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Fieder M, Huber S. Detecting month and year of birth effects on reproduction and marriage patterns in two long-term data sets. Early Hum Dev 2024; 195:106073. [PMID: 39043080 DOI: 10.1016/j.earlhumdev.2024.106073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 07/03/2024] [Accepted: 07/03/2024] [Indexed: 07/25/2024]
Abstract
This study examines the effects of birth month on reproduction and mating behavior using historical and contemporary census data from 1820 to 1970. The research examines the effect of birth month on the number of children for women and their male spouses, finding a monthly cycle for both men and women. In addition, the study examines whether birth month influences whether a person has ever been married. In support of previous research, we find clear birth month effects on the number of children for both women and their spouses, while the time series of ever being married shows a 60-month and a 10-year cycle, the latter possibly related to the solar cycle. Although the effects are small, both results, based on a large and representative dataset, indicate the importance of early life factors on mating and reproduction.
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Affiliation(s)
- Martin Fieder
- Departement of Evolutionary Anthropology, University of Vienna, Djerassiplatz 1, 1030 Wien, Austria.
| | - Susanne Huber
- Departement of Evolutionary Anthropology, University of Vienna, Djerassiplatz 1, 1030 Wien, Austria
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2
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Begum MR, Ehsan M, Ehsan N. Impact of Environmental Pollution on Female Reproduction. FERTILITY & REPRODUCTION 2022. [DOI: 10.1142/s266131822230001x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The increased pollution in the world atmosphere is a global concern. Water, air, and soil are polluted by various sources, such as farm fertilizer, sewage industrial waste products, fumes, and plastics, which in turn impact human health. Plastics and other mixtures of waste affect live in the water. Moreover, the ecosystem is disrupted by the use of heavy metal-containing chemicals in agriculture, and those are eventually consumed by humans. The consequences are a significant negative impact on health including reproductive health, which impairs fertility in the human population. Reproductive functions are severely affected by different chemicals which may interfere with hormonal functions. Greater consequences are faced by the women as the number of germ cells present in the ovary is fixed during fetal life, and which are nonrenewable. From the production of ovum to fertilization, to implantation, and finally continuation of pregnancy, all are affected by the heavy metals and endocrine disruptors. Lifestyle modifications such as consumption of organic foods, plastic product avoidance, separation of residential areas from industrial/agricultural areas, proper waste disposal, and so on, may help to improve the situation.
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Affiliation(s)
| | - Mariya Ehsan
- Infertility Care and Research Center (ICRC), Dhaka, Bangladesh
| | - Nazia Ehsan
- Infertility Care and Research Center (ICRC), Dhaka, Bangladesh
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Pan D, Shao Y, Song Y, Huang D, Liu S, Zeng X, Liang J, Juan Jennifer Tan H, Qiu X. Association between maternal per- and polyfluoroalkyl substance exposure and newborn telomere length: Effect modification by birth seasons. ENVIRONMENT INTERNATIONAL 2022; 161:107125. [PMID: 35183942 DOI: 10.1016/j.envint.2022.107125] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 01/27/2022] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Telomere length (TL) is an important biomarker of biological aging and disease that may be affected by prenatal exposure to environmental pollutants. Birth seasons have been linked to reproductive and immune-related diseases. Prenatal exposure to per- and polyfluoroalkyl substance (PFAS) has been associated with adverse birth outcomes, but the effects of PFAS and birth seasons on newborn TL are poorly understood. OBJECTIVES To explore the individual and combined effects of maternal PFAS exposure on newborn TL, with exploration of the interaction between PFAS and birth seasons on newborn TL. METHODS Between June 2015 and May 2018, a total of 499 mother-newborn pairs were recruited for a birth cohort study in Guangxi, China. Maternal blood samples were collected during pregnancy. Nine PFASs were measured by ultraperformance liquid chromatography-mass spectrometry. Newborn TL was assessed using quantitative real-time polymerase chain reaction. Modeling newborn TL as the outcome, multivariable linear regressions were performed for individual PFAS exposures, and Bayesian Kernel Machine Regressions were performed for PFAS mixtures. Furthermore, interaction analyses were conducted to evaluate the effect modification by birth seasons in these relationships. RESULTS For both single and multipollutant models, PFASs exposure were inversely associated with newborn TL, although none of the relationships were significant. The mixture of PFASs showed a potential positive trend of combined effect on newborn TL but non-statistically significant. Each ln-transformed unit concentration increase in PFOA was related to a 20.41% (95% CI: -30.44%, -8.93%) shorter TL in spring-born infants but not in those born in other birth seasons. Mothers in the middle and highest tertiles of PFOA exposure had 11.69% and 10.71% shorter TLs in spring-born infants, respectively. CONCLUSION Maternal PFAS exposure showed little association with newborn TL. The results suggested potential effect modification by birth season on the association between PFOA exposure and newborn TL.
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Affiliation(s)
- Dongxiang Pan
- Department of Epidemiology and Health Statistics, School of Public Health, Guangxi Medical University, Nanning 530021, Guangxi, China
| | - Yantao Shao
- The Third Affiliated Hospital of Guangxi Medical University, Nanning 530031, Guangxi, China
| | - Yanye Song
- The Third Affiliated Hospital of Guangxi Medical University, Nanning 530031, Guangxi, China
| | - Dongping Huang
- Department of Sanitary Chemistry, School of Public Health, Guangxi Medical University, Nanning 530021, Guangxi, China
| | - Shun Liu
- Department of Child and Adolescent Health & Maternal and Child Health, School of Public Health, Guangxi Medical University, Nanning 530021, Guangxi, China
| | - Xiaoyun Zeng
- Department of Epidemiology and Health Statistics, School of Public Health, Guangxi Medical University, Nanning 530021, Guangxi, China
| | - Jun Liang
- Department of Epidemiology and Health Statistics, School of Public Health, Guangxi Medical University, Nanning 530021, Guangxi, China
| | - Hui Juan Jennifer Tan
- Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore
| | - Xiaoqiang Qiu
- Department of Epidemiology and Health Statistics, School of Public Health, Guangxi Medical University, Nanning 530021, Guangxi, China.
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Boland MR, Fieder M, John LH, Rijnbeek PR, Huber S. Female Reproductive Performance and Maternal Birth Month: A Comprehensive Meta-Analysis Exploring Multiple Seasonal Mechanisms. Sci Rep 2020; 10:555. [PMID: 31953469 PMCID: PMC6969210 DOI: 10.1038/s41598-019-57377-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 12/23/2019] [Indexed: 01/21/2023] Open
Abstract
Globally, maternal birth season affects fertility later in life. The purpose of this systematic literature review is to comprehensively investigate the birth season and female fertility relationship. Using PubMed, we identified a set of 282 relevant fertility/birth season papers published between 1972 and 2018. We screened all 282 studies and removed 131 non-mammalian species studies on fertility and 122 studies that were on non-human mammals. Our meta-analysis focused on the remaining 29 human studies, including twelve human datasets from around the world (USA, Europe, Asia). The main outcome was change in female fertility as observed by maternal birth month and whether this change was correlated with either temperature or rainfall. We found that temperature was either strongly correlated or anti-correlated in studies, indicating that another factor closely tied to temperature may be the culprit exposure. We found that rainfall only increases fertility in higher altitude locations (New Zealand, Romania, and Northern Vietnam). This suggests the possibility of a combined or multi-factorial mechanism underlying the female fertility - birth season relationship. We discuss other environmental and sociological factors on the birth season - female fertility relationship. Future research should focus on the role of birth season and female fertility adjusting for additional factors that modulate female fertility as discussed in this comprehensive review.
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Affiliation(s)
- Mary Regina Boland
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA.
- Institute for Biomedical Informatics, University of Pennsylvania, Philadelphia, USA.
- Center for Excellence in Environmental Toxicology, University of Pennsylvania, Philadelphia, USA.
- Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia, Philadelphia, USA.
| | - Martin Fieder
- Department of Evolutionary Anthropology, University Vienna, Vienna, Austria
| | - Luis H John
- Department of Medical Informatics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Peter R Rijnbeek
- Department of Medical Informatics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Susanne Huber
- Department of Evolutionary Anthropology, University Vienna, Vienna, Austria
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5
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Cho H. Ambient temperature, birth rate, and birth outcomes: evidence from South Korea. POPULATION AND ENVIRONMENT 2019; 41:330-346. [PMID: 32214579 PMCID: PMC7089350 DOI: 10.1007/s11111-019-00333-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The effects from rising temperatures, a symptom of climate change, have become a significant concern. This study finds that one additional day with a maximum temperature of 30-32 °C (86-89.6 °F), relative to a day with a temperature of 28-30 °C (82.4-86 °F), decreases the birth rate 9 months later by 0.24%, or 92 babies per month in South Korea. This result is robust to various specifications and samples. This study also found that the impact of the temperature bin did not vary according to the mother's characteristics, including education and age. That is, high temperature has no differential effect on mothers of different backgrounds. Finally, we found no significant temperature effect on birth outcomes, but we cannot rule out that children born 9 months after summer heat are a selected (healthy) group.
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Affiliation(s)
- Hyunkuk Cho
- School of Economics and Finance, Yeungnam University, 280 Daehak-ro, Gyeongsan, 712-749 South Korea
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6
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Boland MR. A model investigating environmental factors that play a role in female fecundity or birth rate. PLoS One 2018; 13:e0207932. [PMID: 30481214 PMCID: PMC6258536 DOI: 10.1371/journal.pone.0207932] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 11/08/2018] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE Over 12% of women in the United States have reduced fertility and/or fecundity. Environmental factors, such as temperature, and socioeconomic factors have been implicated in reducing female fecundity. The purpose of this study is to investigate the effect of environmental factors coupled with socioeconomic factors on birth rate at the country-level. We use birth rate as a proxy for female fecundity. This will enable us to identify the most important factors affecting female fecundity. METHODS Using country-specific data from 182 countries, we constructed a regression model of the effects of environmental and socioeconomic factors on birth rate at the country-level. Our model assesses the role of temperature, Gross Domestic Product (GDP) per capita, fine air particulate matter (PM 2.5), and prevalence of male and female Body Mass Index (BMI) > = 25 (age-standardized) on birth rate per country. Because many of these factors are inter-dependent, we include all possible two-way interaction terms to assess the role of individual factors and interactions between multiple factors in the model. RESULTS In the full regression model, we found that GDP per capita along with 5 interaction terms were significant after adjusting for multiple testing. Female BMI was only nominally significant. GDP per capita was independently associated with birth rate (adjusted p-value <0.001). Prevalence of BMI > = 25 age-standardized in males and females were also significant when interacting with air pollution or GDP on female fecundity (birth rate). Temperature did not affect birth rate either independently or as an interaction unless BMI was removed from the model. CONCLUSION A country's economic wealth was the most significant factor in predicting birth rate in a statistical model that includes environmental and socioeconomic variables. This is important for future studies investigating environmental factors involved in increasing or decreasing female fecundity.
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Affiliation(s)
- Mary Regina Boland
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
- Institute for Biomedical Informatics, University of Pennsylvania, Philadelphia, PA, United States of America
- Center for Excellence in Environmental Toxicology, University of Pennsylvania, Philadelphia, PA, United States of America
- Department of Biomedical and Health Informatics, Children’s Hospital of Philadelphia, Philadelphia, PA, United States of America
- * E-mail:
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Quesada JA, Nolasco A. Relationship between patients' month of birth and the prevalence of chronic diseases. Med Clin (Barc) 2017; 148:489-494. [PMID: 27993405 DOI: 10.1016/j.medcli.2016.10.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 10/17/2016] [Accepted: 10/20/2016] [Indexed: 01/05/2023]
Abstract
BACKGROUND AND OBJECTIVES Patients' month of birth can reflect exposure to certain factors during pregnancy and the first few months of life, which could influence the onset of chronic diseases during adulthood. The aim of this study is to evaluate the association between a patient's month of birth and the presence of chronic diseases in the Spanish population, by analysing the National Health Survey for the year 2006. PATIENTS AND METHODS We measured the association between 27 common chronic diseases and the month of birth, estimating the odds ratios and confidence intervals at 95%, using multivariate logistical models and adjusting the results for month of birth and potentially confounding variables. RESULTS The sample population was made up of a total of 29,478 individuals, representing approximately 44.7 million Spanish residents on 1 January 2007. Significant associations were found between the month of birth and several chronic diseases. There is a gender-differentiated risk pattern of developing chronic diseases according to the month of birth, with more significant associations and of greater magnitude being detected among men compared to women. CONCLUSIONS The associations detected might reflect early exposure to environmental factors in the uterus and during the first few months of life. More specific studies are required to gain a more in-depth understanding of these associations.
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Affiliation(s)
- Jose Antonio Quesada
- Departamento de Enfermería Comunitaria, Medicina Preventiva, Salud Pública e Historia de la Ciencia, Universidad de Alicante, Alicante, España.
| | - Andreu Nolasco
- Departamento de Enfermería Comunitaria, Medicina Preventiva, Salud Pública e Historia de la Ciencia, Universidad de Alicante, Alicante, España
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Reynolds JD, Case LK, Krementsov DN, Raza A, Bartiss R, Teuscher C. Modeling month-season of birth as a risk factor in mouse models of chronic disease: from multiple sclerosis to autoimmune encephalomyelitis. FASEB J 2017; 31:2709-2719. [PMID: 28292961 DOI: 10.1096/fj.201700062] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 02/21/2017] [Indexed: 12/13/2022]
Abstract
Month-season of birth (M-SOB) is a risk factor in multiple chronic diseases, including multiple sclerosis (MS), where the lowest and greatest risk of developing MS coincide with the lowest and highest birth rates, respectively. To determine whether M-SOB effects in such chronic diseases as MS can be experimentally modeled, we examined the effect of M-SOB on susceptibility of C57BL/6J mice to experimental autoimmune encephalomyelitis (EAE). As in MS, mice that were born during the M-SOB with the lowest birth rate were less susceptible to EAE than mice born during the M-SOB with the highest birth rate. We also show that the M-SOB effect on EAE susceptibility is associated with differential production of multiple cytokines/chemokines by neuroantigen-specific T cells that are known to play a role in EAE pathogenesis. Taken together, these results support the existence of an M-SOB effect that may reflect seasonally dependent developmental differences in adaptive immune responses to self-antigens independent of external stimuli, including exposure to sunlight and vitamin D. Moreover, our documentation of an M-SOB effect on EAE susceptibility in mice allows for modeling and detailed analysis of mechanisms that underlie the M-SOB effect in not only MS but in numerous other diseases in which M-SOB impacts susceptibility.-Reynolds, J. D., Case, L. K., Krementsov, D. N., Raza, A., Bartiss, R., Teuscher, C. Modeling month-season of birth as a risk factor in mouse models of chronic disease: from multiple sclerosis to autoimmune encephalomyelitis.
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Affiliation(s)
- Jacob D Reynolds
- Department of Medicine, University of Vermont, Burlington, Vermont, USA
| | - Laure K Case
- Department of Medicine, University of Vermont, Burlington, Vermont, USA
| | | | - Abbas Raza
- Department of Medicine, University of Vermont, Burlington, Vermont, USA
| | | | - Cory Teuscher
- Department of Medicine, University of Vermont, Burlington, Vermont, USA; .,Department of Pathology, University of Vermont, Burlington, Vermont, USA
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9
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Borsi JP. Hypothesis-Free Search for Connections between Birth Month and Disease Prevalence in Large, Geographically Varied Cohorts. AMIA ... ANNUAL SYMPOSIUM PROCEEDINGS. AMIA SYMPOSIUM 2017; 2016:319-325. [PMID: 28269826 PMCID: PMC5333224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We have sought to replicate and extend the Season-wide Association Study (SeaWAS) of Boland, et al.1 in identifying birth month-disease associations from electronic health records (EHRs). We used methodology similar to that implemented by Boland on three geographically distinct cohorts, for a total of 11.8 million individuals derived from multiple data sources. We were able to identify eleven out of sixteen literature-supported birth month associations as compared to seven of sixteen for SeaWAS. Of the nine novel cardiovascular birth month associations discovered by SeaWAS, we were able to replicate four. None of the novel non-cardiovascular associations discovered by SeaWAS emerged as significant relations in our study. We identified thirty birth month disease associations not previously reported; of those, only six associations were validated in more than one cohort. These results suggest that differences in cohort composition and location can cause consequential variation in results of hypothesis-free searches.
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Boland MR, Shahn Z, Madigan D, Hripcsak G, Tatonetti NP. Birth month affects lifetime disease risk: a phenome-wide method. J Am Med Inform Assoc 2015; 22:1042-53. [PMID: 26041386 PMCID: PMC4986668 DOI: 10.1093/jamia/ocv046] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 04/18/2015] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE An individual's birth month has a significant impact on the diseases they develop during their lifetime. Previous studies reveal relationships between birth month and several diseases including atherothrombosis, asthma, attention deficit hyperactivity disorder, and myopia, leaving most diseases completely unexplored. This retrospective population study systematically explores the relationship between seasonal affects at birth and lifetime disease risk for 1688 conditions. METHODS We developed a hypothesis-free method that minimizes publication and disease selection biases by systematically investigating disease-birth month patterns across all conditions. Our dataset includes 1 749 400 individuals with records at New York-Presbyterian/Columbia University Medical Center born between 1900 and 2000 inclusive. We modeled associations between birth month and 1688 diseases using logistic regression. Significance was tested using a chi-squared test with multiplicity correction. RESULTS We found 55 diseases that were significantly dependent on birth month. Of these 19 were previously reported in the literature (P < .001), 20 were for conditions with close relationships to those reported, and 16 were previously unreported. We found distinct incidence patterns across disease categories. CONCLUSIONS Lifetime disease risk is affected by birth month. Seasonally dependent early developmental mechanisms may play a role in increasing lifetime risk of disease.
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Affiliation(s)
- Mary Regina Boland
- Department of Biomedical Informatics Observational Health Data Sciences and Informatics (OHDSI)
| | | | - David Madigan
- Observational Health Data Sciences and Informatics (OHDSI) Department of Statistics
| | - George Hripcsak
- Department of Biomedical Informatics Observational Health Data Sciences and Informatics (OHDSI)
| | - Nicholas P Tatonetti
- Department of Biomedical Informatics Observational Health Data Sciences and Informatics (OHDSI) Department of Systems Biology Department of Medicine, Columbia University, New York, NY, USA
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Turnbull K, Nguyen LN, Jamieson MA, Palerme S. Seasonal trends in adolescent pregnancy conception rates. J Pediatr Adolesc Gynecol 2011; 24:291-3. [PMID: 21715196 DOI: 10.1016/j.jpag.2011.04.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 04/07/2011] [Accepted: 04/20/2011] [Indexed: 11/28/2022]
Abstract
STUDY OBJECTIVE The objectives of this study were to determine if a seasonal trend exists in adolescent pregnancies and to compare the teen conception rate per month to an adult population. SETTING The study was conducted in a tertiary care Canadian hospital that has a one-site model of care. DESIGN A retrospective chart review of all adolescent pregnancies over a 5-year period (N = 838) was undertaken. From the 13,554 adult pregnancies over the same time period, a random sample of 838 pregnancies was chosen for similar chart review. A chi-square test was used to compare the proportion of pregnancies conceived in each calendar month between the two groups. PARTICIPANTS Pregnancies ending in spontaneous abortions, elective terminations, ectopic pregnancies, as well as obstetrical deliveries, were included. RESULTS There was a significantly different monthly trend seen in adolescent pregnancy conceptions when compared with the adult group (χ² = 24.38, df = 11, P = 0.0112). The adolescent group was observed to have a unique peak in the number of pregnancies conceived in March (10.5% of pregnancies conceived compared to 7.3% in adults). In addition, 8.5% of conceptions in adolescents occurred in December compared to 10.4% in adults. CONCLUSIONS There are several plausible explanations for the modest but real differences identified in this study including trends in fecundity/fertility or social/school events that lead to increased sexual activity. Peaks in conception indicate times when a greater need for health care services exists, and when preventive education can be most effective.
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Affiliation(s)
- Kaitlyn Turnbull
- Department of Obstetrics and Gynecology, Queen's University, Kingston, Ontario, Canada.
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12
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Huber S, Fieder M. Perinatal winter conditions affect later reproductive performance in Romanian women: intra and intergenerational effects. Am J Hum Biol 2011; 23:546-52. [PMID: 21630366 DOI: 10.1002/ajhb.21184] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2010] [Revised: 02/15/2011] [Accepted: 03/20/2011] [Indexed: 01/31/2023] Open
Abstract
OBJECTIVES 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. METHODS 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. RESULTS 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. CONCLUSIONS 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.
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Affiliation(s)
- Susanne Huber
- Department of Anthropology, University of Vienna, Austria.
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13
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Sloboda DM, Hickey M, Hart R. Reproduction in females: the role of the early life environment. Hum Reprod Update 2010; 17:210-27. [DOI: 10.1093/humupd/dmq048] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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Döme P, Kapitány B, Ignits G, Rihmer Z. Season of birth is significantly associated with the risk of completed suicide. Biol Psychiatry 2010; 68:148-55. [PMID: 20416861 DOI: 10.1016/j.biopsych.2010.03.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 03/01/2010] [Accepted: 03/02/2010] [Indexed: 01/19/2023]
Abstract
BACKGROUND Previous studies have provided somewhat inconsistent results about the effects of season of birth on the risk of suicidal behavior. Therefore, we decided to investigate this question in a large sample of suicide completers. METHODS We determined the season of birth-associated risk of completed suicide between the years 1970 and 2008 among all individuals who were born in the area of today's Hungary between 1930 and 1939, 1941 and 1942, and 1944 and 1969. RESULTS The final sample of participants included around six and a half million people. About 80,000 completed suicides occurred among participants during the period investigated (the number of suicide completers in our study greatly exceeds the number of suicide completers in any previous studies). A significantly (p < .05) elevated risk of completed suicide was found among those individuals who were born in the high-risk period (spring and summer). Quantitatively, the biggest increase (7.6% [95% confidence interval: 5.4-9.9]) in suicide risk was detected among those who were born in July compared with the average risk of suicide in the population investigated. The associations between season of birth and the risk of completed suicide were stronger among male subjects than among female subjects and among those who committed suicide using violent methods than among those who chose nonviolent methods. CONCLUSIONS Our results from a large sample of suicide completers from Hungary--a country with one of the highest suicide rates in the world over the last century--strongly support the concept that the season of birth is significantly associated with the risk of completed suicide.
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Affiliation(s)
- Péter Döme
- Department of Clinical and Theoretical Mental Health, Kutvolgyi Clinical Center, Semmelweis University, Faculty of Medicine, Budapest, Hungary.
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15
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Cummings DR. Seasonal sunshine and vitamin D: a possible explanation for differences in European and United States birth patterns. BIODEMOGRAPHY AND SOCIAL BIOLOGY 2010; 56:105-122. [PMID: 21387984 DOI: 10.1080/19485565.2010.524093] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This study tests whether seasonal differences in the United States and European sunshine is associated with human birth patterns. Birth data are adjusted for 31-day months, leap years, and an annual percentage. Clear observations and birth indices are correlated for European and U.S. cities. With 2-month exposure to clearness, r-values are Chicago (0.63), Bismarck (0.81), Dallas (0.86), Thessaloniki (0.66), and Copenhagen (0.54) and, with 3-month exposure, Amsterdam (0.69). Peak clearness occurs during the autumn for the United States and spring/summer for Europe. Differences in clearness may explain birth pattern differences and reduced U.S. births in the 1930s. Although the effect of vitamin D is plausible, further research is required.
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Roux FE, Oucheng N, Lauwers-Cances V, Draper L, Cristini C, Collogly J, Lauwers F. Seasonal variations in frontoethmoidal meningoencephalocele births in Cambodia. J Neurosurg Pediatr 2009; 4:553-6. [PMID: 19951043 DOI: 10.3171/2009.7.peds08403] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Frontoethmoidal meningoencephalocele (fMEC) is relatively common in many Southeast Asian countries, with devastating aesthetic and social consequences for affected children. No cause has been detected to date. Among other factors, the authors of this paper attempt to identify a statistically significant difference in the spread of fMEC births throughout the year compared with other births. This seasonal variation in the incidence of fMEC births may provide clues to the causes of this condition. METHODS From a group of 175 children with fMEC who underwent surgery at the authors' humanitarian institution (Children's Surgical Centre) in Phnom Penh between 2004 and 2008, 86 children were studied. These children were born at full term and had an accurately recorded date of birth. The birth dates of this fMEC group were compared with a group of > 15,000 other live births at one of the main maternity units in Phnom Penh in 2005 and 2006. RESULTS Seasonal variation in incidence of fMEC by month of birth was highly statistically significant (p < 0.001), with the peak of births occurring in the dry season (between March and May). This is in contrast to the control group, in which there was an equal distribution of births throughout the year. More than 85% of the parents of children with fMEC who the authors treated were farmers, but this figure reflects the composition of the Cambodian population. CONCLUSIONS Uneven spread in the incidence of fMEC births throughout the year suggests that a seasonal factor during the wet season may be suspected in the pathogenesis of fMEC in Cambodia.
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Affiliation(s)
- Franck-Emmanuel Roux
- INSERM 825 et Service de Neurochirurgie, Hôpital Purpan, F-31059 Toulouse, France.
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