bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maternal Dietary Intake in Twin Pregnancies: Does it Diminish Towards Term?
Authors: Morley Ruth , Umstad Mark P. , Bond Jodie , Moore Vivienne M. , Owens Julie A. , Dwyer Terence , Carlin John B. 
Published: March 2007

AbstractWe tested the hypothesis that energy intake among women with twin pregnancies decreases in late gestation, as the uterus enlarges and they become increasingly uncomfortable. We asked women to recall dietary intake for the previous 24 hours, every 2 weeks from around 29 weeks of gestation, using a photographic atlas and other strategies to estimate portion size. Eighty women provided data at around 29, 31, 33 and 35 weeks of gestation. We calculated total energy intake, and energy intake from carbohydrate, fat and protein. Data were log transformed to reduce skewness. Using mixed effects linear regression models, we found minimal evidence that total energy intake changed over this time period, either before or after adjustment for potential confounding factors (95% confidence interval for relative change per week: −1.4%, 0.6%). There was weak evidence of a small decline in carbohydrate intake over time, both before and after controlling for energy intake. We cannot exclude change in energy intake or diet composition before 29 weeks or after 35 weeks of twin gestation.
Birthweight Discordance in Twins and the Risk of Being Heavier for Respiratory Distress Syndrome
Authors: Canpolat Fuat Emre , Yurdakök Murat , Korkmaz Ayse , Yigit Sule , Tekinalp Gülsevin 
Published: March 2007

AbstractTwin pregnancies are becoming common as a result of increased assisted reproduction. Studies have shown that the smaller twin of a pair is at greater risk of morbidity and mortality. Our aim was to determine if there is a relation between birth-weight discordancy and neonatal morbidity and mortality and to test the occurrence of respiratory distress syndrome (RDS) in discordant twins. For 5 years all twins admitted to our intensive care unit were included in the study. Discordance was calculated as the difference between twins' weights divided by the heavier weight. Diagnosis of RDS was made by typical clinical and radiographic methods. Multiple logistic regression was performed with gender, weight order and birth order as the independent variables and RDS as the dependent variable. Two hundred and sixty-six twin pairs with a mean gestation of 33 weeks and a mean birthweight of 1890 g were evaluated. Multiple logistic regression revealed that being the heavier twin was a more important risk factor for RDS (odds ratio 4.5; 95% confidence interval 2.2–9.2) than being the male or second-born twin. Based on neonatal outcomes a birthweight discordance equal or greater than 20% in twin pairs was accepted as the discordance criterion. Discordant and concordant groups were statistically different in neonatal mortality, necrotizing enterocolitis, polycytemia and hypoglycemia. Our data demonstrated that being the heavier twin is a risk factor for RDS and a birth-weight difference of 20% or more in twin pairs should be accepted as discordance.
Curves of Placental Weights of Live-Born Twins
Authors: Gielen Marij , Lindsey Patrick J. , Derom Catherine , Loos Ruth J. F. , Derom Robert , Nijhuis Jan G. , Vlietinck Robert 
Published: March 2007

AbstractThe purpose of this study is to present curves of estimated placental growth in twins and to evaluate the relative contribution of gestational age, zygosity, chorionicity, fusion of the placentas, sex of the individual and of the twin pair, site of the umbilical cord insertion, birth order, maternal age, and parity. Perinatal data and placental data were obtained from 6315 live-born twin pairs from the East Flanders Prospective Twin Survey. Of 4318 twin pairs, with no missing values, the placental weights of different gestational ages were analyzed using a nonlinear multivariate Gaussian regression. Two groups were distinguished: (1) twins with two separate placentas, and (2) twins with only one placental mass (one placenta in case of monochorionic twins or two fused placentas in case of dichorionic placentas). Overall, placental weight was influenced by gestational age, fusion of the placentas, and parity. In the case of one placental mass, monozygotic dichorionic twins had the lowest weights. If two separate placentas were present, birth order played a role in favor of the first-born twin. For parity and zygosity, the differences were most pronounced between 27 and 29 weeks, whereas the difference for birth order was most pronounced between 33 and 37 weeks. In conclusion, basic physiological characteristics, routinely examined at birth, influence placental weight. Taking these covariates into account allows a better evaluation of the placental weight given a gestational age, as an indicator of growth.
Twinning and Risk of Stillbirth Subtypes in Pediatric Mothers
Authors: Salihu Hamisu M. , Sharma Puza P. , Peters Shillena 
Published: March 2007

AbstractWe sought to estimate levels of risk for stillbirth subtypes associated with twin gestations among pediatric mothers (10–14 years). Analysis was on twin pregnancies covering the period 1989 to 2000 in the United States. We classified stillbirth as term, preterm, small-for-gestational-age (SGA) or preterm-SGA. We then assessed the risks of these stillbirth subtypes in pediatric mothers using two comparison groups consisting of women aged 15 to 19 years old (adolescent mothers) and 20 to 24 years old (mature mothers). Adjusted risk estimates were by means of hazard ratios generated from a Cox proportional hazards regression model. We adjusted for dependence of observations within twin clusters using the robust sandwich estimator. The rate of stillbirth was highest among pediatric mothers (56/1000), followed by adolescent gravidas (29/1000) and lowest in mature mothers (20/1000; p for trend < .01). Overall, preterm stillbirth was the most frequent stillbirth phenotype while term stillbirth was the least frequent. Not a single case of term stillbirth was recorded in pediatric mothers. Among pediatric gravidas, the risk for preterm stillbirth was more than tripled (adjusted hazard ratio [AHR] = 3.4; 95% confidence interval [CI] = 2.5–4.6), and that of preterm-SGA stillbirth more than doubled (AHR = 2.6; 95% CI = 1.8–3.7) that of mature mothers respectively. The 30% risk elevation for SGA stillbirth among pediatric mothers was not found to be statistically significant (AHR = 1.1; 95% CI = 0.3–4.3). Pediatric motherhood is a risk factor for stillbirth in twin gestation, especially, preterm and preterm-SGA stillbirth phenotypes. Prevention of stillbirth among this category of mothers should target the period preceding full term.
Outcome of Twins Delivery; Predictors for Successful Vaginal Delivery: A Single Center Experience
Authors: Salim Read , Lavee Michal , Nachum Zohar , Shalev Eliezer 
Published: March 2007

AbstractThe aim of this study was to compare maternal and neonatal outcome of twin births according to mode of delivery and to isolate the factors predicting a successful vaginal delivery and those predicting a failed trial of labor (TOL) leading to an emergent cesarean section. We reviewed all twin deliveries during the years 1995 to 2004. Parameters studied include maternal age, parity, gestational age, maternal antepartum complications and postpartum complications, fetal presentations, birthweight, mode of delivery of each twin, Apgar scores and cord pH. During the study period there were 40,710 deliveries of which 804 (1.9%) were twin deliveries. Of the 804 twins, 398 (49.5%) had planned cesarean sections (PCS) and 406 (50.5%) entered a TOL. Maternal age and parity were similar among the groups. Neonatal outcomes and postpartum complications did not differ between the groups. Of 406 women who had a TOL, 84.9% eventually delivered both twins vaginally. A significantly higher percentage of antepartum complications were noted among those who failed the TOL compared to those with successful TOL (8.2% vs. 1.7%,p=.01). The number of neonates with pH of less than 7.0 did not differ between the groups although more neonates (2.5% vs. 0.4%,p=.05) among the failed TOL had an Apgar score of less than 7.0 at 5 minutes compared to successful TOL. Vaginal delivery of both twins after TOL occurred in 91% of vertex/vertex compared with 71.8% of vertex/nonvertex presenting twins (p< .01). Neonatal outcomes did not differ between both groups. Our results indicate that both vaginal and PCS are comparable options for vertex presenting first twin regardless of second twin presentation.
Wisconsin Twin Panel: Current Directions and Findings
Authors: Lemery-Chalfant Kathryn , Goldsmith H. Hill , Schmidt Nichole L. , Arneson Carrie L. , Van Hulle Carol A. 
Published: March 2007

AbstractThe Wisconsin Twin Panel is based on the population of all twins born in the state of Wisconsin, United States. Our research focus is the etiology and developmental course of early emotions, temperament, childhood anxiety and impulsivity, the autism spectrum, auditory and tactile sensory sensitivity, and related psychobiological and behavioral phenotypes. We employ a range of research methods including structured interviews with caregivers, observer ratings, child self-report, home-based behavioral batteries, biological measures of basal and reactive cortisol, palm prints, birth records, genotyping, cognitive testing, and questionnaires. Reported results highlight the utility of employing multiple modes of assessment when studying child development and psychopathology.
Twin Towers: The Ones Left Behind; Research Reviews: Chimeric DZ Twins, DZ Twin Mothers; Revisited: The New York Child Development Center Twin Study; New and Unusual Twins
Authors: Segal Nancy L. 
Published: March 2007

AbstractTwin victims and survivors of the 2001 World Trade Tower attack are remembered. Central themes from the twin loss literature are also highlighted. Next, new research studies on dizygotic (DZ) twins and mothers of DZ twins are reviewed. Specifically, a rare monochorionic–diamniotic DZ twin pair with chimerism is described, and findings concerning genetic variants of GDF9 in mothers (that are associated with DZ twinning tendencies in families) are summarized. This is followed by another look at the controversial 1960s Child Development Center Twin Study that tracked the development of separated twins. Information on several new and unusual twins is also presented.
The Australian Twin ADHD Project: Current Status and Future Directions
Authors: Bennett Kellie S. , Hay David A. , Piek Jan , Pearsall-Jones Jillian , Levy Florence , Martin Neilson 
Published: March 2007

AbstractThis article describes the Australian Twin Attention-deficit/hyperactivity disorder (ADHD) Project (ATAP), the results of research conducted using this database and plans for future studies. Information has been actively collected from Australian families with twin children since 1991 for the ATAP database. The value of assessing siblings as well as twins is emphasized. Much work has gone into continuing the involvement of families in the study though this does become more difficult when twins reach maturity. The main focus of the project is ADHD in children and adolescents plus comorbid conditions including conduct disorder, oppositional defiant disorder, and generalized anxiety disorder. A major challenge has been how to retain continuity in the assessments, while at the same time covering changes in psychiatric classification, such as the move to Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 1994). Changes in the scale can affect the reports of twin similarity. Over the years, these twins have become part of other twin studies and future plans include linking different twin databases to investigate the relationships between childhood behavior and adult conditions. Recruitment, assessment and retention of twin families require a major commitment but create a significant resource for collaboration in areas outside the original aim.
Genetic and Environmental Influences on Dentofacial Structures and Oral Health: Studies of Australian Twins and Their Families
Authors: Townsend Grant , Richards Lindsay , Messer Louise Brearley , Hughes Toby , Pinkerton Sandra , Seow Kim , Gotjamanos Theo , Gully Neville , Bockmann Michelle 
Published: March 2007

AbstractOur studies of the teeth and faces of Australian twins commenced at the School of Dentistry, The University of Adelaide in the early 1980s. There are now over 900 pairs of twins enrolled in our continuing investigations, together with 1200 relatives. There are 3 main cohorts of participants. The first cohort comprises around 300 pairs of teenage twins for whom various records have been collected, including dental casts, facial photographs, finger and palm prints and information on laterality, including handedness. The second cohort comprises around 300 pairs of twins who have been examined at 3 stages of dental development from approximately 4 years of age to about 14 years: at primary, mixed, and permanent dentition (excluding 3rd molars) stages. The most recent study of tooth emergence and oral health, for which we are currently recruiting twins, will provide a third cohort of around 500 twin pairs aged from around birth to 3 to 4 years of age. Our broad aim in these studies has been to improve our understanding of how genetic and environmental factors contribute to variation in dental and facial features, and to oral health. We have also used our data to investigate aspects of the determination of laterality, particularly the fascinating phenomenon of mirror imaging. We plan to maximize the use of the longitudinal data and DNA we have collected, and continue to collect, by performing genome-wide scans for putative genetic linkage peaks for a range of dental features, and then to test for association between a series of likely candidate genes and our phenotypes.
The Qingdao Twin Registry: A Focus on Chronic Disease Research
Authors: Pang Zengchang , Ning Feng , Unger Jennifer , Johnson C. Anderson , Wang Shaojie , Guo Qian , Cao Weihua , Lee Liming 
Published: March 2007

AbstractWith the changing patterns of morbidity and mortality in China, noncommunicable chronic diseases have become the major threats to the health of the Chinese population. The causes of chronic diseases include genetic factors and behavioral risk factors such as the use of tobacco, alcohol, and other drugs, unhealthy dietary behaviors, and lack of physical activity. Twin studies offer a unique opportunity to disentangle the genetic and environmental risk and protective factors for chronic disease. The Qingdao Twin Registry (QTR) was initiated in 1998 as part of the National Chinese Twin Registry. Over 11,000 pairs of twins and multiples of all ages have been recruited into the registry. Several studies of physical and mental health are underway. Many of the adult twins have completed health and behavioral risk factor surveys, and the adolescent twins are participating in a study of gene–environment interactions in tobacco and alcohol use. Studies of the heritability of personality factors have been conducted. In 2002, Qingdao established the Qingdao Twin Health Promotion Association, a nonprofit organization that supports health services for twins and their parents, organizes special events and health-related activities for twins, and raises funds to conduct twin health examinations. The QTR will be a useful resource for future studies of population genetics in human health and disease.
The Danish Twin Registry in the New Millennium
Authors: Skytthe Axel , Kyvik Kirsten , Bathum Lise , Holm Niels , Vaupel James W. , Christensen Kaare 
Published: March 2007

AbstractThe Danish Twin Registry is the oldest national twin register in the world, initiated in 1954, and, by the end of 2005, contained more than 75,000 twin pairs born in the between 1870 and 2004. The Danish Twin Registry is used as a source for studies on the genetic influence on normal variation in clinical parameters associated with the metabolic syndrome and cardiovascular diseases, clinical studies of specific diseases, and aging and age-related health problems. The combination of survey data, clinical data and linkage to national health-related registers enables follow-up studies of both the general twin population and twins from clinical studies. This paper summarizes the newest extension of the register and gives examples of new developments and phenotypes studied.
Twin Studies in Finland 2006
Authors: Kaprio Jaakko 
Published: March 2007

AbstractIn studies on the Finnish Twin Cohorts, genetic and environmental determinants of common, complex diseases, and their behavioral risk factors have been investigated in Finland. In 1974, the older twins were identified, with a total of 13,888 like-sexed pairs of known zygosity. They have participated since 1975 in mail surveys, clinical examinations for subsamples, have been used to recruit families, and have been followed up for morbidity using national medical registers. Opposite twin pairs were added later. Two longitudinal studies of adolescent twins and their families, known as the FinnTwin12 and FinnTwin16 studies, have focused on determinants of health-related behaviors and disease in adolescents and young adults. This article describes current, ongoing data collection and analyses.
The Jena Twin Registry and the Jena Twin Study of Social Attitudes (JeTSSA)
Authors: Stößel Katharina , Kämpfe Nicole , Riemann Rainer 
Published: March 2007

AbstractThe Jena Twin Registry focuses on identifying twins in eastern Germany. It is based in part on registers of multiple births and data from registration offices, and in part on a volunteer sample approached by media calls and twin clubs. The Jena Twin Study of Social Attitudes (JeTSSA) is the first study based on the Jena Twin Registry. In a sample of 226 monozygotic and 168 dizygotic adult twin pairs, self- and independent reports of significant others (peers, spouses, parents) are collected to estimate genetic and environmental effects on social attitudes and the covariation of genetic influences on personality traits and social attitudes. In addition, the effects of measured environmental variables on attitude formation are examined.
The Longitudinal Israeli Study of Twins (LIST): Children's Social Development as Influenced by Genetics, Abilities, and Socialization
Authors: Knafo Ariel 
Published: March 2007

AbstractThe goals, prospects and methods of the Longitudinal Israeli Study of Twins (LIST) are described. This study is interested in children's prosocial development from phenotypic, genetic and environmental perspectives. It focuses on measuring prosociality with a multi-trait multi-method approach, and relating it to children's general cognitive and sociocognitive abilities, and to parenting in the family. Other variables of interest such as children's temperament and parental values are discussed, as are ideas for further research.
The Japanese Study of Adult Twins Reared Apart and Growing Old Separately
Authors: Hayakawa Kazuo , Kato Kenji , Onoi Miyuki , Hayashi Chisato , Yang-Ping Cai , Kanamori Masao , Doi Syuichi , Kikuchi Hiroyuki , Nishihara Reiko , Kadota Kensuke 
Published: March 2007

AbstractMore than 100 pairs of adult twins, reared apart and growing old separately, have participated in the Japanese Study of Adult Twins Reared Apart and Growing Old Separately since it began in 1974. The subjects are 161 pairs of adult twins born between 1910 and 1945 in Japan. The main focus of this study is to investigate the influences of environmental factors and life history on life satisfaction and psychological well-being in later adulthood. A mail survey has been conducted on these twins each year since 1974. To date, the Wechsler Adult Intelligent Scale, Maudsley Personality Inventory, Newgarten Life Satisfaction Index, comprehensive medical examinations and personal interviews have been conducted for 12 twin pairs residing in various areas of Japan.
Registry of Adolescent and Young Adult Twins in the Tokyo Area
Authors: Shikishima Chizuru , Ando Juko , Ono Yutaka , Toda Tatsushi , Yoshimura Kimio 
Published: March 2007

AbstractSince established in 1998, the Keio Twin Project (KTP) has been dedicated to investigating genetic and environmental sources contributing to human psychological traits in adolescence and young adulthood. A population-based twin registry was constructed by the KTP through the use of official residential records in the Tokyo area, and to date requests to participate in our research have generated 1040 pairs of twins and triplets of age 14 to 30, forming one of the largest twin registries in Asia. Our comprehensive datasets, obtained through questionnaires, performance tests, and physical measurements, cover a wide range of human traits: personality, psychiatry, mental health, sociality, cognition, and physical index. Demographic variables and environment of upbringing are also sought by twins and by some parents. This extensive information allows us to clarify the genetic and environmental overlap across multiple traits as well as specificities unique to single traits. Adding an evolutionary psychology perspective to the behavior genetics framework is currently being attempted in order to develop a grand theory of human genetics.
Netherlands Twin Register: From Twins to Twin Families
Authors: Boomsma Dorret I. , Geus Eco J. C. de , Vink Jacqueline M. , Stubbe Janine H. , Distel Marijn A. , Hottenga Jouke-Jan , Posthuma Danielle , Beijsterveldt Toos C. E. M. van , Hudziak James J. , Bartels Meike , Willemsen Gonneke 
Published: March 2007

AbstractIn the late 1980s The Netherlands Twin Register (NTR) was established by recruiting young twins and multiples at birth and by approaching adolescent and young adult twins through city councils. The Adult NTR (ANTR) includes twins, their parents, siblings, spouses and their adult offspring. The number of participants in the ANTR who take part in survey and / or laboratory studies is over 22,000 subjects. A special group of participants consists of sisters who are mothers of twins. In the Young NTR (YNTR), data on more than 50,000 young twins have been collected. Currently we are extending the YNTR by including siblings of twins. Participants in YNTR and ANTR have been phenotyped every 2 to 3 years in longitudinal survey studies, since 1986 and 1991 for the YNTR and ANTR, respectively. The resulting large population-based datasets are used for genetic epidemiological studies and also, for example, to advance phenotyping through the development of new syndrome scales based on existing items from other inventories. New research developments further include brain imaging studies in selected and unselected groups, clinical assessment of psychopathology through interviews, and cross-referencing the NTR database to other national databases. A large biobank enterprise is ongoing in the ANTR in which blood and urine samples are collected for genotyping, expression analysis, and meta-bolomics studies. In this paper we give an update on the YNTR and ANTR phenotyping and on the ongoing ANTR biobank studies.