Twin studies for the prognosis,prevention and treatment of musculoskeletal conditions

Background

Musculoskeletal conditions are highly prevalent in our ageing society and are therefore incurring substantial increases in population levels of years lived with disability (YLD). An evidence-based approach to the prognosis, prevention, and treatment of those disorders can allow an overall improvement in the quality of life of patients, while also softening the burden on national health care systems.

Indicators of domestic/intimate partner violence are structured by genetic and nonshared environmental influences

One of the most consistent findings to emerge from domestic/intimate partner violence (IPV) research is that IPV tends to “run in the family.” Social learning theories appear to be consistent with empirical data, but almost no attention has been given to alternative explanations, including that genetic factors explain intergenerational transmission of IPV. Data for this study were drawn from wave 4 of the National Longitudinal Study of Adolescent Health (Add Health). Three indicators of IPV were measured and genetic factors accounted for 24% of the variance in hitting one's partner, 54% of the variance in injuring one's partner, and 51% of the variance in forcing sexual activity on one's partner. The shared environment explained none of the variance across all three indicators and the nonshared environment explained the remainder of the variance. These findings point to the importance of genetic factors in the etiology of IPV.     

Twin Anemia Polycythemia Sequence: Knowledge and Insights After 15 Years of Research

Twin anemia polycythemia sequence (TAPS) is a chronic form of unbalanced feto-fetal transfusion through minuscule placental anastomoses in monochorionic twin pregnancies, leading to anemia in the donor twin and polycythemia in the recipient twin. TAPS can occur spontaneously in up to 5% of monochorionic twins or can arise in 2%-16% of cases after incomplete laser surgery for twin-twin transfusion syndrome. TAPS can develop across the entire second and third trimester. Antenatal diagnosis for TAPS is reached via Doppler measurement of the fetal middle cerebral artery peak systolic velocity, showing an increased velocity in the donor, combined with a decreased velocity in the recipient. Treatment options for TAPS include expectant management, preterm delivery, intrauterine blood transfusion with or without a partial exchange transfusion, fetoscopic laser surgery and selective feticide. The best treatment option is unclear and is currently being investigated in an international multicenter randomized trial (the TAPS trial). Spontaneous fetal demise occurs in 5%-11% of TAPS twins, more often in donors (8%-18%) than in recipients (2%-5%). Severe long-term neurodevelopmental impairment is seen in 9% of TAPS twins, with donors having an increased risk for cognitive impairment and hearing problems (15%).     

Twin birth: The maternal experience

ObjectiveTwin birth is a special setting for women giving birth, and the experience of childbirth can be different from singleton birth. The objective of this study was to evaluate and compare the childbirth experiences of twin mothers and singleton mothers. We also aimed to identify the risk factors of a negative childbirth experience in the whole study population.MethodsAll live diamniotic twin deliveries in the study hospital of at least 35⁺⁰ weeks of gestation with a plan of vaginal birth were included in this matched groups study from August 2015 to August 2019. For every twin birth, two singleton birth controls were selected and matched with parity, the actual mode of birth, and gestational weeks at birth. Six weeks after birth, a Childbirth Experience Questionnaire (CEQ) was sent to mothers, and 72 twin mothers and 126 singleton mothers returned the questionnaire.ResultsThe twin mothers’ overall childbirth experience was positive. They reported a significantly lower opportunity to choose the birthing position (p < 0.001). Otherwise, there were no differences in the CEQ mean total scores between the study groups. Intrapartum cesarean section raised the risk of a negative childbirth experience and there was a high level of satisfaction with midwifery care among the whole study population.ConclusionThe overall maternal experience in planned vaginal twin birth was positive. Twin mothers felt less often able to choose their birthing position, otherwise the childbirth experience did not differ from that of singleton mothers.     

Can color difference on the maternal side of the placenta distinguish between acute peripartum twin–twin transfusion syndrome and twin anemia–polycythemia sequence?

ObjectiveTo investigate the color difference between two placental shares in monochorionic placentas with acute peripartum twin–twin transfusion syndrome (TTTS) and twin anemia–polycythemia sequence (TAPS).MethodsWe evaluated all digital pictures of TAPS, acute peripartum TTTS and a control group of uncomplicated monochorionic placentas examined at our center. We determined the color intensity of the individual placental share on the maternal side of each monochorionic placenta using an image–processing program and calculated the color difference ratio (CDR).ResultsDigital pictures of 5 acute peripartum TTTS, 25 TAPS and 54 control group placentas were included in this study. The median CDR in acute peripartum TTTS was significantly lower compared to TAPS placentas, 1.20 (inter-quartile range (IQR) 1.05–1.20) and 2.50 (IQR 1.85–3.34), respectively (p < 0.01), and was comparable to the control group (CDR 1.11, IQR 1.05–1.22).ConclusionTAPS placentas have a higher CDR compared to acute peripartum TTTS placentas. Examining color difference on the maternal side of the placenta might help distinguish between acute peripartum TTTS and TAPS.     

Placental abnormalities differ between small for gestational age fetuses in dichorionic twin and singleton pregnancies

ObjectiveTwin fetuses grow slower during the third trimester compared with singletons. However, the extent to which the relative smallness of twins is the result of placenta-mediated factors similar to those associated with fetal growth restriction in singletons remains unclear. Our aim was to address this question by comparing placental findings between small for gestational age (SGA) twins and SGA singletons.MethodsRetrospective cohort study of all SGA non-anomalous newborns from singleton and dichorionic twin pregnancies in a single tertiary referral center between 2002 and 2015. SGA was defined as birth weight <10th percentile for gestational age according to sex-specific national reference charts. Placental findings were compared between SGA twins and SGA singletons and were classified into lesions associated with maternal vascular malperfusion, fetal vascular malperfusion, placental hemorrhage and chronic villitis.ResultsA total of 532 SGA twins and 954 SGA singletons met the inclusion criteria. SGA twins had a higher mean placental weight (371 ± 103 g vs. 319 ± 107, p < 0.001) and a lower fetal-placental ratio (6.0 ± 2.5 vs. 6.7 ± 3.2, p < 0.001) compared with SGA singletons. Compared with SGA singletons, SGA twins were less likely to have any placental pathology (aOR 0.37, 95%-CI 0.29–0.46), hypercoiled cord (aOR 0.45, 95%-CI 0.33–0.61), placental weight<10th% (aOR 0.13, 95%-CI 0.08–0.20), maternal vascular malperfusion pathology (aOR 0.24, 95%-CI 0.18–0.30) and fetal vascular malperfusion pathology (aOR 0.62, 95%-CI 0.48–0.82). By contrast, SGA twins had higher odds of a marginal or velamentous cord insertion compared with SGA singletons (aOR 13.82, 95%-CI 10.44–18.30). Similar significant associations were observed in subgroups of SGA fetuses with a birth weight below the 5th and 3rd percentile for gestational age.ConclusionsOur findings illustrate that the mechanisms underlying reduced fetal growth in dichorionic twins differ from those involved in singletons, and may provide support to the hypothesis that smallness in dichorionic twins may be more benign than in singletons.     

Carbetocin versus oxytocin for prevention of postpartum hemorrhage in infertile women with twin pregnancy undergoing elective cesarean delivery

Objective

To compare the efficacy and safety of carbetocin with those of oxytocin infusion in women with twin pregnancy undergoing elective cesarean delivery.