An exploratory open-label multicentre phase I/II trial evaluating the safety and efficacy of postnatal or prenatal and postnatal administration of allogeneic expanded fetal mesenchymal stem cells for the treatment of severe osteogenesis imperfecta in infants and fetuses: the BOOSTB4 trial protocol.

INTRODUCTION: Severe osteogenesis imperfecta (OI) is a debilitating disease with no cure or sufficiently effective treatment. Mesenchymal stem cells (MSCs) have good safety profile, show promising effects and can form bone. The Boost Brittle Bones Before Birth (BOOSTB4) trial evaluates administration of allogeneic expanded human first trimester fetal liver MSCs (BOOST cells) for OI type 3 or severe type 4. METHODS AND ANALYSIS: BOOSTB4 is an exploratory, open-label, multiple dose, phase I/II clinical trial evaluating safety and efficacy of postnatal (n=15) or prenatal and postnatal (n=3, originally n=15) administration of BOOST cells for the treatment of severe OI compared with a combination of historical (1-5/subject) and untreated prospective controls (≤30). Infants<18 months of age (originally<12 months) and singleton pregnant women whose fetus has severe OI with confirmed glycine substitution in COL1A1 or COL1A2 can be included in the trial.Each subject receives four intravenous doses of 3×106/kg BOOST cells at 4 month intervals, with 48 (doses 1-2) or 24 (doses 3-4) hours in-patient follow-up, primary follow-up at 6 and 12 months after the last dose and long-term follow-up yearly until 10 years after the first dose. Prenatal subjects receive the first dose via ultrasound-guided injection into the umbilical vein within the fetal liver (16+0 to 35+6 weeks), and three doses postnatally.The primary outcome measures are safety and tolerability of repeated BOOST cell administration. The secondary outcome measures are number of fractures from baseline to primary and long-term follow-up, growth, change in bone mineral density, clinical OI status and biochemical bone turnover. ETHICS AND DISSEMINATION: The trial is approved by Competent Authorities in Sweden, the UK and the Netherlands (postnatal only). Results from the trial will be disseminated via CTIS, ClinicalTrials.gov and in scientific open-access scientific journals. TRIAL REGISTRATION NUMBERS: EudraCT 2015-003699-60, EUCT: 2023-504593-38-00, NCT03706482.

Changing epidemiology of parvovirus B19 in the Netherlands since 1990, including its re-emergence after the COVID-19 pandemic.

Parvovirus B19V (B19V) infection during pregnancy can be complicated by potentially life-threatening fetal hydrops, which can be managed by intrauterine transfusion (IUT). This study investigates the long-term temporal patterns in the epidemiology of B19V and evaluates the impact on fetal hydrops, by combining data on B19V infections from the Dutch Sentinel Surveillance system in the period 1990 to 2023, Dutch blood banking data and hospital data on fetal hydrops. Using wavelet analysis, we identified annual epidemic cycles in the Netherlands in the period 1990-2019 and we identified superimposed multiannual cycles in the period 1990-2009. After 2009, no multiannual cycle could be identified, although the incidence fluctuated and correlates with number of IUT performed. As of 2020, weekly reports of B19V infection demonstrated a historically low incidence and B19V-DNA positive blood donors were nearly absent. From May 2020 to May 2023, no IUT for B19V-related hydrops was performed. In the spring of 2023, B19V infections re-emerged, reaching pre-pandemic epidemic levels. Due to the changes in B19V epidemiology over the last 30 years and the near-absence of B19V during the COVID-19 pandemic, the resulting low immunity levels may lead to rebound outbreaks. Alertness to severe complications such as fetal hydrops is warranted.

Cardiac adaptation and malformation in twin-twin transfusion syndrome and selective fetal growth restriction: A systematic review.

OBJECTIVES: This systematic review explores cardiac adaptation in monochorionic (MC) twins with twin-twin transfusion syndrome (TTTS) or selective fetal growth restriction (sFGR) and assesses the risk of congenital heart defects (CHDs). METHODS: Adhering to PRISMA guidelines, 63 studies were reviewed (49 on cardiac adaptation, 13 on CHD, one on both). A narrative synthesis of cardiac adaptation patterns was performed. Additionally, a meta-analysis compared the livebirth prevalence of CHD in TTTS and sFGR against uncomplicated MC twins. RESULTS: In TTTS recipients, cardiac function may be impaired for diastolic, systolic, as well as global functions, while in donors, cardiac function is generally preserved. In sFGR, large twins may show hypertrophic cardiomyopathy, and small twins may show impaired systolic function. Co-occurrence of TTTS and sFGR magnifies cardiac impact but is often underreported. Meta-analysis for CHD prevalence revealed a relative risk ratio of 3.5 (95% CI: 2.5-4.9) for TTTS and 2.2 (95%CI: 1.3-3.5) for sFGR compared with uncomplicated MC twins. CONCLUSIONS: This study highlights the well-documented cardiac adaptation in TTTS, contrasting with limited understanding in sFGR. Elevated CHD risks were observed in both conditions. Enhanced cardiovascular surveillance is warranted in complicated MC twin pregnancies. Future research should explore cardiac adaptation in sFGR and its long-term consequences.

Perspectives of extremely prematurely born adults on what to consider in prenatal decision-making: a qualitative focus group study.

OBJECTIVE: A shared decision-making (SDM) approach is recommended for prenatal decisions at the limit of viability, with a guiding role for parental values. People born extremely premature experience the consequences of the decision made, but information about their perspectives on prenatal decisions is lacking. Therefore, this study aims to describe their perspectives on what is important in decision-making at the limit of viability. DESIGN: Semi-structured focus group discussions were conducted, recorded and transcribed verbatim. The data were independently analysed by two researchers in Atlas.ti. RESULTS: Four focus groups were conducted in the Netherlands, with five to six participants each, born between 240/7 and 300/7 weeks gestation in the period between 1965 and 2002. Considering their personal life experiences and how their extremely premature birth affected their families, the participants reflected on decision-making at the limit of viability. Various considerations were discussed and summarised into the following themes: anticipated parental regret, the wish to look at the baby directly after birth, to give the infant a chance at survival, quality of life, long-term outcomes for the infant and the family, and religious or spiritual considerations. CONCLUSIONS: Insights into the perspectives of adults born extremely premature deepened our understanding of values considered in decision-making at the limit of viability. Results point out the need for a more individualised prediction of the prognosis and more extensive information on the lifelong impact of an extremely premature birth on both the infant and the family. This could help future parents and healthcare professionals in value-laden decision-making.

Severity of haemolytic disease of the fetus and newborn in patients with a history of intrauterine transfusions in a previous pregnancy: A nationwide retrospective cohort study.

OBJECTIVE: Pregnant women who received at least one intrauterine transfusion (IUT) for haemolytic disease of the fetus and newborn (HDFN) in the preceding pregnancy are presumed to have a high likelihood of requiring IUTs again, often starting at an earlier gestational age. Our aim was to quantify these risks in a large national cohort. DESIGN: Retrospective cohort study of a nationwide Dutch database. SETTING: The Netherlands. POPULATION: All women treated in The Netherlands with IUTs for Rhesus D (RhD)- or Kell-mediated HDFN between 1999 and 2017 and their follow-up pregnancies were included. Pregnancies with an antigen-negative fetus were excluded. METHODS: Electronic patient files were searched for the number and gestational age of each IUT, and analysed using descriptive statistics and linear regression. MAIN OUTCOME MEASURES: Percentage of women requiring one or more IUTs again in the subsequent pregnancy, and gestational age at first IUT in both pregnancies. RESULTS: Of the 321 women in our study population, 21% (69) had a subsequent ongoing pregnancy at risk. IUTs were administered in 86% (59/69) of cases. In subsequent pregnancies, the median gestational age at first IUT was 3 weeks earlier (interquartile range -6.8 to 0.4) than in the preceding pregnancy. CONCLUSIONS: Our study shows that pregnant women with a history of IUTs in the previous pregnancy are highly likely to require IUTs again, and on average 3 weeks earlier. Clinicians need to be aware of these risks and ensure timely referral, and close surveillance from early pregnancy onwards. Additionally, for women with a history of IUT and their caregivers, this information is essential to enable adequate preconception counselling.

Opportunities and Challenges of Prognostic Models for Extremely Preterm Infants.

Predicting the short- and long-term outcomes of extremely preterm infants remains a challenge. Multivariable prognostic models might be valuable tools for clinicians, parents, and policymakers for providing accurate outcome estimates. In this perspective, we discuss the opportunities and challenges of using prognostic models in extremely preterm infants at population and individual levels. At a population level, these models could support the development of guidelines for decisions about treatment limits and may support policy processes such as benchmarking and resource allocation. At an individual level, these models may enhance prenatal counselling conversations by considering multiple variables and improving transparency about expected outcomes. Furthermore, they may improve consistency in projections shared with parents. For the development of prognostic models, we discuss important considerations such as predictor and outcome measure selection, clinical impact assessment, and generalizability. Lastly, future recommendations for developing and using prognostic models are suggested. Importantly, the purpose of a prognostic model should be clearly defined, and integrating these models into prenatal counselling requires thoughtful consideration.

[Intestinal duplication cyst in children: laparoscopically assisted resection is preferred]. / Duplicatiecyste van de darm bij kinderen.

A 5-year-old boy was seen for a second opinion as he had episodes of severe abdominal pain and a variably distended abdomen. Ultrasonography showed a suspected duplication cyst of the terminal ileum. A laparoscopically assisted resection was performed. Histology confirmed the diagnosis of a duplication cyst. A few months later a 10-year-old boy presented with a history of abdominal pain, diarrhoea and vomiting. Abdominal ultrasonography showed an intussusception halfway up the transverse colon where a cyst was seen with a fluid level. The intussusception was reduced during laparoscopy and resection of the duplication cyst of the ileum was performed. Although intestinal duplication cysts are rare (prevalence 1:4500), it is important to know they exist. Laparoscopically assisted resection is an elegant way of treating duplication cysts in children.