Multicentre, randomised controlled trial of physiological-based cord clamping versus immediate cord clamping in infants with a congenital diaphragmatic hernia (PinC): statistical analysis plan.

BACKGROUND: Infants born with congenital diaphragmatic hernia (CDH) are at high risk of respiratory insufficiency and pulmonary hypertension. Routine practice includes immediate clamping of the umbilical cord and endotracheal intubation. Experimental animal studies suggest that clamping the umbilical cord guided by physiological changes and after the lungs have been aerated, named physiological-based cord clamping (PBCC), could enhance the fetal-to-neonatal transition in CDH. We describe the statistical analysis plan for the clinical trial evaluating the effects of PBCC versus immediate cord clamping on pulmonary hypertension in infants with CDH (PinC trial). DESIGN: The PinC trial is a multicentre, randomised controlled trial in infants with isolated left-sided CDH, born ≥ 35.0 weeks of gestation. The primary outcome is the incidence of pulmonary hypertension in the first 24 h after birth. Maternal outcomes include estimated maternal blood loss. Neonatal secondary outcomes include mortality before discharge, extracorporeal membrane oxygenation therapy, and number of days of mechanical ventilation. Infants are 1:1 randomised to either PBCC or immediate cord clamping using variable random permutated block sizes (4-8), stratified by treatment centre and estimated severity of pulmonary hypoplasia (i.e. mild/moderate/severe). At least 140 infants are needed to detect a relative reduction in pulmonary hypertension by one third, with 80% power and 0.05 significance level. A chi-square test will be used to evaluate the hypothesis that PBCC decreases the occurrence of pulmonary hypertension. This plan is written and submitted without knowledge of the collected data. The trial has been ethically approved. TRIAL REGISTRATION: ClinicalTrials.gov NCT04373902 (registered April 2020).

Neuropsychological outcome in survivors of congenital diaphragmatic hernia at 5 years of age, what does it tell?

Previous studies have frequently reported neurocognitive deficits in children born with congenital diaphragmatic hernia (CDH) at school age, which may contribute to academic difficulties. Yet, age at onset of these deficits is currently unknown. We evaluated neurocognitive skills with possible determinants in preschool children born with CDH. Eligible 5-year-old children born with CDH (2010-2015) who participated in our prospective structural follow-up program were included. We used the WPPSI-III to assess intelligence, subtests of the Kaufman-ABC for memory, and NEPSY-II to assess inhibition and attention. We included 63 children. Their test scores generally were within or significantly above normal range: total IQ = 103.4 (15.7) (p = 0.13); Verbal memory = 10.2 (2.8) (p = 0.61); Visuospatial memory = 11.4 (2.6) (p < 0.01); Inhibition = 10.5 (2.2), (p = 0.10). In univariable analyses, length of ICU-stay was negatively associated with IQ, and maximum vasoactive inotropic score and open repair were negatively associated with inhibition skills. In multivariable regression analysis, the latter association remained (B = 5.52, p = 0.04 (CI 0.32-10.72)).   Conclusions: In these tested 5-year-old children born with CDH, neuropsychological outcome was normal on average. While problems in 8-year-olds are common, we did not detect onset of these problems at age 5. Yet, we cannot rule out that this cohort had a relatively mild level of disease severity; therefore, conclusions should be interpreted with caution. However, given the growing-into-deficit hypothesis, meaning that deviant brain development in early life is revealed once higher cognitive brain functions are demanded, follow-up should be conducted up to school age, and preferably beyond. What is Known: • Children born with CDH are at risk for academic difficulties at school age. • Whether these difficulties can be detected already before school age is unknown. What is New: • At age 5 years, intelligence, inhibition, attention, and memory skills were all within normal range, or even above, in children with CDH. This is supportive of the growing-into-deficit hypothesis in this patient population. • Those who underwent open surgical correction had poorer inhibition skills than those who were corrected with minimal access surgery.

Unraveling the Genetics of Congenital Diaphragmatic Hernia: An Ongoing Challenge.

Congenital diaphragmatic hernia (CDH) is a congenital structural anomaly in which the diaphragm has not developed properly. It may occur either as an isolated anomaly or with additional anomalies. It is thought to be a multifactorial disease in which genetic factors could either substantially contribute to or directly result in the developmental defect. Patients with aneuploidies, pathogenic variants or de novo Copy Number Variations (CNVs) impacting specific genes and loci develop CDH typically in the form of a monogenetic syndrome. These patients often have other associated anatomical malformations. In patients without a known monogenetic syndrome, an increased genetic burden of de novo coding variants contributes to disease development. In early years, genetic evaluation was based on karyotyping and SNP-array. Today, genomes are commonly analyzed with next generation sequencing (NGS) based approaches. While more potential pathogenic variants are being detected, analysis of the data presents a bottleneck-largely due to the lack of full appreciation of the functional consequence and/or relevance of the detected variant. The exact heritability of CDH is still unknown. Damaging de novo alterations are associated with the more severe and complex phenotypes and worse clinical outcome. Phenotypic, genetic-and likely mechanistic-variability hampers individual patient diagnosis, short and long-term morbidity prediction and subsequent care strategies. Detailed phenotyping, clinical follow-up at regular intervals and detailed registries are needed to find associations between long-term morbidity, genetic alterations, and clinical parameters. Since CDH is a relatively rare disorder with only a few recurrent changes large cohorts of patients are needed to identify genetic associations. Retrospective whole genome sequencing of historical patient cohorts using will yield valuable data from which today's patients and parents will profit Trio whole genome sequencing has an excellent potential for future re-analysis and data-sharing increasing the chance to provide a genetic diagnosis and predict clinical prognosis. In this review, we explore the pitfalls and challenges in the analysis and interpretation of genetic information, present what is currently known and what still needs further study, and propose strategies to reap the benefits of genetic screening.