Twin Group Research Articles

The transfer of double cleavage embryos developed from two four-cell embryos may not represent an optimal treatment strategy in cycles with a greater number of four-cell embryos on Day 2.

This study examined the impact of the number of Day 2 four-cell (D2-4C) embryos on double embryo transfer and blastocyst culture therapy in the first invitro fertilization (IVF) cycle. A retrospective review was performed on 1039 blastocyst culture cycles to compare outcomes between available and unavailable blastocyst cycles, emphasizing the relationship between the number of D2-4C embryos and blastocyst availability. Furthermore, the correlation between four-cell embryo counts and live births was analyzed in 986 transfer cycles. The analysis revealed that the number of D2-4C embryos independently influenced the availability of blastocysts (odds ratio [OR] 1.693, 95% confidence interval [CI] 1.306-2.195, P < 0.001). Receiver operating characteristic (ROC) analysis indicated that D2-4C embryos displayed the highest predictive value for available blastocysts, with an area under the curve (AUC) of 0.861 (95% CI 0.826-0.896). The cut-off point was determined to be 4.5, particularly for individuals younger than 25 years, where the AUC reached 0.927. This suggests that the number of D2-4C embryos has significant predictive value for available blastocysts. The live birth rate (LBR) of fresh embryo transfers significantly increased with the number of D2-4C embryos (P = 0.004). LBRs for zero, one, and two four-cell embryos in double cleavage embryo transfer were 20.24%, 34.97%, and 38.08%, respectively (P = 0.005). In the twin group, the percentages for zero, one, and two four-cell embryos were 1.21%, 9.75%, and 89.02%, respectively (P < 0.001). Single blastocyst transfer achieved an LBR comparable to that of two four-cell embryos (34.8% vs 39.0%, P = 0.415), while the twin rate significantly decreased with single blastocyst transfer (25.17% vs 1.40%, P < 0.001). The number of D2-4C embryos exhibits significant predictive value for available blastocysts, particularly among young women. Furthermore, most twins resulted from the transfer of double cleavage embryos derived from two four-cell embryos. Consequently, when the D2-4C count exceeds four in a cycle, blastocyst culture therapy is preferred over double cleavage-stage embryo transfer.

Regular Exercise Training Induces More Changes on Intestinal Glucose Uptake from Blood and Microbiota Composition in Leaner Compared to Heavier Individuals in Monozygotic Twins Discordant for BMI

Background/Objectives: Obesity impairs intestinal glucose uptake (GU) (intestinal uptake of circulating glucose from blood) and alters gut microbiome. Exercise improves intestinal insulin-stimulated GU and alters microbiome. Genetics influence the risk of obesity and gut microbiome. However, the role of genetics on the effects of exercise on intestinal GU and microbiome is unclear. Methods: Twelve monozygotic twin pairs discordant for BMI (age 40.4 ± 4.5 years, BMI heavier 36.7 ± 6.0, leaner 29.1 ± 5.7, 8 female pairs) performed a six-month-long training intervention. Small intestine and colonic insulin-stimulated GU was studied using [18F]FDG-PET and microbiota from fecal samples with 16s rRNA. Results: Ten pairs completed the intervention. At baseline, heavier twins had lower small intestine and colonic GU (p &lt; 0.05). Response to exercise differed between twins (p = 0.05), with leaner twins increasing colonic GU. Alpha and beta diversity did not differ at baseline. During the intervention, beta diversity changed significantly, most prominently at the mid-point (p &lt; 0.01). Beta diversity changes were only significant in the leaner twins when the twin groups were analyzed separately. Exercise was associated with changes at the phylum level, mainly at the mid-point (pFDR &lt; 0.05); at the genus level, several microbes increased, such as Lactobacillus and Sellimonas (pFDR &lt; 0.05). In type 1 analyses, many genera changes were associated with exercise, and fewer, such as Lactobacillus, were also associated with dietary sugar consumption (p &lt; 0.05). Conclusions: Obesity impairs insulin-stimulated intestinal GU independent of genetics. Though both twin groups exhibited some microbiota changes, most changes in insulin-stimulated colon GU and microbiota were significant in the leaner twins.

Planar doodles: Their properties, codes and classification

In this paper, we present those properties of planar doodles, especially when regarded as four-valent graphs, that enable us to classify them into prime and super-prime doodles by analogy to a knot sum. We describe a method for partially characterizing a doodle diagram by a doodle code that describes the complementary regions of the diagram and use that code to enumerate all possible prime and super-prime doodle diagrams via their dual graph. In addition, we explore the relationship between planar doodles and twin groups, and note that a theorem of Tutte means that super-prime doodles have a Hamiltonian circuit and we give examples of prime doodles without a Hamiltonian circuit.

Chorionicity and gestational diabetes mellitus in twin pregnancies in relation to placental weight

BackgroundGestational diabetes mellitus (GDM) is glucose intolerance first detected during pregnancy. Twin pregnancies have a higher risk of GDM, likely due to increased placental mass and elevated placental lactogen levels. ObjectiveThe aims of this study were 1) to assess the impact of chorionicity on the development of GDM in twin pregnancies and 2) to assess a possible association between placenta weight and the development of GDM. MethodsWe conducted a prospective cohort study of all women with twin pregnancies (N = 819) at the department of Obstetrics and Gynecology, Lillebaelt University Hospital, Kolding, Denmark, between January 1, 2007 and April 30, 2019. Information on chronicity was determined at the first visit with ultrasonic imaging, during weeks’ gestation 11–13. Oral glucose-tolerance test was performed to diagnose gestational diabetes mellitus. ResultsAmong 819 twins, 17.8 % were monochorionic twins and 82.2 % were dichorionic twins. There were no statistically significant difference of GDM prevalence between monochorionic twins group 7.4 % and dichorionic twins group 9.8 % (P = 0.42). Placenta's weight in dichorionic twins was larger compared with monochorionic twins. No association was found between the weight of placenta and the prevalence of GDM (P = 0.21), even after adjustment for body mass index, gestational age, and fertility treatment (P = 0.87). ConclusionsOur study could not find an association between chorionicity, placental weight, and GDM. It is, therefore, possible that twin pregnancies, regardless of chorionicity and placental weight, have the same risk for GDM.

The Effect of Assisted Reproductive Technology on Morbidity and Mortality of Twin Premature — A Secondary Publication

Objective: It is thought that twin neonates born from pregnancies resulting from assisted reproductive technology (ART) are clinically riskier than twin neonates born from spontaneous pregnancy. However, information on the risks in premature infants born as a result of ART pregnancies is limited. In our study, premature twin infants born from ART and spontaneous pregnancies were compared to clinical outcomes. Method: All premature twin infants hospitalized in our unit between September 2017 and September 2019 and born under 32 weeks of gestation were included in our study. Demographic and clinical results of premature twins born as a result of spontaneous and ART pregnancies were compared. Results: A total of 142 premature twins, 116 (81.6%) in the spontaneous twin group and 26 (18.4%) in the ART twin group, were included in the study. Demographic and clinical features were similar between ART and spontaneous twin groups (P &gt; 0.05). Conclusion: Our study determined that premature infants born due to ART pregnancies did not have any additional risk compared to spontaneous infants. This result shows that the main determinants of clinical outcomes in premature infants are gestational week and birth weight.

Outcome of Twins Discordant for Major Anomalies

Abstract Objectives This article determines the incidence, management, and outcomes of twins discordant for major structural anomalies. Materials and Methods A retrospective observational study was conducted from 2011 to 2021. Pregnant women discordant for major malformations as confirmed postnatally were included in the study. Demographic and clinical details were collected from medical records. Determining the incidence and profile of twins discordant for major structural anomalies and their management and outcomes were considered as primary objectives that were detailed in dichorionic (DC) and monochorionic (MC) twin pregnancies. Results A total of 83 subjects were included, with an incidence of 1.76% in DC pregnancies and 1.4% in MC pregnancies. Major structural anomalies among DC twins were musculoskeletal (26%), followed by circulatory system anomalies (20.2%), while among MC twins, the majority were found to be central nervous system anomalies (35.7%). Gastrointestinal system anomalies were found the least, with 5.8% in DC anomalous twins, and none were observed in MC anomalous twins. Live birth rate among anomalous twins was found to be 79.71 and 64.29%, and in normal cotwins, it was 92.75 and 85.71% in DC and MC twins, respectively. Surviving anomalous twins underwent postnatal surgery or intervention in 25/69 (36.2%) DC twins, out of which 20 infants were alive and healthy. In the MC anomalous twin group, 3/14 (21.42%) underwent surgical correction; all were alive and well. Postnatally, babies were followed up until 2 years of life. The survival rate for anomalous twins was 47.82% in DC and 35.7% in MC twins. Normal cotwins had overall favorable outcomes, with a survival rate of 89.8 and 85.7% in DC and MC twins, respectively. Conclusion In DC twins discordant for major anomalies, expectant management is a safe option.

Commutator subgroups and crystallographic quotients of virtual extensions of symmetric groups

The virtual braid group VBn, the virtual twin group VTn and the virtual triplet group VLn are extensions of the symmetric group Sn, which are motivated by the Alexander-Markov correspondence for virtual knot theories. The kernels of natural epimorphisms of these groups onto the symmetric group Sn are the pure virtual braid group VPn, the pure virtual twin group PVTn and the pure virtual triplet group PVLn, respectively. In this paper, we investigate commutator subgroups, pure subgroups and crystallographic quotients of these groups. We derive explicit finite presentations of the pure virtual triplet group PVLn, the commutator subgroup VTn′ of VTn and the commutator subgroup VLn′ of VLn. Our results complete the understanding of these groups, except that of VBn′, for which the existence of a finite presentation is not known for n≥4. We also prove that VLn/PVLn′ is a crystallographic group and give an explicit construction of infinitely many torsion elements in it.

Monozygotic twins discordant for schizophrenia differ in maturation and synaptic transmission.

Schizophrenia affects approximately 1% of the world population. Genetics, epigenetics, and environmental factors are known to play a role in this psychiatric disorder. While there is a high concordance in monozygotic twins, about half of twin pairs are discordant for schizophrenia. To address the question of how and when concordance in monozygotic twins occur, we have obtained fibroblasts from two pairs of schizophrenia discordant twins (one sibling with schizophrenia while the second one is unaffected by schizophrenia) and three pairs of healthy twins (both of the siblings are healthy). We have prepared iPSC models for these 3 groups of patients with schizophrenia, unaffected co-twins, and the healthy twins. When the study started the co-twins were considered healthy and unaffected but both the co-twins were later diagnosed with a depressive disorder. The reprogrammed iPSCs were differentiated into hippocampal neurons to measure the neurophysiological abnormalities in the patients. We found that the neurons derived from the schizophrenia patients were less arborized, were hypoexcitable with immature spike features, and exhibited a significant reduction in synaptic activity with dysregulation in synapse-related genes. Interestingly, the neurons derived from the co-twin siblings who did not have schizophrenia formed another distinct group that was different from the neurons in the group of the affected twin siblings but also different from the neurons in the group of the control twins. Importantly, their synaptic activity was not affected. Our measurements that were obtained from schizophrenia patients and their monozygotic twin and compared also to control healthy twins point to hippocampal synaptic deficits as a central mechanism in schizophrenia.

Vasoactive Management of Pulmonary Hypertension and Ventricular Dysfunction in Neonates Following Complicated Monochorionic Twin Pregnancies: A Single-Center Experience.

Twins resulting from a complicated monochorionic (MC) twin pregnancy are at risk for postnatal evolution of pulmonary hypertension (PH) and cardiac dysfunction (CD). Both pathologies are important contributors to short- and long-term morbidity in these infants. The aim of the present retrospective single-center cohort study was to evaluate the need for vasoactive treatment for PH and CD in these neonates. In-born neonates following a complicated MC twin pregnancy admitted to the department of neonatology of the University Children's Hospital Bonn (UKB) between October 2019 and December 2023 were screened for study inclusion. Finally, 70 neonates were included in the final analysis, with 37 neonates subclassified as recipient twins (group A) and 33 neonates as donor twins (group B). The overall PH incidence at day of life (DOL) 1 was 17% and decreased to 6% at DOL 7 (p = 0.013), with no PH findings at DOL 28. The overall incidence of CD was 56% at DOL 1 and decreased strongly until DOL 7 (10%, p = 0.015), with no diagnosis of CD at DOL 28. The use of dobutamine, norepinephrine, and vasopressin at DOL 1 until DOL 7 did not differ between the subgroups, whereas the dosing of milrinone was significantly higher in Group B at DOL 1 (p = 0.043). Inhaled nitric oxide (iNO) was used in 16% of the cohort, and a levosimendan therapy was administered in 34% of the neonates. One-third of the cohort was treated with oral beta blockers, and in 10%, an intravenous beta blockade (landiolol) was administered. The maximum levosimendan vasoactive-inotropic score (LVISmax) increased from DOL 1 (12.4 [3/27]) to DOL 2 (14.6 [1/68], p = 0.777), with a significant decrease thereafter as measured at DOL 7 (9.5 [2/30], p = 0.011). Early PH and CD are frequent diagnoses in neonates following a complicated MC twin pregnancy, and an individualized vasoactive treatment strategy is required in the management of these infants.

Exploring the genetic etiology across the continuum of the general psychopathology factor: a Swedish population-based family and twin study

Psychiatric comorbidity can be accounted for by a latent general psychopathology factor (p factor), which quantifies the variance that is shared to varying degrees by every dimension of psychopathology. It is unclear whether the entire continuum of the p factor shares the same genetic origin. We investigated whether mild, moderate, and extreme elevations on the p factor shared the same genetic etiology by, first, examining the linearity of the association between p factors across siblings (N = 580,891 pairs). Second, we estimated the group heritability in a twin sample (N = 17,170 pairs), which involves testing whether the same genetic variants influence both extreme and normal variations in the p factor. In both samples, the p factor was based on 10 register-based psychiatric diagnoses. Results showed that the association between siblings’ p factors appeared linear, even into the extreme range. Likewise, the twin group heritabilities ranged from 0.42 to 0.45 (95% CI: 0.33–0.57) depending on the thresholds defining the probands (2–3.33 SD beyond the mean; >2 SD beyond the mean; >4.33 SD beyond the mean; and >5.33 SD beyond the mean), and these estimates were highly similar to the estimated individual differences heritability (0.41, 95% CI: 0.39–0.43), indicating that scores above and below these thresholds shared a common genetic origin. Together, these results suggest that the entire continuum of the p factor shares the same genetic origin, with common genetic variants likely playing an important role. This implies, first, genetic risk factors for the aspect that is shared between all forms of psychopathology (i.e., genetic risk factors for the p factor) might be generalizable between population-based cohorts with a higher prevalence of milder cases, and clinical samples with a preponderance of more severe cases. Second, prioritizing low-cost genome-wide association studies capable of identifying common genetic variants, rather than expensive whole genome sequencing that can identify rare variants, may increase the efficiency when studying the genetic architecture of the p factor.

Pregnancy and obstetric outcomes of dichorionic triamniotic triplet pregnancies with selective foetal reduction after assisted reproductive technology

BackgroundIt is generally beneficial and recommended that dichorionic triamniotic (DCTA) triplet pregnancies be reduced to monochorionic (MC) twin or singleton pregnancies after assisted reproductive technology (ART). However, some infertile couples still have a firm desire to retain twins. For this reason, the best foetal reduction strategies need to be available for infertile couples and clinicians. Given that data on the elective reduction of DCTA triplet pregnancies to twin pregnancies are scarce, we investigated the outcomes of elective reduction of DCTA triplet pregnancies through the retrospective analysis of previous data.MethodPatients with DCTA triplet pregnancies who underwent elective foetal reduction between January 2012 and June 2020 were recruited. A total of 67 eligible patients with DCTA triplet pregnancies were divided into two groups: a DCTA-to-dichorionic diamniotic (DCDA) twin group (n = 38) and a DCTA-to-monochorionic diamniotic (MCDA) twin group (n = 29); the basic clinical data of the two groups were collected for comparison.ResultsCompared with the DCDA-to-MCDA twin group, the DCTA-to-DCDA twin group had lower rates of complete miscarriage (7.89% versus 31.03%, p = 0.014), early complete miscarriage (5.26% versus 24.14%, p = 0.034), late preterm birth (25.71% versus 65.00%, p = 0.009) and very low birth weight (0 versus 11.11%, p = 0.025). In addition, the DCTA-to-DCDA twin group had higher rates of full-term delivery (65.71% versus 25.00%, p = 0.005), survival (92.11% versus 68.97%, p = 0.023), and taking the babies home (92.11% versus 68.97%, p = 0.023) than did the DCTA-to-MCDA twin group. In terms of neonatal outcomes, a significantly greater gestational age (38.06 ± 2.39 versus 36.28 ± 2.30, p = 0.009), average birth weight (3020.77 ± 497.33 versus 2401.39 ± 570.48, p < 0.001), weight of twins (2746.47 ± 339.64 versus 2251.56 ± 391.26, p < 0.001), weight of the larger neonate (2832.94 ± 320.58 versus 2376.25 ± 349.95, p < 0.001) and weight of the smaller neonate (2660.00 ± 345.34 versus 2126.88 ± 400.93, p < 0.001) was observed in the DCTA-to-DCDA twin group compared to the DCTA-to-MCDA twin group.ConclusionThe DCTA-to-DCDA twin group had better pregnancy and neonatal outcomes than the DCTA-to-MCDA twin group. This reduction approach may be beneficial for patients with dichorionic triamniotic triplet pregnancies who have a strong desire to have DCDA twins.

Neonatal hemodynamics of recipient twins after fetoscopic selective laser coagulation for twin-to-twin transfusion syndrome: An unicist classification.

To characterize the neonatal hemodynamic profiles in recipients born after twin-to-twin transfusion syndrome (TTTS) treated with fetoscopic selective laser coagulation (FSLC). Retrospective analysis during the first month of life of recipient twins. Of the 480 newborns born during an 11-year period, 138 recipient twins with prenatal FSLC were classified into four groups: no hemodynamic impairment (NoHI, n = 102, 74%), isolated high blood pressure (HighBP, n = 18, 13%), right ventricular outflow tract obstruction (RVOTO, n = 10, 7%), and cardiac failure (CF, n = 8, 6%). The time (median (IQR)) between FSLC and birth was significantly shorter in the HighBP (36days (23-54)) and CF (44days (18-54)) groups than in the RVOTO (91days (68-112)) and NoHi (82days (62-104)) groups (p < 0.001). Conclusion:Four distinct and well-characterized groups of recipients were identified based on their hemodynamics. High blood pressure and heart failure occurred in approximately 20% of the infants and were associated with a time between laser coagulation and birth of less than 2months. What is Known: • Twin-to-twin transfusion syndrome (TTTS) is characterized by a hemodynamic imbalance that leads to high fetal and neonatal mortality if left untreated. One-third of recipient twins born without prenatal fetoscopic laser coagulation (FSLC) develop a life-threatening cardiac failure. What is New: • Four distinct groups of recipient twins with prenatal FSLC have been identified based on their hemodynamics. High blood pressure and cardiac failure occurred in 20% of the infants and were associated with an interval between FSLC and birth of less than 2months.

Long-Term Neurodevelopmental Outcome After Selective Fetoscopic Laser Therapy for Stage I Twin-Twin Transfusion Syndrome.

Twin-twin transfusion syndrome (TTTS) is a serious complication in monochorionic (MC) pregnancies. Fetoscopic laser surgery (FLS) is the primary treatment for advanced TTTS, but managing Quintero stage I TTTS is still controversial. We conducted an observational study evaluating the 2-year neurodevelopment of fetuses, which underwent FLS for stage I TTTS, compared with advanced TTTS and uncomplicated monochorionic diamniotic twins (MCDTs). The study included 156 children: 14 in stage I TTTS group, 28 in advanced TTTS group, and 114 in uncomplicated twin group. In stage I TTTS, 92.9% showed normal neurodevelopment, with no severe neurological impairments observed. These results were comparable with uncomplicated twins (92.1% normal neurodevelopment, P = .921, adjusted odds ratio [aOR] = 1.56, 95% confidence interval [CI] = 0.42-5.79; 1.8% severe impairment, P = .617). Advanced TTTS had a non-significant lower rate of normal neurodevelopment (89.3%, P = .710, aOR = 1.31, 95% CI = 0.12-14.87). In conclusion, FLS for stage I TTTS shows favorable long-term neurodevelopmental outcomes, similar to uncomplicated MC pregnancies.

Topologically nontrivial three-body contact interaction in one dimension

Abstract It is known that three-body contact interactions in one-dimensional (1D) n(≥3)-body problems of nonidentical particles can be topologically nontrivial: they are all classified by unitary irreducible representations of the pure twin group PTn. It was, however, unknown how such interactions are described in the Hamiltonian formalism. In this paper, we study topologically nontrivial three-body contact interactions from the viewpoint of the path integral. Focusing on spinless particles, we construct an n(n − 1)(n − 2)/3!-parameter family of n-body Hamiltonians that corresponds to one particular 1D unitary representation of PTn. These Hamiltonians are written in terms of background Abelian gauge fields that describe infinitely thin magnetic fluxes in the n-body configuration space.

Virtual planar braid groups and permutations

Abstract Twin groups and virtual twin groups are planar analogues of braid groups and virtual braid groups, respectively. These groups play the role of braid groups in the Alexander–Markov correspondence for the theory of stable isotopy classes of immersed circles on orientable surfaces. Motivated by the general idea of Artin and recent work of Bellingeri and Paris [P. Bellingeri and L. Paris, Virtual braids and permutations, Ann. Inst. Fourier (Grenoble) 70 (2020), 3, 1341–1362], we obtain a complete description of homomorphisms between virtual twin groups and symmetric groups, which as an application gives us the precise structure of the automorphism group of the virtual twin group VT n \mathrm{VT}_{n} on n ≥ 2 n\geq 2 strands. This is achieved by showing the existence of an irreducible right-angled Coxeter group KT n \mathrm{KT}_{n} inside VT n \mathrm{VT}_{n} . As a by-product, it also follows that the twin group T n \mathrm{T}_{n} embeds inside the virtual twin group VT n \mathrm{VT}_{n} , which is an analogue of a similar result for braid groups.

Litter size affects ovulation and pregnancy rate after a hormonal treatment without influencing expression of estrus in the anestrous season in ewes

The aim of this study was to determine if litter size affects the response to hormonal treatments for inducing estrus and ovulation during the non-breeding season. A total of 124 Corriedale ewes were utilized, consisting of 56 ewes that had given birth during the spring and were currently nursing either a single lamb (Single, n = 30) or twin lambs (Twin, n = 26). Additionally, a control group of ewes that had not given birth (Con, n = 68) was included. Estrus was induced 38 days after lambing using intravaginal sponges containing medroxyprogesterone acetate, which were left in place for 7 days. Furthermore, 350 IU of eCG was administered at the time of sponge removal. Upon detection of estrus, the ewes were inseminated, and transrectal ultrasonography was performed 8 and 40 days later to determine the presence of a corpus luteum (CL) and pregnancy, respectively. Expression of estrus did not differ due to postpartum status. However, a higher proportion of Con ewes than Twin ewes had a corpus luteum (P = 0.02), while the Single group did not differ from the other groups. Conception and pregnancy rates were higher in the Con group than in both, the Single and Twin groups (P ≤ 0.03). The litter size did not have a significant effect on the estrous response; however, postpartum status and/or lactation negatively impacted the pregnancy outcome.

Intertwin nuchal translucency difference predicts the chance of co-twin death after fetal reduction in dichorionic triplet pregnancies: a retrospective analysis study

ObjectivesTo compare the clinical outcomes of different multifetal pregnancy reduction (MFPR) programs in dichorionic (DC) triplets, and explore the association between early ultrasound characteristics and co-twin death after potassium chloride (KCl) injection into one monochorionic (MC) twin.MethodsWe retrospectively reviewed the data of DC triplets who underwent MFPR at our center during 2012–2021. Patients were grouped as follows: intracardiac KCl injection into one MC twin (group A), intracardiac KCl injection into both MC twins simultaneously (group B), and reduction of the singleton fetus (group C) and pregnancy outcomes were compared. Logistic regression was used to determine whether ultrasound measurements at 11–13+6 weeks predicted co-twin death and the receiver operator characteristic (ROC) analysis was conducted to assess the predictive performance.ResultsFinally, we enrolled 184 patients. 153 cases were in group A, and 18, 13 cases were in group B and C respectively. Gestational age at the time of MFPR did not differ among the 3 groups (median: 12^frac67 weeks). The survival rate was 89.6%, 88.9%, and 92.3% in group A, B, and C respectively, which was comparable among groups. Preterm birth was more common in group C (10/12, 83.3%). After KCl injection into one MC twin, co-twin death occurred in 86.3% cases (132/153) within 1 day; however, 3 patients had 2 live births each, with normal postnatal development. Intertwin nuchal translucency (NT) difference/discordance significantly predicted co-twin death within 1 day after MFPR, and the areas under the ROC curve were 0.694 and 0.689, respectively.ConclusionsFor MFPR in DC triplet pregnancies, reduction of the MC twins results in less preterm birth, and women with KCl injection into either one or both MC twins had similar outcomes. Large intertwin NT difference/discordance was associated with co-twin death within 1 day after KCl injection into one of the MC twins.

Risk factors associated with monozygotic twinning in offspring conceived by assisted reproductive technology.

What are the factors influencing the occurrence of monozygotic (MZ) twins in offspring conceived by assisted reproductive technology (ART)? Parental ages, the transfer of fresh versus frozen embryos, and the grade of blastocysts are all related to MZ twinning in ART offspring. Offspring conceived by ART have significantly increased risk of MZ twins, which may be due to the characteristics of the infertile population. The objective of this study was to explore the incidence of monozygotic (MZ) twins after ART and to clarify the risk factors for MZ twinning. A total of 255 monozygotic twins were enrolled in this cohort study, and then matched with singletons at a ratio of 1:4 randomly (with 1020 in the control group). All offspring were conceived by single embryo transfer. The collected data were divided into the following three aspects for analysis: characteristics of the infertile population, gamete or embryo manipulations, and factors related to embryo development. The incidence of MZ twins was 1.638% (255 out of 15 567 pregnancies after single embryo transfers). Compared to singleton births, a significantly lower rate of frozen embryo transfers (FET; 78.0% vs 86.1% P = 0.002) was seen amongst the MZ twins. Amongst fresh ETs, the rate of blastocyst transfers in the MZ twins group was higher compared to that in the control group (92.9% vs 75.4%, P = 0.005). We also found that certain grades of blastocysts in terms of trophectoderm (TE) development, inner cell mass + TE development and the classification of 'top-quality' embryos were associated with the incidence of MZ twinning (P = 0.025, P = 0.012, P = 0.020, respectively). Logistic regression analysis revealed that higher paternal age (odds ratio (OR) = 0.94, 95% CI = 0.89-1.00, P = 0.029) and FET (OR = 0.48, 95% CI = 0.33-0.68, P = 0.001) may be protective factors against MZ twinning. However, higher maternal age (OR = 1.07, 95% CI = 1.01-1.13, P = 0.027) and the transfer of blastocysts (OR = 4.31, 95% CI = 1.46-12.73, P = 0.008) appeared to be associated with an increased risk of MZ twinning. Amongst blastocyst transfers, a C grade TE may be protective factor against MZ twinning (B: OR = 1.90, 95% CI = 1.18-3.07, P = 0.009; A: OR = 1.58, 95% CI = 0.93-2.67, P = 0.089). First, our definition of MZ twins was based on twins' birth after single embryo transfers (SET), rather than ultrasound examination during early pregnancy. Second, the parental characteristics of the two groups were homogenous, so it was difficult to find any associations between infertility factors and the incidence of MZ twins. This multifaceted analysis of the risk factors for MZ twinning provides some information for clinical interventions in high-risk populations. This study was supported by the National Key Technology Research and Developmental Program of China (2022YFC2704404), CAMS Innovation Fund for Medical Sciences (2021-I2M-5-001), Taishan Scholars Program for Young Experts of Shandong Province (tsqn201909195), the Basic Science Center Program (31988101), and the Shandong Provincial Key Research and Development Program (2020ZLYS02). All authors have no conflicts of interest to declare. N/A.

Longitudinal Child Growth Patterns in Twins and Singletons in the Upstate KIDS Cohort

To investigate childhood growth patterns in twins and to determine whether they show the same signs of excess growth as singletons born small-for-gestational age (SGA), which may confer future cardiometabolic risk. In the Upstate KIDS cohort of infants delivered from 2008 through 2010, we compared height, weight, and body mass index (BMI) z-scores at 0-3 and 7-9years of age, as well as risk of rapid weight gain (RWG) in infancy and overweight/obesity beginning at 2years, among appropriate-for-gestational age (AGA) twins (n=1121), AGA singletons (n=2684), and two groups of SGA twins: uncertain SGA twins (<10th percentile for birthweight by a singleton reference but >10th% by a population-based twin birthweight reference; n=319) and true SGA twins (<10th% by a population-based twin reference; n=144). Compared with AGA twins, both SGA twin groups had lower weight and BMI z-scores at both time points. By 7-9years, both groups caught up in height with AGA twins. Compared with AGA singletons, z-score differences decreased between 0-3 and 7-9years for uncertain SGA and true SGA twins, though true SGA twins had the lowest z-scores for all measures. During infancy, twins were more likely to display RWG compared with AGA singletons (RR=2.06 to 2.67), which may reflect normal catch-up growth, as no twin group had higher prevalence of overweight/obesity at either time point. Though twins had lower height, weight, and BMI z-scores at birth and into toddlerhood, differences were reduced by 7-9years, with no evidence of pathological growth and no group of twins showing elevated risk of overweight/obesity.

Literature review of digital twin in healthcare

This article aims to make a bibliometric literature review using systematic scientific mapping and content analysis of digital twins in healthcare to know the evolution, domain, keywords, content type, and kind and purpose of digital twin's implementation in healthcare, so a consolidation and future improvement of existing knowledge can be made and gaps for new studies can be identified.The increase in publications of digital twins in healthcare is quite recent and it is still concentrated in the domain of technology sources. The subject is majorly concentrated in patient's digital twin group and in precision medicine and aspects, issues and/or policies subgroups, although the publications keywords mirror it only at the group side. Digital twins in healthcare are probably stepping out of the infancy phase. On the other hand, digital twins in hospital group and the device and facilities management subgroups are more mature with all knowledge gathered from the manufacturing sector. There is an absence of some publication's types in general, device and care subgroup and no whole body or hospital digital twin was reported. Based on the presented arguments, guidelines for future research were presented: advance in the creation of general frameworks, in subgroups not as much explored, and in groups and subgroups already explored, but that need more advancement to achieve the main goals of a whole human or hospital digital twin with the main issues resolved.