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BJOG : An International Journal of... Apr 2021The perinatal mortality and morbidity among twins vary by chorionicity. Although it is considered that monochorionicity is associated with an increased risk of preterm...
BACKGROUND
The perinatal mortality and morbidity among twins vary by chorionicity. Although it is considered that monochorionicity is associated with an increased risk of preterm birth in twin pregnancies, no systematic review exists evaluating this association.
OBJECTIVES
This systematic review was undertaken to assess the association between preterm birth and chorionicity in twin pregnancies.
SEARCH STRATEGY
We searched the electronic databases from January 1990 to July 2019 without language restrictions.
SELECTION CRITERIA
All studies on twin pregnancies where chorionicity and preterm birth were evaluated were included.
DATA COLLECTION AND ANALYSIS
Findings are reported as odds ratios with 95% confidence intervals. The estimates are pooled using random-effects meta-analysis.
MAIN RESULTS
From 13 156 citations, we included 39 studies (29 864 pregnancies). Monochorionicity was significantly associated with increased risk of preterm birth at ≤28, ≤32, ≤34 and <37 weeks in women asymptomatic and symptomatic for preterm labour (odds ratio [OR] 2.14, 95% CI 1.52-3.02, I = 46%, OR 1.55, 95% CI 1.27-1.89 I = 68%, OR 1.47, 95% CI 1.27-1.69, I = 60%, OR 1.66, 95% CI 1.43-1.93, I = 65%, respectively). Among those asymptomatic for preterm labour, significantly increased odds of preterm birth were seen for monochorionicity at gestations ≤34 weeks (OR 1.85, 95% CI 1.42-2.40, I = 25%) and <37 weeks (OR 1.75, 95% CI 1.22-2.53, I = 61%). Sensitivity analysis showed significantly increased odds of spontaneous preterm birth at ≤34 and <37 weeks for monochorionicity (OR 1.25, 95% CI 1.01-1.55, I = 0% and OR 1.41, 95% CI 1.13-1.78, I = 0%).
CONCLUSIONS
Monochorionicity is significantly associated with preterm birth at all gestations.
TWEETABLE ABSTRACT
In twin pregnancies, monochorionicity is associated with an increased risk of preterm birth at all gestations.
Topics: Adult; Chorion; Female; Humans; Pregnancy; Pregnancy, Twin; Premature Birth; Risk Factors; Twins, Dizygotic; Twins, Monozygotic
PubMed: 32888235
DOI: 10.1111/1471-0528.16479 -
Pediatric Surgery International Aug 2017Hirschsprung's disease (HSCR) is known to occur in families. The reported overall incidence of familial cases is 7.6%, with a higher incidence of 15-21% in total colonic... (Meta-Analysis)
Meta-Analysis Review
AIM OF THE STUDY
Hirschsprung's disease (HSCR) is known to occur in families. The reported overall incidence of familial cases is 7.6%, with a higher incidence of 15-21% in total colonic aganglionosis and 50% in the rare total intestinal aganglionosis. HSCR is extremely rare in twins. The aim of this study was to systematically analyse the patterns of HSCR in twins published in the literature.
METHODS
Electronic databases Pubmed and Medline were screened for relevant articles using the keywords "Hirschsprung's disease", "aganglionosis", "twins", "monozygotic", and "dizygotic". Examining reference lists identified further relevant papers.
MAIN RESULTS
Twelve studies with a total of 18 twin pairs were included in this analysis. 67% twins were discordant. HSCR was found in 24 out of 36 twin subjects (67%), of which 83% affected were male. Rectosigmoid type was reported in 71% of patients, long-segment disease in 21, and 8% presented with a total aganglionosis. Three twin pairs had at least one family member affected with HSCR.
CONCLUSION
HSCR was found in two-thirds of twin subjects with a male predominance. Rectosigmoid aganglionosis was the most common variant. Disease discordance was identified, where environmental insults were postulated to be predisposing factors to disease expression. Future studies investigating the disease-associated mutations in the already identified HSCR genes should provide insights into the genetic basis of HSCR in twins.
Topics: Diseases in Twins; Female; Hirschsprung Disease; Humans; Incidence; Male; Twins
PubMed: 28601901
DOI: 10.1007/s00383-017-4110-7 -
PloS One 2011Acute rheumatic fever is considered to be a heritable condition, but the magnitude of the genetic effect is unknown. The objective of this study was to conduct a... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Acute rheumatic fever is considered to be a heritable condition, but the magnitude of the genetic effect is unknown. The objective of this study was to conduct a systematic review and meta-analysis of twin studies of concordance of acute rheumatic fever in order to derive quantitative estimates of the size of the genetic effect.
METHODS
We searched PubMed/MEDLINE, ISI Web of Science, EMBASE, and Google Scholar from their inception to 31 January 2011, and bibliographies of retrieved articles, for twin studies of the concordance for acute rheumatic fever or rheumatic heart disease in monozygotic versus dizygotic twins that used accepted diagnostic criteria for acute rheumatic fever and zygosity without age, gender or language restrictions. Twin similarity was measured by probandwise concordance rate and odds ratio (OR), and aggregate probandwise concordance risk was calculated by combining raw data from each study. ORs from separate studies were combined by random-effects meta-analysis to evaluate association between zygosity status and concordance. Heritability was estimated by fitting a variance components model to the data.
RESULTS
435 twin pairs from six independent studies met the inclusion criteria. The pooled probandwise concordance risk for acute rheumatic fever was 44% in monozygotic twins and 12% in dizygotic twins, and the association between zygosity and concordance was strong (OR 6.39; 95% confidence interval, 3.39 to 12.06; P<0.001), with no significant study heterogeneity (P = 0.768). The estimated heritability across all the studies was 60%.
CONCLUSIONS
Acute rheumatic fever is an autoimmune disorder with a high heritability. The discovery of all genetic susceptibility loci through whole genome scanning may provide a clinically useful genetic risk prediction tool for acute rheumatic fever and its sequel, rheumatic heart disease.
Topics: Genetic Predisposition to Disease; Humans; Rheumatic Fever; Twin Studies as Topic; Twins, Dizygotic; Twins, Monozygotic
PubMed: 21980428
DOI: 10.1371/journal.pone.0025326 -
BMC Pregnancy and Childbirth Jul 2022Monochorionic dizygotic twins are a rare condition, mostly related to assisted reproductive technology. This type of twinning is burdened by the same risk of pregnancy...
BACKGROUND
Monochorionic dizygotic twins are a rare condition, mostly related to assisted reproductive technology. This type of twinning is burdened by the same risk of pregnancy complications found in monochorionic monozygotic pregnancies.
CASE PRESENTATION
We report a case of spontaneous monochorionic dizygotic twins sharing situs inversus abdominalis and isolated levocardia, with only one twin affected by biliary atresia with splenic malformation syndrome. We also conducted a literature review of the 14 available documented monochorionic dizygotic twin gestations spontaneously conceived.
CONCLUSIONS
It is still unclear how this unusual type of twinning can occur in spontaneous conception. The evidence so far suggest the importance to timely diagnose the chorionicity, in order to adequately manage the typical complications associated with monochorionicity.
Topics: Chorion; Female; Humans; Pregnancy; Pregnancy Complications; Pregnancy, Twin; Reproductive Techniques, Assisted; Twins, Dizygotic; Twins, Monozygotic
PubMed: 35836143
DOI: 10.1186/s12884-022-04866-x -
Prenatal Diagnosis Apr 2008The aim of this study was to evaluate the effect of selective feticide (SF) compared to expectant management (EM) on perinatal outcome in dichorionic and monochorionic... (Review)
Review
The aim of this study was to evaluate the effect of selective feticide (SF) compared to expectant management (EM) on perinatal outcome in dichorionic and monochorionic twins discordant for anencephaly. For this purpose, we conducted a systematic review of literature and added ten unpublished cases. As a result, we found that in dichorionic twins, mean gestational age (GA) at birth in the SF group was 38.0 weeks versus 34.9 weeks (P = 0.0002). Mean birth weight was 2922 g in the SF group versus 2474 g (P = 0.03). In monochorionic twins, mean GA at birth was 35.2 weeks versus 32.7 weeks (P = 0.1). Mean birth weight was 2711 g versus 1667 g (P = 0.0001). We conclude that while SF does not reduce perinatal mortality, it does result in significantly longer gestations and higher birth weight, and appears to be the management of choice in dichorionic twins discordant for anencephaly. In monochorionic twins, SF also increases birth weight, but in view of the complexity of this group, no clear recommendations can be made.
Topics: Anencephaly; Diseases in Twins; Female; Humans; Pregnancy; Pregnancy Outcome; Pregnancy Reduction, Multifetal; Pregnancy, Multiple; Prenatal Care; Twins, Dizygotic; Twins, Monozygotic
PubMed: 18302309
DOI: 10.1002/pd.1967 -
JAMA Network Open Aug 2022Although infancy is the most rapid period of postnatal growth and development, factors associated with variation in infant traits are not well understood. (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Although infancy is the most rapid period of postnatal growth and development, factors associated with variation in infant traits are not well understood.
OBJECTIVE
To synthesize the large twin study literature partitioning phenotypic variance in psychological traits and developmental milestones in infancy into estimates of heritability and shared and nonshared environment.
DATA SOURCES
PubMed, PsycINFO, and references of included publications were searched up to February 11, 2021.
STUDY SELECTION
Peer-reviewed publications using the classical twin design to study psychological traits and developmental milestones from birth to 2 years old were included.
DATA EXTRACTION AND SYNTHESIS
Data were extracted in line with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and categorized using the International Classification of Functioning, Disability and Health: Children and Youth Version. Data were pooled in 3-level random effects models, incorporating within-cohort variance in outcome measurement and between-cohort variance. Data were analyzed from March 2021 through September 2021.
MAIN OUTCOMES AND MEASURES
The primary outcomes were monozygotic and dizygotic twin correlations. These were used to calculate genetic and shared and nonshared environment estimates.
RESULTS
Among 139 publications that were systematically retrieved, data were available on 79 044 twin pairs (31 053 monozygotic and 47 991 dizygotic pairs), 52 independent samples, and 21 countries. Meta-analyses were conducted on psychological traits and developmental milestones from 106 publications organized into 10 categories of functioning, disability, and health. Moderate to high genetic estimates for 8 categories were found, the highest of which was psychomotor functions (pooled h2, 0.59; 95% CI, 0.25-0.79; P < .001). Several categories of traits had substantial shared environment estimates, the highest being mental functions of language (pooled c2, 0.59; 95% CI, 0.24-0.86; P = .001). All examined categories of traits had moderate or high nonshared environment estimates, the highest of which were emotional functions (pooled e2, 0.42; 95% CI, 0.33-0.50; P < .001) and family relationships (pooled e2, 0.42; 95% CI, 0.30-0.55; P < .001).
CONCLUSIONS AND RELEVANCE
These findings may be an important source of information to guide future gene discovery research, public perspectives on nature and nurture, and clinical insights into the degree to which family history and environments may estimate major domains of infant functioning, disability, and health in psychological traits and developmental milestones.
Topics: Adolescent; Child; Cohort Studies; Forecasting; Humans; Infant; Phenotype; Twins, Dizygotic
PubMed: 35994288
DOI: 10.1001/jamanetworkopen.2022.27887 -
Journal of Perinatal Medicine Sep 2020Objectives To compare the fetal and maternal outcomes in surviving singletons of vanishing twin, with singletons or twins, in pregnancies following assisted reproductive... (Meta-Analysis)
Meta-Analysis
Objectives To compare the fetal and maternal outcomes in surviving singletons of vanishing twin, with singletons or twins, in pregnancies following assisted reproductive technology (ART). Content We searched the PubMed, Embase, Web of Science and Cochrane databases from the time of conception of the database until Dec 2019 to identify relevant published studies. Perinatal outcomes were synthesized with random effects meta-analysis using RevMan 5.3. Summary and Outlook Fifteen studies were included. Dichorionic twin pregnancies conceived by ART wherein the vanishing twin phenomenon occurred had a risk of fetal malformation similar to that of ART singleton pregnancies (OR=1.25; 95% CI 0.87-1.79) and a higher risk of fetal malformation compared with ART twin pregnancies (OR=1.82; 95% CI 1.23-2.70). Moreover, the remaining fetus in ART vanishing twin pregnancy was at a significantly higher risk of preterm birth (<37 weeks) compared to fetuses in ART singleton pregnancies (OR=2.41; 95% CI 1.46-3.99) and a markedly lower risk of preterm birth (<37 weeks) compared to the fetuses in ART twin pregnancies (OR=0.19; 95% CI 0.16-0.22). Meanwhile, the risk of delivery of infants who were small for gestational age (SGA) was significantly higher in ART vanishing twin pregnancies compared to that in ART singleton pregnancies (OR=2.70; 95% CI 1.39-5.24) and similar to that in ART twin pregnancies (OR=0.67; 95% CI 0.27-1.65). The risks of preterm birth and of the infant being SGA is higher for the remaining fetus in an ART vanishing twin pregnancy compared to those for the fetuses in ART singleton pregnancies; the risk of fetal malformation is also higher in such cases compared with ART twin pregnancies.
Topics: Congenital Abnormalities; Female; Fetal Death; Humans; Infant, Newborn; Infant, Small for Gestational Age; Pregnancy; Pregnancy, Twin; Premature Birth; Reproductive Techniques, Assisted; Risk Assessment; Twins, Dizygotic
PubMed: 32697761
DOI: 10.1515/jpm-2020-0088 -
Wiener Klinische Wochenschrift 2007Convergent evidence from a multitude of research designs (adoption, family, genomescan, geographical, immigrant, molecular genetic, surname, and twin studies of suicide)... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
Convergent evidence from a multitude of research designs (adoption, family, genomescan, geographical, immigrant, molecular genetic, surname, and twin studies of suicide) suggests genetic contributions to suicide risk. The present account provides a comprehensive and up-to-date review of the twin studies on this topic.
METHODS
A total of 32 studies (19 case reports, 5 twin register-based studies, 4 population-based epidemiological studies, 4 studies of surviving co-twins) located through extensive literature search strategies are summarized and discussed here. This literature corpus was published between 1812 and 2006 in six languages and reports data from 13 countries.
RESULTS
A meta-analysis of all register-based studies and all case reports aggregated shows that concordance for completed suicide is significantly more frequent among monozygotic than dizygotic twin pairs. The results of co-twin studies rule out exclusively psychosocially based explanations of this pattern. Population-based epidemiological studies demonstrate a significant contribution of additive genetic factors (heritability estimates: 30-55%) to the broader phenotype of suicidal behavior (suicide thoughts, plans and attempts) that largely overlaps for different types of suicidal behavior and is largely independent of the inheritance of psychiatric disorders. Nonshared environmental effects (i.e. personal experiences) also contribute substantially to the risk of suicidal behavior, whereas effects of shared (family) environment do not.
CONCLUSIONS
The totality of evidence from twin studies of suicide strongly suggests genetic contributions to liability for suicidal behavior. To further research progress in this area, an extensive discussion of design limitations, shortcomings of the literature and further points is provided, including sources of bias, gaps in the literature, errors in previous reviews, age and sex effects and twin-singleton differences in suicide risk, and notes from a history-of-science view.
Topics: Cause of Death; Diseases in Twins; Female; Genetic Predisposition to Disease; Humans; Male; Mental Disorders; Phenotype; Population Surveillance; Risk Factors; Social Environment; Suicide; Suicide, Attempted; Twin Studies as Topic; Twins, Dizygotic; Twins, Monozygotic
PubMed: 17721766
DOI: 10.1007/s00508-007-0823-2 -
Journal of Dentistry Aug 2023This review aimed to assess the agreement of dental caries experience between monozygotic (MZ) and dizygotic (DZ) twins. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
This review aimed to assess the agreement of dental caries experience between monozygotic (MZ) and dizygotic (DZ) twins.
DATA RESOURCES
This systematic review was performed by reviewers in the databases Embase, MEDLINE-PubMed, Scopus, Web of Science and manual searches and gray literature Google Scholar® and Opengray. Observational studies that evaluated dental caries in twins were included. The risk of bias was analyzed using the Joanna Briggs checklist. Meta-analyses were performed to assess the pooled Odds Ratio to estimate the agreement values of dental caries experience and DMF index between pairs of twins (p < 0.05). To assess the certainty of evidence, the GRADE scale was used.
STUDY SELECTION
2533 studies were identified, of which 19 were included in the qualitative analysis, six in the quantitative synthesis, with two meta-analyses being carried out. Association between genetics and the development of the disease was observed in most studies. In the risk of bias analysis, 47.4% had moderate risk. Higher agreement of dental caries experience was observed in MZ twins than DZ in both dentitions (OR: 5.94; 95% CI: 2.00-17.57). However, there was no difference between the MZ and DZ twin groups in the analysis comparing DMF index agreement (OR: 2.86; 95%CI: 0.25-32.79). The certainty of evidence was considered low and very low for all studies included in meta-analyses.
CONCLUSION
With very low certainty of the evidence, the genetic factor seems to influence the agreement of the caries experience.
CLINICAL RELEVANCE
Understanding the genetic influence on the disease has the potential to contribute to the development of studies that may use biotechnologies for prevention and treatment as well as guide future research involving gene therapies aiming to prevent the occurrence of dental caries.
Topics: Humans; Dental Caries; Bias; DMF Index; Odds Ratio
PubMed: 37339689
DOI: 10.1016/j.jdent.2023.104586 -
Birth Defects Research. Part A,... Mar 2012Isolated esophageal atresia (EA) is a rare congenital malformation whose etiology remains largely unknown. Nine twin pairs with EA were identified from our clinical... (Review)
Review
BACKGROUND
Isolated esophageal atresia (EA) is a rare congenital malformation whose etiology remains largely unknown. Nine twin pairs with EA were identified from our clinical service, prompting the performance of a systematic review of the literature and the first reported twin study of isolated EA.
METHODS
A total of 330 twin pairs with EA were identified from the literature. The zygosity, concordance, and malformation (isolated vs. nonisolated) status of all 339 twin pairs were evaluated. A total of 72 twin pairs (4 of 9 / 68 of 330) fulfilled the criteria for inclusion in a classic twin study of isolated EA.
RESULTS
The pairwise concordance rates were 50% (95% confidence interval [CI], 34-66%) for monozygous (MZ) twin pairs and 26% (95% CI, 15-42%) for dizygous (DZ) twin pairs (p = 0.033). The probandwise concordance rates were 67% (95% CI, 53-78%) for MZ twin pairs and 42% (95% CI, 29-56%) for DZ twin pairs (p = 0.011). The MZ/DZ ratios were 1.9 for pairwise analysis and 1.6 for probandwise analysis. The familial risk ratios for MZ and DZ twin pairs were 1700 and 900, respectively.
CONCLUSION
The observation of higher concordance rates for MZ compared to DZ twin pairs indicates that genetic factors contribute to isolated EA.
Topics: Diseases in Twins; Esophageal Atresia; Female; Genetic Predisposition to Disease; Humans; Male; Twins, Dizygotic; Twins, Monozygotic
PubMed: 22287212
DOI: 10.1002/bdra.22879