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Introduction: Twin–twin transfusion syndrome (TTTS) complicates approximately 10%–15% of all monochorionic twin pregnancies. The aim of this review was to evaluate the placental architectural characteristics within TTTS twins following laser and elucidate their impact on fetal outcomes and operative success. Material and Methods: Five databases were searched from inception to August 2023. Studies detailing post‐delivery placental analysis within TTTS twins post‐laser were included. Studies were categorized into two main groups: (1) residual anastomoses following laser and (2) abnormal cord insertion: either velamentous and/or marginal or proximate. The primary outcome was to determine the proportion of TTTS placentas with residual anastomoses and abnormal cord insertions post‐laser. Secondary outcomes included assessing residual anastomoses on post‐laser fetal outcomes and assessing the relationship between abnormal cord insertion and TTTS development. Study bias was critiqued using the Joanna Briggs Institute checklists and Cochrane risk of bias tool. Random‐effects meta‐analysis was used, and results were reported as pooled proportions or odds ratio (OR) with 95% confidence interval (CI). PROSPERO registration: CRD42023476875. Results: Twenty‐six studies, comprising 4013 monochorionic twins, were included for analysis. The proportion of TTTS placentas with residual anastomoses following laser was 24% (95% CI, 0.12–0.41), with a mean and standard deviation of 4.03 ± 2.95 anastomoses per placenta. Post‐laser residual anastomoses were significantly associated with intrauterine fetal death (OR, 2.38 [95% CI, 1.33–4.26]), neonatal death (OR, 3.37 [95% CI, 1.65–6.88]), recurrent TTTS (OR, 24.33 [95% CI, 6.64–89.12]), and twin anemia polycythemia sequence (OR, 13.54 [95% CI, 6.36–28.85]). Combined abnormal cord (velamentous and marginal), velamentous cord, and marginal cord insertions within one or both twins following laser were reported at rates of 49% (95% CI, 0.39–0.59), 27% (95% CI, 0.18–0.38), and 28% (95% CI, 0.21–0.36), respectively. Combined, velamentous and marginal cord insertions were not significantly associated with TTTS twins requiring laser (p = 0.72, p = 0.38, and p = 0.71, respectively) vs non‐TTTS monochorionic twins. Conclusions: To the best of our knowledge, this is the first review to conjointly explore outcomes of residual anastomoses and abnormal cord insertions within TTTS twins following laser. A large prospective study is necessitated to assess the relationship between abnormal cord insertion and residual anastomoses development post‐laser. [ABSTRACT FROM AUTHOR]

This series of three articles will explore the fundamentals related to anatomy, physiology and pathophysiology in relation to three important topics: the cardiac system, the respiratory system and the endocrine system. The series is intended to provide an informative and evidence-based summary of each topic for both students and clinicians. This first article explores the maternal cardiovascular system, outlining its anatomy and the key physiological adaptations of pregnancy, and summarising pathophysiological conditions that may occur. [ABSTRACT FROM AUTHOR]

Diseases involving dysfunction of smooth muscle cells present a major health and socioeconomic burden, and have remained stubbornly resistant to standard therapeutic strategies. Examples include many cardiovascular diseases and spontaneous preterm birth, a complication affecting up to 11% of all pregnancies worldwide. This fuels the continued search for new drug delivery strategies to treat these conditions. The use of cell penetrating peptides (CPPs) for this purpose remains a promising, if as yet unrealized, avenue to explore. In part, this may relate to a paucity of studies investigating the application of CPPs as drug delivery vectors to human smooth muscle cells and tissues. We have sought to address this knowledge gap by reporting methods for examining the uptake of different CPP-cargo vectors to human uterine and vascular smooth muscle cells. In particular, we report here (a) that four different CPP-fluorophore conjugates, spanning masses of 1309-3435 Da, and net charges of +2 to +7, can be delivered to human isolated uterine smooth muscle cells without inducing cell toxicity; (b) that the cargo delivered by such CPPs can be fluorescent moieties and/or biologically active peptides; (c) that CPP delivery in a short time frame to native smooth muscle cells in human tissues ex vivo can be achieved. Further exploration of CPPs as tools to facilitate targeted drug delivery to native human smooth muscle tissues will assist in improving our understanding of scientific mechanisms underlying major diseases involving smooth muscle dysfunction as well as facilitating therapeutic investigations., (© 2022. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)