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Journal of Perinatal Medicine May 2024To investigate factors associated with outcome of second twin during labour.
OBJECTIVES
To investigate factors associated with outcome of second twin during labour.
METHODS
The study was a retrospective cohort study in a single tertiary centre in Malaysia from 2014 until 2018 involving all twin pregnancies delivered at or more than 24 weeks of gestation.
RESULTS
Total of 409 twin pregnancies were included. Dichorionic twin comprises of 54.5 % (n=223) and 45.5 % (n=186) are monochorionic. Women with dichorionic pregnancies are significantly older (p<0.001), have more pre-existing medical disorders (p=0.011) and fetal structural anomalies (p=0.009). Monochorionic pregnancies are significantly more amongst Malay (p=0.01) and conceived spontaneously (p<0.001). There are significantly more fetuses both in cephalic presentation (p=0.026), birthweight discrepancy more than 20 % (p=0.038) and shorter mean inter-twin delivery duration (p=0.048) in monochorionic pregnancies. Second twin delivered with Apgar score <7 is significantly more in dichorionic pregnancies (p=0.006). The second twin is associated with lower birthweight, small for gestational age and arterial cord pH<7.25. Within the group of women who delivered both fetuses vaginally, there was significantly more second twins with intertwin delivery duration less than 30 min who were delivered vaginally without instrumentation (p=0.018). There was significantly more second twin with intertwin delivery duration of 30 min and more with arterial cord pH<7.25 (p=0.045). Those who delivered spontaneously had inter-twin delivery duration within 15-29 min. The outcome of second twin is not influenced by type of twin, gestational age at delivery, inter-twin delivery duration, mode of delivery and presentation at birth.
CONCLUSIONS
The neonatal outcome for the second twin at birth is not influenced by type of twin, gestational age at delivery, inter-twin delivery duration, mode of delivery and presentation at birth in a cohort managed with non-active management of the second twin in Malaysia.
Topics: Humans; Female; Pregnancy; Retrospective Studies; Malaysia; Pregnancy, Twin; Adult; Infant, Newborn; Pregnancy Outcome; Tertiary Care Centers; Birth Weight; Twins, Dizygotic
PubMed: 38511669
DOI: 10.1515/jpm-2023-0449 -
Twin Research and Human Genetics : the... Nov 2023Female fertility is a complex trait with age-specific changes in spontaneous dizygotic (DZ) twinning and fertility. To elucidate factors regulating female fertility and...
Female fertility is a complex trait with age-specific changes in spontaneous dizygotic (DZ) twinning and fertility. To elucidate factors regulating female fertility and infertility, we conducted a genome-wide association study (GWAS) on mothers of spontaneous DZ twins (MoDZT) versus controls (3273 cases, 24,009 controls). This is a follow-up study to the Australia/New Zealand (ANZ) component of that previously reported (Mbarek et al., 2016), with a sample size almost twice that of the entire discovery sample meta-analysed in the previous article (and five times the ANZ contribution to that), resulting from newly available additional genotyping and representing a significant increase in power. We compare analyses with and without male controls and show unequivocally that it is better to include male controls who have been screened for recent family history, than to use only female controls. Results from the SNP based GWAS identified four genomewide significant signals, including one novel region, (Zinc Finger Protein, FOG Family Member 1), on chromosome 16. Previous signals near (Follicle Stimulating Hormone beta subunit) and (SMAD Family Member 3) were also replicated (Mbarek et al., 2016). We also ran the GWAS with a dominance model that identified a further locus on chr 5. These results have been contributed to the International Twinning Genetics Consortium for inclusion in the next GWAS meta-analysis (Mbarek et al., in press).
PubMed: 37994447
DOI: 10.1017/thg.2023.45 -
Investigative Ophthalmology & Visual... Feb 2024Temporal-to-nasal macular ganglion cell layer thickness ratios are reduced in albinism. We explored similar ratios in a large twin cohort to investigate ranges in...
PURPOSE
Temporal-to-nasal macular ganglion cell layer thickness ratios are reduced in albinism. We explored similar ratios in a large twin cohort to investigate ranges in healthy adults, correlations with age, and heritability.
METHODS
More than 1000 twin pairs from TwinsUK underwent macular optical coherence tomography (OCT) scans. Automated segmentation yielded thicknesses for the combined ganglion cell and inner plexiform layer (GCIPL) in Early Treatment of Diabetic Retinopathy Study subfields. Participants with diseases likely to affect these layers or segmentation accuracy were excluded. Inner and outer ratios were defined as the ratio of temporal-to-nasal GCIPL thickness for inner and outer subfields respectively. Corresponding ratios were obtained from a smaller cohort undergoing OCTs with a different device (three-dimensional (3D)-OCT, Topcon, Japan).
RESULTS
Scans from 2300 twins (1150 pairs) were included (mean [SD] age, 53.9 (16.5) years). Mean (SD) inner and outer ratios were 0.89 (0.09) and 0.84 (0.11), correlating negatively with age (coefficients, -0.17 and -0.21, respectively). In males (150 pairs) ratios were higher and did not correlate significantly with age. Intrapair correlation coefficients were higher in monozygotic than dizygotic pairs; age-adjusted heritability estimates were 0.20 and 0.23 for inner and outer ratios, respectively. For the second cohort (n = 166), mean (SD) ratios were 0.93 (0.08) and 0.91 (0.09), significantly greater than for the larger cohort.
CONCLUSIONS
Our study gives reference values for temporal-to-nasal macular GCIPL subfield ratios. Weak negative correlations with age emerged. Genetic factors may contribute to ∼20% to 23% of the variance in healthy individuals. The ratios differ according to the OCT platform used.
Topics: Adult; Male; Humans; Middle Aged; Cross-Sectional Studies; Retina; Neurons; Diabetic Retinopathy; Nerve Fibers; Tomography, Optical Coherence
PubMed: 38349786
DOI: 10.1167/iovs.65.2.26 -
Obesity (Silver Spring, Md.) Dec 2023This study investigated 36-year BMI trajectories in twins whose BMI in young adulthood was below, within, or above their genetically predicted BMI, with a focus on twin...
OBJECTIVE
This study investigated 36-year BMI trajectories in twins whose BMI in young adulthood was below, within, or above their genetically predicted BMI, with a focus on twin pairs with large intrapair BMI differences (within-pair ΔBMI ≥ 3 kg/m ).
METHODS
Together, 3227 like-sexed twin pairs (34% monozygotic) were examined at age ~30 years in 1975 and followed up in 1981, 1990, and 2011. An individual's observed BMI in 1975 was considered within (±2.0), below (<-2.0), or above (>+2.0) genetically predicted BMI, measured by a polygenic risk score of 996,919 single nucleotide polymorphisms.
RESULTS
In monozygotic and dizygotic twin pairs with large intrapair BMI differences, the co-twin with a higher observed BMI in 1975 deviated above predicted BMI more frequently (~2/3) than the co-twin with a lower BMI deviated below prediction (~1/3). Individuals below, within, and above prediction in 1975 reached, respectively, normal weight, overweight, and obesity by 2011, with a mean BMI increase of 4.5 (95% CI: 4.3-4.8).
CONCLUSIONS
Categorizing BMI as below, within, or above polygenic risk score-predicted BMI helps identifying individuals who have been resistant or susceptible to weight gain. This may provide new insights into determinants and consequences of obesity.
Topics: Adult; Humans; Body Mass Index; Finland; Longitudinal Studies; Obesity; Twins, Dizygotic; Twins, Monozygotic; Male; Female
PubMed: 37987187
DOI: 10.1002/oby.23906 -
The International Journal of Eating... Oct 2023Eating disorders are associated with subsequent alcohol problems, but it is not known whether this association also extends to broader eating disorder symptoms not...
OBJECTIVE
Eating disorders are associated with subsequent alcohol problems, but it is not known whether this association also extends to broader eating disorder symptoms not captured by clinical diagnoses. We assessed the longitudinal association of broad eating disorder symptoms with alcohol problems in a nationwide twin sample (FinnTwin16).
METHODS
Finnish women (N = 1905) and men (N = 1449) self-reported their eating disorder symptoms using the Eating Disorder Inventory-2 Bulimia, Drive for Thinness, and Body Dissatisfaction subscales at the mean age of 24.4 years in 2000-2003. A subsample of participants also completed items on drive for muscularity, height dissatisfaction, and muscle-enhancing supplement use. Alcohol problems were assessed 10 years later at the age of 34.1 in 2010-2012 with the Rutgers Alcohol Problem Index.
RESULTS
Eating disorder symptoms were associated with later alcohol problems (odds ratio per point increase 1.02-1.18). Bulimia showed stronger associations among men than women (p for interaction .012). Drive for muscularity and height dissatisfaction were also associated with later alcohol problems, but supplement use was not. When accounting for baseline alcohol problems, only Bulimia (among women and men) and Drive for Thinness (among men) were significantly associated with later alcohol problems. Bulimia was also significantly associated with later alcohol problems in within-twin-pair analyses among dizygotic twins, but not among monozygotic twins.
DISCUSSION
In a longitudinal setting, eating disorder symptoms were associated with later alcohol problems. Bulimic symptoms were a stronger risk factor for men than women. These associations may be attributable to baseline alcohol problems, childhood environment and genetic liability.
PUBLIC SIGNIFICANCE
This study found that both young adult women and men with broad eating disorder symptoms are at a higher risk of alcohol-related problems than those without such symptoms. Men with bulimic symptoms were at a particularly high risk. These findings emphasize the need for better prevention and treatment of disordered eating, body image concerns and alcohol problems for both young adult women and men.
Topics: Adult; Child; Female; Humans; Male; Young Adult; Alcohol-Related Disorders; Body Image; Feeding and Eating Disorders; Finland; Follow-Up Studies; Thinness
PubMed: 37353472
DOI: 10.1002/eat.24013 -
European Journal of Orthodontics Nov 2023The objective of this study was to examine the relative contributions of genetic and environmental influences on variation in dental arch form in individuals who have...
OBJECTIVE
The objective of this study was to examine the relative contributions of genetic and environmental influences on variation in dental arch form in individuals who have largely completed their craniofacial growth.
MATERIAL AND METHODS
The subjects of this study comprised dental casts of 50 monozygotic twins and 24 dizygotic twins from the collection of records of twins housed at the Adelaide Dental School, Australia. The subjects were of Western European descent, with an average age of 20.93 ± 5.58 years. Dental casts were scanned using a 3D scanner to analyse the dental arch form. Landmark-based inter-arch and intra-arch measurements were performed. Structural equation modelling was employed to analyse the quantitative data using the normal assumptions of the twin model.
RESULTS
Genetic modelling revealed that additive genetic and unique environmental factors best explained the observed variation for all occlusal traits measured, except for mandibular intercanine width. High heritability was observed for most intra-arch occlusal variables (0.61-0.85) including the maxillary and mandibular intercanine and intermolar widths, arch depth and perimeter. In contrast, moderate heritability was found for inter-arch occlusal variables (0.52-0.59) such as overjet and overbite. Sexual dimorphism was evident, with males displaying larger posterior arch width than females (P < 0.05).
LIMITATIONS
Our sample was limited to individuals of Western European ancestry.
CONCLUSION
The predominant source of occlusal variation within this group of Australian twins of Western European descent was controlled by genetic effects, and most were highly heritable. Generally, intra-arch occlusal variables showed greater heritability compared with inter-arch occlusal variables.
Topics: Male; Female; Humans; Adolescent; Young Adult; Adult; Dental Arch; Australia; Malocclusion, Angle Class II; Overbite; Twins, Monozygotic
PubMed: 37861389
DOI: 10.1093/ejo/cjad054 -
BJOG : An International Journal of... Aug 2023To compare the neurodevelopmental outcomes of preterm twins at 5½ years by chorionicity of pregnancy.
OBJECTIVE
To compare the neurodevelopmental outcomes of preterm twins at 5½ years by chorionicity of pregnancy.
DESIGN
Prospective nationwide population-based EPIPAGE2 (Etude Epidémiologique sur les Petits Âges Gestationnels) cohort study.
SETTING
A total of 546 maternity units in France, between March and December 2011.
POPULATION
A total of 1126 twins eligible for follow-up at 5½ years.
METHODS
The association of chorionicity with outcomes was analysed using multivariate regression models.
MAIN OUTCOME MEASURES
Survival at 5½ years with or without neurodevelopmental disabilities (comprising cerebral palsy, visual, hearing, cognitive deficiency, behavioural difficulties or developmental coordination disorders) were described and compared by chorionicity.
RESULTS
Among the 1126 twins eligible for follow-up at 5½ years, 926 (82.2%) could be evaluated: 228 monochorionic (MC) and 698 dichorionic (DC). Based on chronicity and gestational age of birth, we found no significant differences for severe neonatal morbidity. The rates of moderate/severe neurobehavioral disabilities were similar in infants from DC pregnancies versus infants from MC pregnancies (OR 1.22, 95% CI 0.65-2.28). By gestational age and without twin-twin transfusion syndrome (TTTS), no difference according to chorionicity was found for all neurodevelopmental outcome measures.
CONCLUSIONS
The neurodevelopmental outcomes among preterm twins at 5½ years is similar, irrespective of chorionicity.
Topics: Infant, Newborn; Infant; Pregnancy; Humans; Female; Cohort Studies; Pregnancy Outcome; Prospective Studies; Twins, Monozygotic; Twins, Dizygotic; Gestational Age; Pregnancy, Twin; Retrospective Studies
PubMed: 37069725
DOI: 10.1111/1471-0528.17460 -
Early Human Development Jun 2024The commentary delves into the implications of "assortative parenting" and "assortative cross-parenting," as introduced by N. L. Segal, and situates these concepts...
The commentary delves into the implications of "assortative parenting" and "assortative cross-parenting," as introduced by N. L. Segal, and situates these concepts within the framework of current research. It addresses the joys and complexities of raising twins, highlighting how their concurrent development stages can amplify parental favoritism and heighten the challenge of addressing each twin's unique needs. This interplay provides a rich context to investigate assortative parenting practices. Additionally, this paper contemplates the broader picture of twin studies, particularly how the care of monozygotic twins (who share 100 % of their genes) and dizygotic twins (who share 50 % of their genes, on average) may reveal the intertwined nature of genetics and environment in parenting strategies. It also proposes that twins' interactions with other family members, their spouses, and peers can offer profound insights into the phenomena of phenotypic assortative affiliation, enriching our understanding of close relational bonds.
Topics: Child; Humans; Parent-Child Relations; Parenting; Parents; Twins, Monozygotic
PubMed: 38749092
DOI: 10.1016/j.earlhumdev.2024.106034 -
The Journal of Neuroscience : the... Feb 2024The functional connectome supports information transmission through the brain at various spatial scales, from exchange between broad cortical regions to finer-scale,...
The functional connectome supports information transmission through the brain at various spatial scales, from exchange between broad cortical regions to finer-scale, vertex-wise connections that underlie specific information processing mechanisms. In adults, while both the coarse- and fine-scale functional connectomes predict cognition, the fine scale can predict up to twice the variance as the coarse-scale functional connectome. Yet, past brain-wide association studies, particularly using large developmental samples, focus on the coarse connectome to understand the neural underpinnings of individual differences in cognition. Using a large cohort of children (age 9-10 years; = 1,115 individuals; both sexes; 50% female, including 170 monozygotic and 219 dizygotic twin pairs and 337 unrelated individuals), we examine the reliability, heritability, and behavioral relevance of resting-state functional connectivity computed at different spatial scales. We use connectivity hyperalignment to improve access to reliable fine-scale (vertex-wise) connectivity information and compare the fine-scale connectome with the traditional parcel-wise (coarse scale) functional connectomes. Though individual differences in the fine-scale connectome are more reliable than those in the coarse-scale, they are less heritable. Further, the alignment and scale of connectomes influence their ability to predict behavior, whereby some cognitive traits are equally well predicted by both connectome scales, but other, less heritable cognitive traits are better predicted by the fine-scale connectome. Together, our findings suggest there are dissociable individual differences in information processing represented at different scales of the functional connectome which, in turn, have distinct implications for heritability and cognition.
Topics: Humans; Male; Adult; Child; Female; Connectome; Reproducibility of Results; Magnetic Resonance Imaging; Brain; Cognition
PubMed: 38148152
DOI: 10.1523/JNEUROSCI.0735-23.2023 -
GeroScience Jul 2024There is abundant evidence that bone mineral content is highly heritable, while the heritability of bone quality (i.e. trabecular bone score [TBS] and quantitative...
There is abundant evidence that bone mineral content is highly heritable, while the heritability of bone quality (i.e. trabecular bone score [TBS] and quantitative ultrasound index [QUI]) is rarely investigated. We aimed to disentangle the role of genetic, shared and unique environmental factors on TBS and QUI among Hungarian twins. Our study includes 82 twin (48 monozygotic, 33 same-sex dizygotic) pairs from the Hungarian Twin Registry. TBS was determined by DXA, QUI by calcaneal bone ultrasound. To estimate the genetic and environmental effects, we utilized ACE-variance decomposition. For the unadjusted model of TBS, an AE model provided the best fit with > 80% additive genetic heritability. Adjustment for age, sex, BMI and smoking status improved model fit with 48.0% of total variance explained by independent variables. Furthermore, there was a strong dominant genetic effect (73.7%). In contrast, unadjusted and adjusted models for QUI showed an AE structure. Adjustments improved model fit and 25.7% of the total variance was explained by independent variables. Altogether 70-90% of the variance in QUI was related to additive genetic influences. We found a strong genetic heritability of bone quality in unadjusted models. Half of the variance of TBS was explained by age, sex and BMI. Furthermore, the adjusted model suggested that the genetic component of TBS could be dominant or an epistasis could be present. In contrast, independent variables explained only a quarter of the variance of QUI and the additive heritability explained more than half of all the variance.
PubMed: 38955996
DOI: 10.1007/s11357-024-01265-2