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American Journal of Medical Genetics.... Mar 2019Twins, particularly monochorionic (MC) pairs, are at increased risk for fetal death. Whereas previous work has sought to understand the mechanisms for this increased...
Twins, particularly monochorionic (MC) pairs, are at increased risk for fetal death. Whereas previous work has sought to understand the mechanisms for this increased mortality, most studies analyze viable twin pregnancies or liveborn twin cohorts. In the Wisconsin Stillbirth Service Program cohort of 3,137 stillbirths and second trimester miscarriages, we identified 175 twin pregnancies for a twinning rate of 56/1,000, which is approximately double the general population. The excess of twins among miscarriages and stillbirths was attributable to MC pairs as the incidence of dizygotic (DZ) twinning was not increased compared to livebirth data. The leading causes of fetal demise among twins were twin-twin transfusion, acardia, and twin-twin disruption. Maternal causes of death, primarily premature rupture of membranes, were moderately increased in both MC and DZ twins relative to singletons. Although deceased twins were smaller than expected for viable twins at comparable gestational ages, placenta weights of deceased MC pairs were large compared to combined fetal weight, which indicates placental inefficiency likely due to vascular shunting. Co-twin survival was much lower for MC than for DZ pairs. Therefore, earlier diagnosis and treatment of MC twinning complications may decrease prenatal mortality.
Topics: Abortion, Spontaneous; Cause of Death; Databases, Factual; Female; Fetal Death; Health Surveys; Humans; Pregnancy; Pregnancy Trimester, Second; Pregnancy, Twin; Prevalence; Stillbirth; Twins, Dizygotic; Twins, Monozygotic; Wisconsin
PubMed: 30663217
DOI: 10.1002/ajmg.a.61014 -
Fetal and Pediatric Pathology 2015Pseudomonoamniotic gestations are increasingly recognized through sonographic surveillance of monochorionic twins, though etiologic factors remain undefined. We present... (Review)
Review
Pseudomonoamniotic gestations are increasingly recognized through sonographic surveillance of monochorionic twins, though etiologic factors remain undefined. We present a case of spontaneous pseudomonoamniotic twins and propose umbilical cord insertion proximity as a sonographic marker. Systematic review of the literature was performed and additional cases with similar findings were noted. Approximately 75% of reported cases (28/37) were deemed spontaneous and several included short inter-cord distances. Shunting of blood away from the membranes in the region between the cord insertions may be responsible for membrane rupture. Further investigation is needed into short inter-cord distance as a marker for monochorionic twins at risk to become a pseudomonoamniotic gestation.
Topics: Adult; Amnion; Chorion; Diseases in Twins; Female; Humans; Pregnancy; Pregnancy, Twin; Twins, Monozygotic; Umbilical Cord
PubMed: 26359803
DOI: 10.3109/15513815.2015.1075633 -
Neuroscience and Biobehavioral Reviews Dec 2019The debate upon the relative importance of nature vs nurture in the development of human behaviour can be traced back to ancient times. Traditional epidemiology and...
The debate upon the relative importance of nature vs nurture in the development of human behaviour can be traced back to ancient times. Traditional epidemiology and genetic epidemiology have confirmed the association of environmental and genetic factors with behavioural traits. Current genomic studies are identifying genetic variants associated with various behavioural traits. However, exploring the relationship of abundant environmental factors with the complex epigenome that mediates human behaviour is just at its beginning. Identical twins can serve as perfect experiments for studying the environmental impact on behavioural epigenetics advantaged by enriched power in association analysis due to controlling of their genetic make-ups. Recent development in causal inference using twin-based models adds more values in twins. This review briefly introduces the various approaches in making use of twins in studying behavioural epigenetics from experiment design to practical applications. Exploring the epigenome of twins using the powerful twin-based study designs and analytical approaches will help identifying causal epigenetic markers mediating environmental exposures and behavioural traits enabling both pharmaceutical intervention and effective prevention.
Topics: Epigenesis, Genetic; Epigenome; Humans; Phenotype; Twin Studies as Topic; Twins, Monozygotic
PubMed: 31536737
DOI: 10.1016/j.neubiorev.2019.09.022 -
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 -
Neuroscience and Biobehavioral Reviews May 2020Monozygotic (MZ) twin studies constitute a key resource for the dissection of environmental and biological risk factors for human complex disorders. Given that...
Monozygotic (MZ) twin studies constitute a key resource for the dissection of environmental and biological risk factors for human complex disorders. Given that epigenetic differences accumulate throughout the lifespan, the assessment of MZ twin pairs discordant for depression offers a genetically informative design to explore DNA methylation while accounting for the typical confounders of the field, shared by co-twins of a pair. In this review, we systematically evaluate all twin studies published to date assessing DNA methylation in association with depressive phenotypes. However, difficulty to recruit large numbers of MZ twin pairs fails to provide enough sample size to develop genome-wide approaches. Alternatively, region and pathway analysis revealed an enrichment for nervous system related functions; likewise, evidence supports an accumulation of methylation variability in affected subjects when compared to their co-twins. Nevertheless, longitudinal studies incorporating known risk factors for depression such as childhood trauma are required for understanding the role that DNA methylation plays in the etiology of depression.
Topics: DNA Methylation; Depression; Depressive Disorder; Epigenesis, Genetic; Humans; Twin Studies as Topic
PubMed: 32068032
DOI: 10.1016/j.neubiorev.2020.02.017