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Journal of Assisted Reproduction and... Jun 2020Binovular follicles including a pair of conjoined oocytes within a common zona pellucida or their fusion in the zonal region gained some attentions due to its possible...
PURPOSE
Binovular follicles including a pair of conjoined oocytes within a common zona pellucida or their fusion in the zonal region gained some attentions due to its possible role in dizygotic twins. Although some cases in the literature been reported in which two conjoined oocytes arising from binovular follicles were mature, and injected with two separated sperm, no available evidence reported for dizygotic twin pregnancies.
METHODS
A case report of a 37-year-old female patient underwent embryo transfer cycle whereby a pair of conjoined blastocysts after ICSI of a pair of conjoined oocytes was transferred.
RESULTS
The β-hCG level was positive 15 days after embryo transfer. The subsequent pregnancy scan revealed a dizygotic pregnancy. The woman gave birth to two healthy boys in the mid of 38 weeks of gestation by cesarean section.
CONCLUSIONS
Given the insufficient evidence on how to handle conjoined oocytes, this report acknowledges the first occurrence of dizygotic twin delivery resulted from transfer of a pair of conjoined blastocysts after ICSI of a pair of conjoined oocytes. This also confirms that we should be extremely conservative in discarding any mature oocyte without sufficient data about its useless future to result in a healthy baby.
Topics: Adult; Blastocyst; Cesarean Section; Chorionic Gonadotropin, beta Subunit, Human; Embryo Transfer; Female; Fertilization in Vitro; Humans; Live Birth; Male; Oocytes; Pregnancy; Sperm Injections, Intracytoplasmic; Twins, Dizygotic; Zona Pellucida
PubMed: 32285296
DOI: 10.1007/s10815-020-01772-z -
Proceedings of the Institution of... Aug 2021Gait analysis and gait indices are frequently used to evaluate gait pathologies and outcomes. The aim of this study is to investigate the differences in gait parameters...
Gait analysis and gait indices are frequently used to evaluate gait pathologies and outcomes. The aim of this study is to investigate the differences in gait parameters of dizygotic twin athletes according to each other and athletes group who are similar age but non-twin. Eighty-four athletes without any disease that could cause gait pathology were included the study. Time-distance measurements, kinematic - kinetic variables, and gait deviation index (GDI) of the gait functions of twin athletes (17 boys and 25 girls, height: 153.9 ± 15 cm, weight: 45.9 ± 12 kg, leg length 80.5 ± 11 cm) were compared with each other and with 42 sex and age matched non-twins athletes (height: 155 ± 15 cm, weight: 47 ± 14 kg, leg length 80.6 ± 9.8 cm, mean age 11.8 ± 2.29, range 6-15 years). No statistically significant difference was found about the time, distance parameters and GDIs in comparison of twin athletes with each other and the non-twin group. Additionally, kinetic and kinematic variables were similar in between twins. We measured lower adduction angles and higher abduction angles in non-twin athletes in comparison to the twin athletes ( = 0.01, 0.04). Additionally, the angle of knee flexion at the first contact was higher in non-twins ( = 0.003).Being dizygotic twin seems to have no clinical effect on gait function in athletes.
Topics: Adolescent; Athletes; Biomechanical Phenomena; Child; Female; Gait; Gait Analysis; Humans; Male; Twins, Dizygotic
PubMed: 33928809
DOI: 10.1177/09544119211012495 -
Clinical and Experimental Dermatology Dec 2021
Topics: Diseases in Twins; Ectodermal Dysplasia; Female; Genes, Dominant; Heterozygote; Humans; Infant, Newborn; Male; Oocyte Donation; Twins, Dizygotic
PubMed: 34048064
DOI: 10.1111/ced.14763 -
Twin Research and Human Genetics : the... Feb 2009A forgotten story of monozygotic twins reared apart is described. The pair, born in 1941 in Fribourg, Switzerland, were separated due to switch-baby incident in the... (Review)
Review
Twins reared apart: a forgotten case/twin research reviews: X-inactivation and female co-twin discordance for hemophilia; transplantation for breast reconstruction; chimerism and telomere attrition in dizygotic twins; divergent life histories in twins reared apart/current concerns: high ACT-scoring...
A forgotten story of monozygotic twins reared apart is described. The pair, born in 1941 in Fribourg, Switzerland, were separated due to switch-baby incident in the hospital. This caused one twin to be raised as a singleton by an unrelated family, and the other twin to be raised as a 'dizygotic' twin with an unrelated child. This is followed by reviews of recent twin research and case studies of X-inactivation and hemophilia, breast reconstruction, chimerism and life histories. The final section of the article includes human interest pieces on academic twins, dating twins, transsexual twins and athletic twins.
Topics: Hemophilia A; History, 20th Century; Humans; Organ Transplantation; Sex Characteristics; Telomere; Transplantation Chimera; Twin Studies as Topic; Twins, Dizygotic
PubMed: 19210188
DOI: 10.1375/twin.12.1.123 -
Journal of Assisted Reproduction and... Apr 2014
Review
Topics: Adult; Female; Humans; Male; Pregnancy; Pregnancy, Twin; Single Embryo Transfer; Twins, Dizygotic
PubMed: 24390628
DOI: 10.1007/s10815-013-0170-3 -
Twin Research and Human Genetics : the... Jun 2020This article describes a 1930s case study series involving dizygotic female twin infants. The twins' development was evaluated following periods of intentionally...
Dizygotic Twin Infants: Controversial Case Study Series/Twin Research Reviews: Twin and Non-twin ICSI Conceptions; Emory University Twin Study; Labor in Multiple Pregnancy After Previous C-Section Delivery; Cell-Free DNA Fetal Fraction in Twin Pregnancies/News Reports: Twin Survivor of Auschwitz;...
This article describes a 1930s case study series involving dizygotic female twin infants. The twins' development was evaluated following periods of intentionally restricted practice and minimal social stimulation. In the opinion of the author of the current article, the study is very unsettling and unacceptable, despite the lack of institutional review boards at that time. This discussion is followed by twin research reviews of recent papers concerning twin and non-twin intracytoplasmic sperm injection conceptions, the Emory University Twin Study of cardiac and brain functions, labor trials in multiple pregnancies after previous C-section delivery and cell-free DNA fetal fraction in twin pregnancies. The article concludes with news items of a twin survivor of Auschwitz, a situation in which twins traded places, the rare birth of identical twin foals, the novel delivery of co-twins in different decades and the Twins Ambulette Service.
Topics: Cell-Free Nucleic Acids; Female; Humans; Infant; Pregnancy; Pregnancy, Twin; Twin Studies as Topic; Twins, Dizygotic; Twins, Monozygotic
PubMed: 32539898
DOI: 10.1017/thg.2020.50 -
BMC Psychology Jan 2022In the general population, 10.6% of people favor their left hand over the right for motor tasks. Previous research suggests higher prevalence of atypical (left-, mixed-,... (Meta-Analysis)
Meta-Analysis
BACKGROUND
In the general population, 10.6% of people favor their left hand over the right for motor tasks. Previous research suggests higher prevalence of atypical (left-, mixed-, or non-right-) handedness in (i) twins compared to singletons, and in (ii) monozygotic compared to dizygotic twins. Moreover, (iii) studies have shown a higher rate of handedness concordance in monozygotic compared to dizygotic twins, in line with genetic factors playing a role for handedness.
METHODS
By means of a systematic review, we identified 59 studies from previous literature and performed three sets of random effects meta-analyses on (i) twin-to-singleton Odds Ratios (21 studies, n = 189,422 individuals) and (ii) monozygotic-to-dizygotic twin Odds Ratios (48 studies, n = 63,295 individuals), both times for prevalence of left-, mixed-, and non-right-handedness. For monozygotic and dizygotic twin pairs we compared (iii) handedness concordance Odds Ratios (44 studies, n = 36,217 twin pairs). We also tested for potential effects of moderating variables, such as sex, age, the method used to assess handedness, and the twins' zygosity.
RESULTS
We found (i) evidence for higher prevalence of left- (Odds Ratio = 1.40, 95% Confidence Interval = [1.26, 1.57]) and non-right- (Odds Ratio = 1.36, 95% Confidence Interval = [1.22, 1.52]), but not mixed-handedness (Odds Ratio = 1.08, 95% Confidence Interval = [0.52, 2.27]) among twins compared to singletons. We further showed a decrease in Odds Ratios in more recent studies (post-1975: Odds Ratio = 1.30, 95% Confidence Interval = [1.17, 1.45]) compared to earlier studies (pre-1975: Odds Ratio = 1.90, 95% Confidence Interval = [1.59-2.27]). While there was (ii) no difference between monozygotic and dizygotic twins regarding prevalence of left- (Odds Ratio = 0.98, 95% Confidence Interval = [0.89, 1.07]), mixed- (Odds Ratio = 0.96, 95% Confidence Interval = [0.46, 1.99]), or non-right-handedness (Odds Ratio = 1.01, 95% Confidence Interval = [0.91, 1.12]), we found that (iii) handedness concordance was elevated among monozygotic compared to dizygotic twin pairs (Odds Ratio = 1.11, 95% Confidence Interval = [1.06, 1.18]). By means of moderator analyses, we did not find evidence for effects of potentially confounding variables.
CONCLUSION
We provide the largest and most comprehensive meta-analysis on handedness in twins. Although a raw, unadjusted analysis found a higher prevalence of left- and non-right-, but not mixed-handedness among twins compared to singletons, left-handedness was substantially more prevalent in earlier than in more recent studies. The single large, recent study which included birth weight, Apgar score and gestational age as covariates found no twin-singleton difference in handedness rate, but these covariates could not be included in the present meta-analysis. Together, the secular shift and the influence of covariates probably make it unsafe to conclude that twinning has a genuine relationship to handedness.
Topics: Birth Weight; Functional Laterality; Humans; Prevalence; Twins, Dizygotic; Twins, Monozygotic
PubMed: 35033205
DOI: 10.1186/s40359-021-00695-3 -
Twin Research and Human Genetics : the... Dec 2019The South Korean Twin Registry (SKTR) is an ongoing nationwide volunteer registry of South Korean twins and their families. Since its inception, from preschooler to...
The South Korean Twin Registry (SKTR) is an ongoing nationwide volunteer registry of South Korean twins and their families. Since its inception, from preschooler to young adult, twins have been registered with the SKTR and have demonstrated that relative influences of genetic and environmental factors explaining individual differences in various psychological, mental health and physical traits in South Koreans are similar to those found in many Western twin studies. Currently, studies at the SKTR focus on identification of the process of gene-by-environment interactions as well as developmental differences in genetic and environmental influences on psychological and mental health traits in South Koreans. This report provides a brief overview, recruitment strategies, current samples, zygosity assessment, measures and future directions of the SKTR.
Topics: Adolescent; Adult; Child; Diseases in Twins; Female; Follow-Up Studies; Gene-Environment Interaction; Humans; Male; Models, Genetic; Registries; Republic of Korea; Twins, Dizygotic; Twins, Monozygotic; Young Adult
PubMed: 31875802
DOI: 10.1017/thg.2019.115 -
Cold Spring Harbor Perspectives in... Jun 2021In this review, we discuss how samples comprising monozygotic and dizygotic twin pairs can be used for the purpose of strengthening causal inference by controlling for... (Review)
Review
In this review, we discuss how samples comprising monozygotic and dizygotic twin pairs can be used for the purpose of strengthening causal inference by controlling for shared influences on exposure and outcome. We begin by briefly introducing how twin data can be used to inform the biometric decomposition of population variance into genetic, shared environmental, and nonshared environmental influences. We then discuss how extensions to this model can be used to explore whether associations between exposure and outcome survive correction for shared etiology (common causes). We review several analytical approaches that can be applied to twin data for this purpose. These include multivariate structural equation models, cotwin control methods, direction of causation models (cross-sectional and longitudinal), and extended family designs used to assess intergenerational associations. We conclude by highlighting some of the limitations and considerations that researchers should be aware of when using twin data for the purposes of interrogating causal hypotheses.
Topics: Disease; Environmental Exposure; Humans; Twins, Dizygotic; Twins, Monozygotic
PubMed: 32900702
DOI: 10.1101/cshperspect.a039552 -
Nature Mar 2002It has been suggested that losses of twin conceptuses in very early pregnancy are high, and that for every liveborn twin pair there are a further 10-12 twin pregnancies...
It has been suggested that losses of twin conceptuses in very early pregnancy are high, and that for every liveborn twin pair there are a further 10-12 twin pregnancies that end up as a singleton birth. Here we show that in a group of women who had double-ovulated and conceived, the probability of the second egg also becoming fertilized and developing is 20-30% - which is comparable to the probability of conception and survival of a single conceptus. We conclude that the presence of one embryo does not affect the development of its twin.
Topics: Embryo Loss; Female; Humans; Models, Biological; Ovulation Detection; Pregnancy; Survival Rate; Twins, Dizygotic; Ultrasonography, Doppler
PubMed: 11894085
DOI: 10.1038/416142a