and the risk factors of maternal smoking, low birth weight, male sex, and spring versus autumn birth time favoring asthma is of particular interest. It would be interesting to see if the population develops a decreasing prevalence of asthma at age 2 years if the population can reduce the use of tobacco through education and public health efforts.

Prenatal Factors in the Pathogenesis of Schizophrenia

The excess of winter-spring births among individuals suffering from schizophrenia provides strong evidence for the existence of some prenatally occurring factors in the pathogenesis of schizophrenia. Recent epidemiological findings suggest that maternal viral infections during the second trimester of pregnancy may play a crucial role in the aetiology of adult schizophrenia. A 'two-hit window' hypothesis of the mechanism of action of prenatal factors in the pathogenesis of schizophrenia suggests at least two time-specific prenatal aetiological events. The observed association between prenatal viral infection and increased incidence of adult schizophrenia need not be a direct cytotoxic result of the viral infection, but may be caused indirectly, for example from foetal minor cerebral haemorrhages produced by the anticoagulant effects of aspirin.