Hyperpolarized 13C magnetic resonance imaging in neonatal hypoxic-ischemic encephalopathy: First investigations in a large animal model

Early biomarkers of cerebral damage are essential for accurate prognosis, timely intervention, and evaluation of new treatment modalities in newborn infants with hypoxia and ischemia at birth. Hyperpolarized 13C magnetic resonance imaging (MRI) is a novel method with which to quantify metabolism in vivo with unprecedented sensitivity. We aimed to investigate the applicability of hyperpolarized 13C MRI in a newborn piglet model and whether this method may identify early changes in cerebral metabolism after a standardized hypoxic-ischemic (HI) insult. Six piglets were anesthetized and subjected to a standardized HI insult. Imaging was performed prior to and 2 h after the insult on a 3-T MR scanner. For 13C studies, [1-13C]pyruvate was hyperpolarized in a commercial polarizer. Following intravenous injection, images were acquired using metabolic-specific imaging. HI resulted in a metabolic shift with a decrease in pyruvate to bicarbonate metabolism and an increase in pyruvate to lactate metabolism (lactate/bicarbonate ratio, mean [SD]; 2.28 [0.36] vs. 3.96 [0.91]). This is the first study to show that hyperpolarized 13C MRI can be used in newborn piglets and applied to evaluate early changes in cerebral metabolism after an HI insult.

Combined achondroplasia and short stature homeobox-containing (SHOX) gene deletion in a Danish infant

Short stature or shortening of the limbs can be the result of a variety of genetic variants. Achondroplasia is the most common cause of disproportionate short stature and is caused by pathogenic variants in the fibroblast growth factor receptor 3 gene (FGFR3). Short stature homeobox (SHOX) deficiency is caused by loss or defects of the SHOX gene or its enhancer region. It is associated with a spectrum of phenotypes ranging from normal stature to Léri-Weill dyschondrosteosis characterized by mesomelia and short stature or the more severe Langer mesomelic dysplasia in case of biallelic SHOX deficiency. Little is known about the interactions and phenotypic consequences of achondroplasia in combination with SHOX deficiency, as the literature on this subject is scarce, and no genetically confirmed clinical reports exist. We present the clinical findings in an infant girl with concurrent achondroplasia and SHOX deficiency. We conclude that the clinical findings in infancy are phenotypically compatible with achondroplasia, with no features of the SHOX deficiency evident. This may change over time, as some features of SHOX deficiency only become evident later in life.

Curriculum and assessment tool for less invasive surfactant administration: an international Delphi consensus study

BACKGROUND

Training and assessment of operator competence for the less invasive surfactant administration (LISA) procedure vary. This study aimed to obtain international expert consensus on LISA training (LISA curriculum (LISA-CUR)) and assessment (LISA assessment tool (LISA-AT)).

METHODS

From February to July 2022, an international three-round Delphi process gathered opinions from LISA experts (researchers, curriculum developers, and clinical educators) on a list of items to be included in a LISA-CUR and LISA-AT (Round 1). The experts rated the importance of each item (Round 2). Items supported by more than 80% consensus were included. All experts were asked to approve or reject the final LISA-CUR and LISA-AT (Round 3).

RESULTS

A total of 153 experts from 14 countries participated in Round 1, and the response rate for Rounds 2 and 3 was >80%. Round 1 identified 44 items for LISA-CUR and 22 for LISA-AT. Round 2 excluded 15 items for the LISA-CUR and 7 items for the LISA-AT. Round 3 resulted in a strong consensus (99-100%) for the final 29 items for the LISA-CUR and 15 items for the LISA-AT.

CONCLUSIONS

This Delphi process established an international consensus on a training curriculum and content evidence for the assessment of LISA competence.

IMPACT

This international consensus-based expert statement provides content on a curriculum for the less invasive surfactant administration procedure (LISA-CUR) that may be partnered with existing evidence-based strategies to optimize and standardize LISA training in the future. This international consensus-based expert statement also provides content on an assessment tool for the LISA procedure (LISA-AT) that can help to evaluate competence in LISA operators. The proposed LISA-AT enables standardized, continuous feedback and assessment until achieving proficiency.

Early changes in cerebral metabolism after perinatal hypoxia-ischemia: a study in normothermic and hypothermic piglets

Introduction

Hypoxic ischemic encephalopathy (HIE) after a perinatal insult is a dynamic process that evolves over time. Therapeutic hypothermia (TH) is standard treatment for severe to moderate HIE. There is a lack of evidence on the temporal change and interrelation of the underlying mechanisms that constitute HIE under normal and hypothermic conditions. We aimed to describe early changes in intracerebral metabolism after a hypoxic-ischemic insult in piglets treated with and without TH and in controls.

Methods

Three devices were installed into the left hemisphere of 24 piglets: a probe measuring intracranial pressure, a probe measuring blood flow and oxygen tension, and a microdialysis catheter measuring lactate, glucose, glycerol, and pyruvate. After a standardized hypoxic ischemic insult, the piglets were randomized to either TH or normothermia.

Results

Glycerol, a marker of cell lysis, increased immediately after the insult in both groups. There was a secondary increase in glycerol in normothermic piglets but not in piglets treated with TH. Intracerebral pressure, blood flow, oxygen tension, and extracellular lactate remained stable during the secondary increase in glycerol.

Conclusion

This exploratory study depicted the development of the pathophysiological mechanisms in the hours following a perinatal hypoxic-ischemic insult with and without TH and controls.

SARS-CoV-2 placentitis and severe pregnancy outcome after maternal infection: A Danish case series

INTRODUCTION

SARS-CoV-2 infection during pregnancy may cause viral inflammation of the placenta, resulting in fetal demise even without fetal or newborn infection. The impact of timing of the infection and the mechanisms that cause fetal morbidity and mortality are not well understood.

MATERIAL AND METHODS

To describe placental pathology from women with confirmed SARS-CoV-2 infection during pregnancy, a SARS-CoV-2 immunohistochemistry-positive placenta and late miscarriage, stillbirth, neonatal death, or medically indicated birth due to fetal distress.

RESULTS

The triad of trophoblastic necrosis, inflammatory intervillous infiltrates, and increased perivillous fibrinoid deposition was present in all 17 placentas; the pregnancies resulted in eight stillbirths, two late miscarriages (19 and 21 weeks' gestation), and seven liveborn children, two of which died shortly after delivery. The severity of maternal COVID-19 was not reflected by the extent of the placental lesions. In only one case, SARS-CoV-2 was detected in lung tissue samples from the fetus. The majority events (miscarriage, stillbirth, fetal distress resulting in indicated birth, or livebirth, but neonatal death) happened shortly after maternal SARS-CoV-2 infection was diagnosed. Seven of eight sequenced cases were infected with the Delta (B.1.617.2) virus strain.

CONCLUSION

We consolidate findings from previous case series describing extensive SARS-CoV-2 placentitis and placental insufficiency leading to fetal hypoxia. We found sparse evidence to support the notion that SARS-CoV-2 virus had infected the fetus or newborn.

Expectant Management or Early Ibuprofen for Patent Ductus Arteriosus

BACKGROUND

Cyclooxygenase inhibitors are commonly used in infants with patent ductus arteriosus (PDA), but the benefit of these drugs is uncertain.

METHODS

In this multicenter, noninferiority trial, we randomly assigned infants with echocardiographically confirmed PDA (diameter, >1.5 mm, with left-to-right shunting) who were extremely preterm (<28 weeks' gestational age) to receive either expectant management or early ibuprofen treatment. The composite primary outcome included necrotizing enterocolitis (Bell's stage IIa or higher), moderate to severe bronchopulmonary dysplasia, or death at 36 weeks' postmenstrual age. The noninferiority of expectant management as compared with early ibuprofen treatment was defined as an absolute risk difference with an upper boundary of the one-sided 95% confidence interval of less than 10 percentage points.

RESULTS

A total of 273 infants underwent randomization. The median gestational age was 26 weeks, and the median birth weight was 845 g. A primary-outcome event occurred in 63 of 136 infants (46.3%) in the expectant-management group and in 87 of 137 (63.5%) in the early-ibuprofen group (absolute risk difference, -17.2 percentage points; upper boundary of the one-sided 95% confidence interval [CI], -7.4; P<0.001 for noninferiority). Necrotizing enterocolitis occurred in 24 of 136 infants (17.6%) in the expectant-management group and in 21 of 137 (15.3%) in the early-ibuprofen group (absolute risk difference, 2.3 percentage points; two-sided 95% CI, -6.5 to 11.1); bronchopulmonary dysplasia occurred in 39 of 117 infants (33.3%) and in 57 of 112 (50.9%), respectively (absolute risk difference, -17.6 percentage points; two-sided 95% CI, -30.2 to -5.0). Death occurred in 19 of 136 infants (14.0%) and in 25 of 137 (18.2%), respectively (absolute risk difference, -4.3 percentage points; two-sided 95% CI, -13.0 to 4.4). Rates of other adverse outcomes were similar in the two groups.

CONCLUSIONS

Expectant management for PDA in extremely premature infants was noninferior to early ibuprofen treatment with respect to necrotizing enterocolitis, bronchopulmonary dysplasia, or death at 36 weeks' postmenstrual age. (Funded by the Netherlands Organization for Health Research and Development and the Belgian Health Care Knowledge Center; BeNeDuctus ClinicalTrials.gov number, NCT02884219; EudraCT number, 2017-001376-28.).

Epinephrine vs placebo in neonatal resuscitation: ROSC and brain MRS/MRI in term piglets

BACKGROUND

We aimed to investigate the effect of epinephrine vs placebo on return of spontaneous circulation (ROSC) and brain magnetic resonance spectroscopy and imaging (MRS/MRI) in newborn piglets with hypoxic cardiac arrest (CA).

METHODS

Twenty-five piglets underwent hypoxia induced by endotracheal tube clamping until CA. The animals were randomized to CPR + intravenous epinephrine or CPR + placebo (normal saline). The primary outcome was ROSC, and secondary outcomes included time-to-ROSC, brain MRS/MRI, and composite endpoint of death or severe brain MRS/MRI abnormality.

RESULTS

ROSC was more frequent in animals treated with epinephrine than placebo; 10/13 vs 4/12, RR = 2.31 (95% CI: 1.09-5.77). We found no difference in time-to-ROSC (120 (113-211) vs 153 (116-503) seconds, p = 0.7) or 6-h survival (7/13 vs 3/12, p = 0.2). Among survivors, there was no difference between groups in brain MRS/MRI. We found no difference in the composite endpoint of death or severe brain MRS/MRI abnormality; RR = 0.7 (95% CI: 0.37-1.19).

CONCLUSIONS

Resuscitation with epinephrine compared to placebo improved ROSC frequency after hypoxic CA in newborn piglets. We found no difference in time-to-ROSC or the composite endpoint of death or severe brain MRS/MRI abnormality.

IMPACT

In a newborn piglet model of hypoxic cardiac arrest, resuscitation with epinephrine compared to placebo improved the rate of return of spontaneous circulation and more than doubled the 6-h survival. Brain MRS/MRI biomarkers were used to evaluate the effect of epinephrine vs placebo. We found no difference between groups in the composite endpoint of death or severe brain MRS/MRI abnormality. This study adds to the limited evidence regarding the effect and safety of epinephrine; the lack of high-quality evidence from randomized clinical trials was highlighted in the latest ILCOR 2020 guidelines, and newborn animal studies were specifically requested.

No Differences in Cerebral Immunohistochemical Markers following Remote Ischemic Postconditioning in Newborn Piglets with Hypoxia-Ischemia

BACKGROUND

Despite therapeutic hypothermia, neonates with hypoxic-ischemic encephalopathy still develop neurological disabilities. We have previously investigated neuroprotection by remote ischemic postconditioning (RIPC) in newborn piglets following hypoxia-ischemia (HI). The aim of this study was to further investigate potential effects of RIPC on cerebral immunohistochemical markers related to edema, apoptosis, and angiogenesis.

METHODS

Brain expression of aquaporin 4, caspase-3, B-cell lymphoma 2, and vascular endothelial growth factor was analyzed by immunohistochemistry in 23 piglets, randomly selected from a larger study of RIPC after HI. Twenty animals were subjected to 45 minutes of HI and randomized to treatment with and without RIPC, while three animals were randomized to sham procedures. RIPC was conducted by four conditioning cycles of 5-minute ischemia and reperfusion. Piglets were euthanized 72 hours after the HI insult.

RESULTS

Piglets subjected to HI treated with and without RIPC were similar at baseline and following the HI insult. However, piglets randomized to HI alone had longer duration of low blood pressure during the insult. We found no differences in the brain expression of the immunohistochemical markers in any regions of interest or the whole brain between the two HI groups.

CONCLUSION

RIPC did not influence brain expression of markers related to edema, apoptosis, or angiogenesis in newborn piglets at 72 hours after HI. These results support previous findings of limited neuroprotective effect by this RIPC protocol. Our results may have been affected by the time of assessment, use of fentanyl as anesthetic, or limitations related to our immunohistochemical methods.

Remote ischemic postconditioning for neuroprotection after newborn hypoxia-ischemia: systematic review of preclinical studies

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) is a major contributor to death and disability worldwide. Remote ischemic postconditioning (RIPC) may offer neuroprotection but has only been tested in preclinical models. Various preclinical models with different assessments of outcomes complicate interpretation. The objective of this systematic review was to determine the neuroprotective effect of RIPC in animal models of HIE.

METHODS

The protocol was preregistered at The International Prospective Register of Systematic Reviews (PROSPERO) (CRD42020205944). Literature was searched in PubMed, Embase, and Web of Science (April 2020). A formal meta-analysis was impossible due to heterogeneity and a descriptive synthesis was performed.

RESULTS

Thirty-two papers were screened, and five papers were included in the analysis. These included three piglet studies and two rat studies. A broad range of outcome measures was assessed, with inconsistent results. RIPC improved brain lactate/N-acetylaspartate ratios in two piglet studies, suggesting a limited metabolic effect, while most other outcomes assessed were equally likely to improve or not.

CONCLUSIONS

There is a lack of evidence to evaluate the neuroprotective effect of RIPC in HIE. Additional studies should aim to standardize methodology and outcome acquisition focusing on clinically relevant outcomes. Future studies should address the optimal timing and duration of RIPC and the combination with therapeutic hypothermia.

IMPACT

This systematic review summarizes five preclinical studies that reported inconsistent effects of RIPC as a neuroprotective intervention after hypoxia-ischemia. The heterogeneity of hypoxia-ischemia animal models employed, mode of postconditioning, and diverse outcomes assessed at varying times means the key message is that no clear conclusions on effect can be drawn. This review highlights the need for future studies to be designed with standardized methodology and common clinically relevant outcomes in models with documented translatability to the human condition.

Teamwork and Adherence to Guideline on Newborn Resuscitation-Video Review of Neonatal Interdisciplinary Teams

BACKGROUND

Little is known about the importance of non-technical skills for the adherence to guidelines, when teams of midwives, obstetricians, anesthesiologists, and pediatricians resuscitate and support the transition of newborns. Non-technical skills are competences underpinning successful teamwork in healthcare. These are usually referred to as leadership, situational awareness, communication, teamwork, decision making, and coping with stress and fatigue.

OBJECTIVE

By review of videos of teams managing newborns with difficult transition, we aimed to investigate whether the level of the teams' non-technical skills was associated with the degree of adherence to guidelines for newborn resuscitation and transitional support at birth.

METHODS

Four expert raters independently assessed 43 real-life videos of teams managing newborns with transitional difficulties, two assessed the non-technical score and two assessed the clinical performance. Exposure was the non-technical score, obtained by the Global Assessment Of Team Performance checklist (GAOTP). GAOTP was rated on a Likert Scale 1-5 (1 = poor, 3 = average and 5 = excellent). The outcome was the clinical performance score of the team assessed according to adherence of the European Resuscitation Counsel (ERC) guideline for neonatal resuscitation and transitional support. The ERC guideline was adapted into the checklist TeamOBS-Newborn to facilitate a structured and simple performance assessment (low score 0-60, average 60-84, high 85-100). Interrater agreement was analyzed by intraclass correlation (ICC), Bland-Altman analysis, and Cohen's kappa weighted. The risk of high and low clinical performance was analyzed on the logit scale to meet the assumptions of normality and constant standard deviation.

RESULTS

Teams with an excellent non-technical score had a relative risk 5.5 [95% confidence interval (CI) 2.4-22.5] of high clinical performance score compared to teams with average non-technical score. In addition, we found a dose response like association. The specific non-technical skills associated with the highest degree of adherence to guidelines were leadership and teamwork, coping with stress and fatigue, and communication with parents. Inter-rater agreement was high; raters assessing non-technical skills had an interclass coefficient (ICC) 0.88 (95% CI 0.79-0.94); the neonatologists assessing clinical performance had an ICC of 0.81 (95% CI 0.66-0.89).

CONCLUSION

Teams with an excellent non-technical score had five times the chance of high clinical performance compared to teams with average non-technical skills. High performance teams were characterized by good leadership and teamwork, coping with stress, and fatigue and communication with parents.

Association of labour epidural analgesia with neurodevelopmental disorders in offspring: a Danish population-based cohort study

BACKGROUND

Whether labour epidural analgesia impacts risk of neurodevelopmental disorders in offspring is unsettled, raising public and scientific concerns. We explored the association between maternal labour epidural analgesia and autism spectrum disorder, and specific developmental disorder, attention-deficit hyperactivity disorder, intellectual disability, and epilepsy in offspring.

METHODS

This nationwide population-based cohort study included 624 952 live-born singletons delivered by women who intended to deliver vaginally (i.e. vaginal and intrapartum Caesarean deliveries) in Denmark from 2005 to 2016. A total of 80 862 siblings discordant for exposure to labour epidural analgesia were analysed in a sibling-matched analysis. Both full-cohort and sibling-matched analyses were performed to estimate hazard ratios (HRs) of offspring risk of autism spectrum disorder, specific developmental disorder, attention-deficit hyperactivity disorder, intellectual disability, and epilepsy, according to exposure to labour epidural analgesia, adjusted for maternal socio-economic, pregnancy, and perinatal covariates.

RESULTS

In the full cohort, maternal labour epidural analgesia was associated with autism spectrum disorder in offspring (HR 1.11; 95% confidence interval [CI]: 1.04-1.18); however, in the sibling-matched analysis, no association with autism spectrum disorder was found (HR 1.03; 95% CI: 0.84-1.27). The association between labour epidural analgesia and specific developmental disorder (HR 1.12; 95% CI: 1.03-1.22) in the full cohort also disappeared in the sibling-matched analysis (HR 1.01; 95% CI: 0.78-1.31). No association between maternal labour epidural analgesia and the remaining neurodevelopmental disorders was found overall (attention-deficit hyperactivity disorder, HR 0.98; 95% CI: 0.92-1.03; intellectual disability, HR 0.98; 95% CI: 0.85-1.14; epilepsy, HR 0.89; 95% CI: 0.79-1.00) or in the sibling-matched analyses.

CONCLUSIONS

Our findings did not support an association between maternal attention-deficit hyperactivity disorder and autism spectrum disorder, specific developmental disorder, attention-deficit hyperactivity disorder, intellectual disability, or epilepsy.

Neonatal jaundice and autism spectrum disorder: a systematic review and meta-analysis

BACKGROUND

Two meta-analyses concluded that jaundice was associated with an increased risk of autism. We hypothesize that these findings were due to methodological limitations of the studies included. Neonatal jaundice affects many infants and risks of later morbidity may prompt physicians towards more aggressive treatment.

METHODS

To conduct a systematic literature review and a meta-analysis of the association between neonatal jaundice and autism with particular attention given to low risk of bias studies. Pubmed, Scopus, Embase, Cochrane, and Google Scholar were searched for publications until February 2019. Data was extracted by use of pre-piloted structured sheets. Low risk of bias studies were identified through predefined criteria.

RESULTS

A total of 32 studies met the inclusion criteria. The meta-analysis of six low risk of bias studies showed no association between neonatal jaundice and autism; cohort studies risk ratio 1.09, 95% CI, 0.99-1.20, case-control studies odds ratio 1.29 95% CI 0.95, 1.76. Funnel plot of all studies suggested a high risk of publication bias.

CONCLUSIONS

We found a high risk of publication bias, selection bias, and potential confounding in all studies. Based on the low risk of bias studies there was no convincing evidence to support an association between neonatal jaundice and autism.

IMPACT

Meta-analysis of data from six low risk of bias studies indicated no association between neonatal jaundice and autism spectrum disorder. Previous studies show inconsistent results, which may be explained by unadjusted confounding and selection bias. Funnel plot suggested high risk of publication bias when including all studies. There is no evidence to suggest jaundice should be treated more aggressively to prevent autism.

Challenges in conducting paediatric trials with off-patent drugs

Introduction

For more than two decades several initiatives have emerged to increase recruitment of paediatric patients in drug trials. While trials of newly approved drugs have successfully included paediatric patients in their drug development plan, the collection of safety and efficacy data in paediatric patients treated with off-patent drugs poses a major challenge.

Aim

This paper aims to draw attention to problems and solutions across countries in investigator-initiated trials with off-patent drugs and recommendations for improvement.

Discussion

Off-patent drugs represent a particular challenge when they are included in a paediatric trial; these trials are frequently investigator-initiated and have limited resources, off-patent drugs are used in clinical settings and the trial protocol must accommodate e.g. flexible dosing and specimen sampling schedules, off-patent drugs typically exist in few formulations and concentrations which necessitates special or imported formulations. Paediatric trials are in some countries confined by e.g. consent from both parents, regardless of whether the Investigational Medicinal Product (IMP) is a well-known drug or a new experimental drug.

Conclusion

Facilitation of research in off-patent drugs can improve evidence-based and safe treatment for the paediatric population. The following supportive initiatives are recommended: Harmonised regulatory change that improves the consent process in low risk trials to prevent inadequate recruitment. Pharmaceutical expertise should be prioritized to secure the best choice of IMP and supply. Constant focus on flexibility in design to accommodate a multifaceted paediatric population and ensure that trial protocols fit in well with routine clinical care and family life.

Fertility treatment with clomiphene citrate and childhood epilepsy: a nationwide cohort study

STUDY QUESTION

Is fertility treatment with clomiphene citrate associated with an increased risk of childhood epilepsy, including specific subtypes of epilepsy?

SUMMARY ANSWER

Fertility treatment with clomiphene citrate may be associated with a small increased risk of idiopathic generalized epilepsy and focal epilepsy in childhood.

WHAT IS KNOWN ALREADY

Clomiphene citrate is among the most commonly prescribed drugs for fertility treatment. However, concerns have been raised as to whether the treatment may harm the developing fetus.

STUDY DESIGN, SIZE, DURATION

This nationwide cohort study included all pregnancies in Denmark from 1 July 1995 resulting in a live-born singleton child before 31 December 2013. The children were followed until 31 December 2016.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Children conceived after fertility treatment with clomiphene citrate were identified from the Danish National Prescription Registry. The primary outcomes were childhood epilepsy, idiopathic generalized epilepsy, and focal epilepsy identified from the Danish National Patient Register and from antiepileptic drug prescriptions in the Danish National Prescription Registry. All analyses were conducted using Cox proportional hazards regression.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 1 081 291 pregnancies were included; 12 644 children (1.2%) developed epilepsy. Fertility treatment with clomiphene citrate was associated with a small increased risk of childhood epilepsy (hazard ratio [HR]: 1.10; 95% CI: 1.00-1.22), idiopathic generalized epilepsy (HR: 1.41; 95% CI: 1.16-1.72), and focal epilepsy (HR: 1.26; 95% CI: 1.04-1.53).

LIMITATIONS, REASONS FOR CAUTION

The increased risk of idiopathic generalized epilepsy may be due to confounding from time stable parental characteristics related to treatment with clomiphene citrate, since the association was strongest with the lowest administered dosage of clomiphene citrate prior to conception, and the association disappeared in a sibling analysis.

WIDER IMPLICATIONS OF THE FINDINGS

The increased risk of focal epilepsy may be related to the hormonal treatment, since the association tended to increase with increasing cumulative dosage of clomiphene citrate prior to conception, and the association persisted in a sibling analysis. This finding may be of clinical importance, since alternative hormones are available for fertility treatment.

STUDY FUNDING/COMPETING INTEREST(S)

Financial support from Aarhus University and the Aase and Ejnar Danielsen Foundation. U.S.K. received personal teaching fees from Merck, outside the submitted work.

TRIAL REGISTRATION NUMBER

N/A.

Congenital Heart Defects and the Risk of Spontaneous Preterm Birth

OBJECTIVES

To estimate the association between major types of congenital heart defects (CHD) and spontaneous preterm birth, and to assess the potential underlying mechanisms.

STUDY DESIGN

This nationwide, registry-based study included a cohort of all singleton pregnancies in Denmark from 1997 to 2013. The association between CHD and spontaneous preterm birth was estimated by multivariable Cox regression, adjusted for potential confounders. The following potential mechanisms were examined: maternal genetics (sibling analyses), polyhydramnios, preterm prelabor rupture of membranes, preeclampsia, and indicators of fetal and placental growth.

RESULTS

The study included 1 040 474 births. Compared with the general population, CHD was associated with an increased risk of spontaneous preterm birth, adjusted hazard ratio 2.1 (95% CI, 1.9-2.4). Several subtypes were associated with increased risks, including pulmonary stenosis combined with a septal defect, 5.2 (95% CI, 3.7-7.5); pulmonary stenosis or atresia, 3.1 (95% CI, 2.4-4.1); tetralogy of Fallot 2.5 (95% CI, 1.6-3.8); coarctation or interrupted aortic arch 2.2 (95% CI, 1.5-3.2); and hypoplastic left heart syndrome, 2.0 (95% CI, 1.0-4.1). Overall, preterm prelabor rupture of membranes mediated more than one-half of the association. Maternal genetics, polyhydramnios, or indicators of fetal or placental growth did not explain the reported associations.

CONCLUSIONS

CHD, especially right ventricular outflow tract obstructions, were associated with an increased risk of spontaneous preterm birth. The risk was carried by the CHD and not by maternal genetics. Moreover, preterm prelabor rupture of membranes was identified as a potential underlying mechanism.

Short-term outcomes of remote ischemic postconditioning 1 h after perinatal hypoxia-ischemia in term piglets

BACKGROUND

We aimed to assess remote ischemic postconditioning (RIPC) as a neuroprotective strategy after perinatal hypoxia-ischemia (HI) in a piglet model.

METHODS

Fifty-four newborn piglets were subjected to global HI for 45 min. One hour after HI, piglets were randomized to four cycles of 5 min of RIPC or supportive treatment only. The primary outcome was brain lactate/N-acetylaspartate (Lac/NAA) ratios measured by magnetic resonance spectroscopy at 72 h. Secondary outcomes included diffusion-weighted imaging and neuropathology.

RESULTS

RIPC was associated with a reduction in overall and basal ganglia Lac/NAA ratios at 72 h after HI, but no effect on diffusion-weighted imaging, neuropathology scores, neurological recovery, or mortality.

CONCLUSIONS

The selective effect of RIPC on Lac/NAA ratios may suggest that the metabolic effect is greater than the structural and functional improvement at 72 h after HI. Further studies are needed to address whether there is an add-on effect of RIPC to hypothermia, together with the optimal timing, number of cycles, and duration of RIPC.

IMPACT

RIPC after HI was associated with a reduction in overall and basal ganglia Lac/NAA ratios at 72 h, but had no effect on diffusion-weighted imaging, neuropathology scores, neurological recovery, or mortality. RIPC may have a selective metabolic effect, ameliorating lactate accumulation without improving other short-term outcomes assessed at 72 h after HI. We applied four cycles of 5 min RIPC, complementing existing data on other durations of RIPC. This study adds to the limited data on RIPC after perinatal HI and highlights that knowledge gaps, including timing and duration of RIPC, must be addressed together with exploring the combined effects with hypothermia.

Cardiovascular biomarkers in the evaluation of patent ductus arteriosus in very preterm neonates: A cohort study

BACKGROUND

The evaluation of the patent ductus arteriosus (PDA) in the very premature neonate is a challenge. Echocardiography provides an interpretation of the hemodynamic condition. It is however, only a snapshot. Biomarkers may represent a physiological response to the hemodynamic alterations brought on by the PDA and may add to the identification of the clinical significant PDA.

AIM

To investigate the association between mid regional proadrenomodulin (MR-proADM), N-terminal pro b-type natriuretic peptide (NT-proBNP), mid regional pro-atrial natriuretic peptide (MR-proANP), C-terminal pro endothelin-1 (CT-proET1) and copeptin and echocardiographic measures of PDA.

STUDY DESIGN

Cohort study with echocardiography performed on day 3 and 6. Blood samples from day 3.

SUBJECT

139 consecutive neonates born at a gestational age <32 weeks.

OUTCOME MEASURES

The main outcomes were presence of a PDA day 3 and 6, PDA diameter, left atrium to aorta ratio (LA:Ao-ratio), and descending aorta diastolic flow (DADF).

RESULTS

Adjusted plasma levels of all investigated biomarkers, except CT-proET1, were found to be associated with both PDA diameter and LA:Ao-ratio, and also the presence of a large PDA. CT-proET1 and copeptin was found to be associated with abnormal DADF. Using pre-specified cut-off values NT-proBNP and MR-proANP day 3 seemed to be of value in identifying a large PDA day 3 and 6 in very preterm neonates.

CONCLUSION

Among the investigated biomarkers NT-proBNP and MR-proANP performed best in relation to echocardiographic markers of PDA severity in very preterm neonates.

No Added Neuroprotective Effect of Remote Ischemic Postconditioning and Therapeutic Hypothermia After Mild Hypoxia-Ischemia in a Piglet Model

Introduction: Hypoxic ischemic encephalopathy (HIE) is a major cause of death and disability in children worldwide. Apart from supportive care, the only established treatment for HIE is therapeutic hypothermia (TH). As TH is only partly neuroprotective, there is a need for additional therapies. Intermittent periods of limb ischemia, called remote ischemic postconditioning (RIPC), have been shown to be neuroprotective after HIE in rats and piglets. However, it is unknown whether RIPC adds to the effect of TH. We tested the neuroprotective effect of RIPC with TH compared to TH alone using magnetic resonance imaging and spectroscopy (MRI/MRS) in a piglet HIE model. Methods: Thirty-two male and female piglets were subjected to 45-min global hypoxia-ischemia (HI). Twenty-six animals were randomized to TH or RIPC plus TH; six animals received supportive care only. TH was induced through whole-body cooling. RIPC was induced 1 h after HI by four cycles of 5 min of ischemia and 5 min of reperfusion in both hind limbs. Primary outcome was Lac/NAA ratio at 24 h measured by MRS. Secondary outcomes were NAA/Cr, diffusion-weighted imaging (DWI), arterial spin labeling, aEGG score, and blood oxygen dependent (BOLD) signal measured by MRI/MRS at 6, 12, and 24 h after the hypoxic-ischemic insult. Results: All groups were subjected to a comparable but mild insult. No difference was found between the two intervention groups in Lac/NAA ratio, NAA/Cr ratio, DWI, arterial spin labeling, or BOLD signal. NAA/Cr ratio at 24 h was higher in the two intervention groups compared to supportive care only. There was no difference in aEEG score between the three groups. Conclusion: Treatment with RIPC resulted in no additional neuroprotection when combined with TH. However, insult severity was mild and only evaluated at 24 h after HI with a short MRS echo time. In future studies more subtle neurological effects may be detected with increased MRS echo time and post mortem investigations, such as brain histology. Thus, the possible neuroprotective effect of RIPC needs further evaluation.

Magnesium sulphate for fetal neuroprotection at imminent risk for preterm delivery: a systematic review with meta-analysis and trial sequential analysis

BACKGROUND

Ordinary meta-analyses indicate that magnesium sulphate (MgSO₄ ) treatment in women at imminent risk for preterm delivery decreases the offspring's risk of cerebral palsy (CP). However, repetitive testing of cumulative data calls for statistical caution, e.g. by trial sequential analysis (TSA), for which there are previously insufficient samples to draw a firm conclusion. Recently, a randomised controlled trial (RCT) provided additional data that potentially increased the sample size such that a new TSA might detect a statistically significant effect.

OBJECTIVES

To assess the possible fetal neuroprotective effect of MgSO₄ for women at imminent risk for preterm delivery in an updated systematic review with meta-analysis and TSA.

SEARCH STRATEGY

We searched MEDLINE, Embase, Cochrane and ClinicalTrials.gov on 8 October 2019. The search strategy clustered terms describing the MgSO₄ intervention and preterm delivery.

SELECTION CRITERIA

RCTs.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted the data. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using fixed-effects models. A TSA was applied to the primary outcome, CP. The quality of the evidence was assessed using GRADE. The protocol was registered in PROSPERO (registration: CRD42019151441).

MAIN RESULTS

We identified six eligible trials (5917 women). MgSO₄ intervention in women at imminent risk for preterm birth decreased the offspring's CP risk (meta-analysis RR 0.68, 95% CI 0.54-0.85; TSA RR 0.69, 95% CI 0.48-0.97).

CONCLUSIONS

This systematic review with meta-analysis and TSA shows conclusively that MgSO₄ , when given to women at imminent risk for preterm delivery, decreases the offspring's CP risk.

TWEETABLE ABSTRACT

Antenatal magnesium sulphate decreases the risk of cerebral palsy in children born preterm.

Alcohol intake during pregnancy and timing of puberty in sons and daughters: A nationwide cohort study

We explored whether maternal alcohol intake in early pregnancy is associated with pubertal timing in sons and daughters. In total, 15,819 children, born 2000-2003 within the Danish National Birth Cohort, gave half-yearly, self-reported information on pubertal development (Tanner stages, voice break, first ejaculation, menarche, acne, and axillary hair) from 11 years during 2012-2018. Information on maternal average alcohol intake in first trimester and binge drinking episodes (intake of ≥5 drinks on the same occasion) in first trimester was self-reported by mothers during pregnancy. Average alcohol intake of 5+ weekly drinks in first trimester was not associated with pubertal timing in sons (with no alcohol intake as the reference). A tendency towards earlier pubertal timing was observed in daughters (-2.0 (95 % confidence interval: -4.2, 0.3) months) when combining the estimates for all pubertal milestones. Binge drinking was not associated with pubertal timing in neither sons nor daughters.

Severity of hypoxic ischemic encephalopathy and heart rate variability in neonates: a systematic review

BACKGROUND

Several studies have investigated heart rate variability (HRV) as a biomarker for acute brain injury in hypoxic ischemic encephalopathy (HIE). However, the current evidence is heterogeneous and needs further reviewing to direct future studies. We aimed to systematically review whether HIE severity is associated with HRV.

METHODS

This systematic review was conducted according to the preferred reporting items for systematic review and meta analyses (PRISMA). We included studies comparing neonates with severe or moderate HIE with neonates with mild or no HIE with respect to different HRV measures within 7 days of birth. Article selection and quality assessment was independently performed by two reviewers. Risk of bias and strength of evidence was evaluated by the Newcastle-Ottawa scale (NOS) and the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

We screened 1187 studies. From these, four observational studies with 248 neonates were included. For all HRV measures, the strength of evidence was very low. Neonates with severe or moderate HIE showed a reduction in most HRV measures compared to neonates with mild or no HIE with a greater reduction in those with severe HIE.

CONCLUSIONS

Moderate and severe HIE was associated with a reduction in most HRV measures. Accordingly, HRV is a potential biomarker for HIE severity during the first week of life. However, the uncertainty calls for more studies.

Maternal Smoking During Pregnancy and Timing of Puberty in Sons and Daughters: A Population-Based Cohort Study

Because early puberty has been linked to diseases later in life, identification of modifiable causes of early puberty is of interest. We explored the possible associations between maternal smoking during pregnancy and pubertal development in sons and daughters. Between 2012 and 2017, 15,819 children from the Danish National Birth Cohort, born during 2000-2003, provided half-yearly information on puberty from the age of 11 years. We estimated adjusted age differences (in months) at attaining various pubertal milestones, including Tanner stages, per 10 daily cigarettes smoked in the first trimester of gestation. In sons, exposure to smoking in utero was associated with earlier genital development (Tanner 2, -1.3 months, 95% confidence interval (CI): -2.5, 0.0; Tanner 5, -3.7 months, 95% CI: -5.3, -2.0), pubic hair development (Tanner 2, -1.8 months, 95% CI: -2.9, -0.6; Tanner 5, -2.9 months, 95% CI: -4.2, -1.7), and voice break (-2.4 months, 95% CI: -3.6, -1.3). In daughters, maternal smoking was associated with earlier breast development (Tanner 2, -3.4 months, 95% CI: -5.3, -1.5; Tanner 5, -4.7 months, 95% CI: -6.5, -2.9), pubic hair development stages 3-5 (Tanner 5, -2.5 months, 95% CI: -4.1, -1.0), and menarche (-3.1 months, 95% CI: -4.0, -2.3). Fetal exposure to tobacco smoke might advance timing of puberty in boys and girls.

Directed acyclic graphs: a tool for causal studies in paediatrics

Many paediatric clinical research studies, whether observational or interventional, have as an eventual aim the identification or quantification of causal relationships. One might ask: does screen time influence childhood obesity? Could overuse of paracetamol in infancy cause wheeze? How does breastfeeding affect later cognitive outcomes? In this review, we present causal directed acyclic graphs (DAGs) to a paediatric audience. DAGs are a graphical tool which provide a way to visually represent and better understand the key concepts of exposure, outcome, causation, confounding, and bias. We use clinical examples, including those outlined above, framed in the language of DAGs, to demonstrate their potential applications. We show how DAGs can be most useful in identifying confounding and sources of bias, demonstrating inappropriate statistical adjustments for presumed biases, and understanding threats to validity in randomised controlled trials. We believe that a familiarity with DAGs, and the concepts underlying them, will be of benefit both to the researchers planning studies, and practising clinicians interpreting them.

Leisure time physical activity in 9- to 11-year-old children born moderately preterm: a cohort study

BACKGROUND

Physical activity is one of the best documented activities with impacts on health in children and adults. Children born preterm show reduced physical and psychosocial function compared to children born at term. This may influence their level of physical activity. Reports on moderately preterm children's physical activities during childhood are limited. Thus, the aim of this study was to compare the leisure time physical activity at age 9-11 years of moderately preterm children with that of children born at term.

METHODS

Data from 4941 mother-child pairs from the Aarhus Birth Cohort (1989-91) were used. The cohort gathered clinical information, including gestational age at delivery. Information about parental socio-demographic and lifestyle factors was obtained from questionnaires completed during the second trimester of pregnancy. Information about children's physical activities was reported in a 9- to 11-year follow-up questionnaire completed by parents detailing how many times per week their child participated in sports activities outside of school, hours spent per week playing outside, and hours per week engaged in sedentary activities. Data were analysed using multiple logistic regression with the lowest activity group as a reference group.

RESULTS

A total of 158 children (3.2%) were born moderately preterm, i.e., between 32 and 36 completed weeks. Children born moderately preterm participated in sports activities as often as their peers born at term; they also participated in frequent sports activities (≥ 4 times per week) as often as their peers. There were no differences in hours per week spent playing outside or in sedentary activities between the two groups.

CONCLUSIONS

Nine- to 11-year-old moderately preterm children participated in sports activities outside school to a similar extent as their peers and engaged in outdoor activities and sedentary activities for the same duration of time per week as their peers born at term.

Hypothermia at neonatal intensive care unit admission was not associated with respiratory disease or death in very preterm infants

AIM

This study investigated the association between hypothermia and respiratory distress syndrome (RDS), bronchopulmonary dysplasia (BPD) or death in very preterm infants admitted to a Danish neonatal intensive care unit (NICU).

METHODS

We studied 675 infants born at Aalborg University Hospital before 32 weeks and admitted to the NICU from April 1997 to December 2011. Hypothermia was defined as a core temperature of <36.5°C on admission. The primary outcome was severe RDS or death within the first three days of life, and the secondary outcome was BPD or death before 36 postmenstrual weeks. The multivariable logistic regression was adjusted for early-onset infection, gestational age, Apgar score, sex, treatment year and birth weight.

RESULTS

Infants with hypothermia had a twofold increase (OR) in the odds for RDS or death (2.03), but the adjusted OR was not statistically significant (1.36). They also demonstrated a twofold increase (OR) in the odds for BPD or death (2.28), but again the adjusted OR was not statistically significant (1.03).

CONCLUSION

After adjusting for confounders, we found that the association between hypothermia on admission to the NICU and RDS or death, or BPD or death was statistically insignificant.

Temporal trends of lipophilic persistent organic pollutants in serum from Danish nulliparous pregnant women 2011-2013

The use of the lipophilic persistent organic pollutants (POPs) including polychlorinated biphenyls (PCBs) and several organochlorine pesticides (OCPs) has been prohibited for more than 30 years. In this study, we present the temporal trends of the lipophilic POP serum concentrations in Danish nulliparous pregnant women between 2011 and 2013. We randomly selected 197 pregnant women (gestational age 11-13) from the Aarhus Birth Cohort. The concentrations of the lipophilic POPs in the serum samples were analyzed using gas chromatography. The concentrations were corrected for total serum lipids. The statistical analysis was performed by regression analysis with adjustment for age, BMI, gestational age at blood draw, and smoking status. The serum concentrations of PCB 118, 138, 153, 156, 170, 180, 187, and hexachlorobenzen, trans-nonachlor, β-hexachlorocyclohexane (β-HCH), and p,p'-dichlorodiphenyldichloroethylene were lower in 2013 than in 2011. However, the oxychlordane concentration was lowest in 2011. The serum levels of most lipophilic POPs followed downward trends during the study period, which was expected, as these compounds has been banned for many years. The upward trend of oxychlordane was unexpected and presumably a chance finding.

Maternal serum concentrations of perfluoroalkyl acids in five international birth cohorts

BACKGROUND

Perfluoroalkyl acids (PFAAs) are persistent and bioaccumulating compounds, which are spread all over the globe. We aimed to compare the PFAA concentrations in serum from pregnant women in five birth cohorts from four countries (Denmark, China, Norway, and Greenland).

METHODS

Serum samples were obtained from the following five birth cohorts including a total of 4718 pregnant women: the Danish National Birth Cohort (DNBC, years 1996-2002, Denmark), the Aarhus Birth Cohort (ABC, years 2008-2013, Denmark), the Shanghai Birth Cohort (SBC, years 2013-2015, China), the Northern Norway Mother-Child Contaminant Cohort (MISA, years 2007-2009, Norway), and the Greenlandic Birth Cohort (ACCEPT, years 2010-2013, Greenland). The samples were analyzed using liquid chromatography triple-quadrupole mass spectrometry. To ensure comparability, all samples except for the MISA samples were measured in the same laboratory. We adjusted the log-transformed PFAA concentrations for age and parity using analysis of covariance.

RESULTS AND DISCUSSION

The geometric mean (GM) of the summed concentrations of the seven most abundant PFAAs (∑PFAA) was 35ng/mL in the DNBC, 25 ng/mL in the SBC, 18ng/mL in the ACCEPT, 12ng/mL in the MISA cohort, and 12ng/mL in the ABC. The DNBC concentration was highest presumably because these samples were taken in earlier years (i.e. 1996-2002) than the samples from the other cohorts (i.e. 2007-2015), and at a time when the production of PFAAs were at the highest. When excluding the DNBC samples, we found that the concentrations of all the perfluorinated sulfonic acids (PFSAs) and one of the four perfluorinated carboxylic acids (PFCAs) were highest in the Greenlandic women, whereas the other three PFCAs were highest in the Chinese women.

CONCLUSION

The concentration and composition of serum PFAAs were similar for the Danish ABC women and the Norwegian MISA women but were otherwise different across the cohorts. The different exposure profiles might partly be related to differences in lifestyle and diet. As the concentrations and compositional patterns vary between the countries, we suggest that the health implications associated with high PFAA exposure might also differ between the countries.

Maternal serum concentrations of perfluoroalkyl acids in five international birth cohorts

BACKGROUND

Perfluoroalkyl acids (PFAAs) are persistent and bioaccumulating compounds, which are spread all over the globe. We aimed to compare the PFAA concentrations in serum from pregnant women in five birth cohorts from four countries (Denmark, China, Norway, and Greenland).

METHODS

Serum samples were obtained from the following five birth cohorts including a total of 4718 pregnant women: the Danish National Birth Cohort (DNBC, years 1996-2002, Denmark), the Aarhus Birth Cohort (ABC, years 2008-2013, Denmark), the Shanghai Birth Cohort (SBC, years 2013-2015, China), the Northern Norway Mother-Child Contaminant Cohort (MISA, years 2007-2009, Norway), and the Greenlandic Birth Cohort (ACCEPT, years 2010-2013, Greenland). The samples were analyzed using liquid chromatography triple-quadrupole mass spectrometry. To ensure comparability, all samples except for the MISA samples were measured in the same laboratory. We adjusted the log-transformed PFAA concentrations for age and parity using analysis of covariance.

RESULTS AND DISCUSSION

The geometric mean (GM) of the summed concentrations of the seven most abundant PFAAs (∑PFAA) was 35ng/mL in the DNBC, 25 ng/mL in the SBC, 18ng/mL in the ACCEPT, 12ng/mL in the MISA cohort, and 12ng/mL in the ABC. The DNBC concentration was highest presumably because these samples were taken in earlier years (i.e. 1996-2002) than the samples from the other cohorts (i.e. 2007-2015), and at a time when the production of PFAAs were at the highest. When excluding the DNBC samples, we found that the concentrations of all the perfluorinated sulfonic acids (PFSAs) and one of the four perfluorinated carboxylic acids (PFCAs) were highest in the Greenlandic women, whereas the other three PFCAs were highest in the Chinese women.

CONCLUSION

The concentration and composition of serum PFAAs were similar for the Danish ABC women and the Norwegian MISA women but were otherwise different across the cohorts. The different exposure profiles might partly be related to differences in lifestyle and diet. As the concentrations and compositional patterns vary between the countries, we suggest that the health implications associated with high PFAA exposure might also differ between the countries.

Congenital Heart Defects and Indices of Placental and Fetal Growth in a Nationwide Study of 924 422 Liveborn Infants

BACKGROUND

Congenital heart defects (CHDs) have been associated with placental anomalies. The nature and the consequences of this association remain poorly understood. We aimed to estimate the associations between all major subtypes of CHD and placental weight at birth, and the association between placental weight and measures of both overall and cerebral growth in fetuses with CHD, as well.

METHODS

We included all 924 422 liveborn Danish singletons, 1997 to 2011. CHD was present in 7569. We compared mean differences in placental weight z score between newborns with CHD and newborns without CHD by multivariable linear regression adjusted for potential confounders.

RESULTS

CHD was associated with a mean z score difference of -0.04 (95% confidence interval, -0.07 to -0.02). Some subtypes were associated with smaller placental size at birth: tetralogy of Fallot, -0.45 (95% confidence interval, -0.58 to -0.31); double-outlet right ventricle, -0.48 (95% confidence interval, -0.87 to -0.10); major ventricular septal defects, -0.41 (95% confidence interval, -0.52 to -0.29). Placental weight z score was associated with birth weight and head circumference z scores in all subtypes. In the 3 mentioned subtypes, the mean deviations from the population mean head circumference and birth weight z scores were reduced by up to 66% with adjustment for placental weight z score.

CONCLUSIONS

Three subtypes of CHD were associated with lower placental weight, and placental weight was associated with measures of both overall growth and cerebral growth in fetuses with all subtypes of CHD. In certain subtypes, the described deviations in fetal growth were reduced by up to two-thirds after adjustment for placental weight z score.

Parental Infertility, Fertility Treatment, and Childhood Epilepsy: A Population-Based Cohort Study

BACKGROUND

A few studies have indicated an increased risk of epilepsy in children conceived by fertility treatment possibly due to characteristics of the infertile couple rather than the treatment. We therefore aimed to investigate the association between parental infertility, fertility treatment, and epilepsy in the offspring, including the subtypes of epilepsy; idiopathic generalised epilepsy and focal epilepsy.

METHODS

This cohort included all pregnancies resulting in liveborn singletons from the Aarhus Birth Cohort, Denmark (1995-2013). Information on time to pregnancy and fertility treatment was obtained from pregnancy questionnaires in early pregnancy. Children developing epilepsy were identified from the Danish National Patient Register and the Danish National Prescription Registry until 2013. Data were analysed using Cox proportional hazards regression adjusted for potential confounders.

RESULTS

A total of 60 440 pregnancies were included, and 0.8% of the children developed epilepsy.The primary analyses showed no association between parental infertility or fertility treatment, and the overall risk of childhood epilepsy (hazard rate ratios (HRs); 95% confidence intervals (CIs): 1.08 (0.73, 1.60) and 1.04 (0.71, 1.52)). In secondary analyses, both parental infertility and fertility treatment were associated with an increased risk of idiopathic generalised epilepsy (HRs and 95% CIs: 2.25 (1.10, 4.58) and 2.45 (1.26, 4.75)). No association was seen for focal epilepsy.

CONCLUSION

Parental infertility or fertility treatment was not associated with an overall risk of childhood epilepsy. Parental infertility may be associated with an increased risk of idiopathic generalised epilepsy; a subtype of epilepsy believed to be of genetic origin.

Congenital Heart Defects and Measures of Fetal Growth in Newborns with Down Syndrome or 22q11.2 Deletion Syndrome

OBJECTIVES

To estimate the association between congenital heart defects (CHD) and indices of fetal growth in Down and 22q11.2 deletion syndromes.

STUDY DESIGN

We established 2 Danish nationwide cohorts of newborn singletons with either Down syndrome (n = 670) or 22q11.2 deletion syndrome (n = 155), born 1997-2011. In both cohorts, we analyzed the association between CHD, CHD severity, and indices of fetal growth by multivariable linear regression adjusted for potential confounders. We report mean differences in gestational age specific z-scores compared with newborns without CHD.

RESULTS

Down syndrome and 22q11.2 deletion syndrome were both associated with lower mean birth weight and head circumference z-scores. We found no association between CHD or CHD severity and indices of fetal growth. In Down syndrome, the association between any CHD and the mean difference in head circumference z-score was 0.03 (95% CI -0.12, 0.18), and the estimate regarding birth weight z-score was 0.09 (95% CI -0.08, 0.25). The corresponding estimates in 22q11.2 deletion syndrome were 0.00 (95% CI -0.33, 0.32) and -0.09 (95% CI -0.45, 0.26).

CONCLUSIONS

We found no association between CHD and fetal growth measures in newborns with Down syndrome or 22q11.2 deletion syndrome. Thus, in certain subtypes of CHD, the contribution of genetic factors to prenatal growth impairment may be more important than circulatory disturbances.

Determinants of serum levels of perfluorinated alkyl acids in Danish pregnant women

Humans are exposed to perfluorinated alkyl acids (PFAAs) from food, drinking water, air, dust, and consumer products. PFAAs are persistent and bio-accumulative. In the present study, we aimed to establish how the serum levels of PFAAs differ according to age, pre-pregnancy body mass index (BMI), previous miscarriages, educational level, country of birth, smoking, and alcohol intake. We included 1438 Danish pregnant nulliparous women from the Aarhus Birth Cohort. The women gave a blood serum sample between week 11 and 13 of pregnancy. Sixteen PFAAs were extracted from serum using solid phase extraction and analyzed by liquid chromatography/tandem mass spectrometry. Multivariable linear regression analysis was used to determine the associations between individual characteristics of the women and their levels of seven PFAAs that were detected in at least 50% of the samples. The total concentration of the PFAAs (∑PFAA) was higher in older women. On average, normal weight women had a higher ∑PFAA level than underweight, overweight, and obese women. Higher levels were also observed for women without previous miscarriages, women with a high educational level, women born in Denmark (as opposed to women born elsewhere but currently living in Denmark), non-smokers, and women who consumed alcohol before or during pregnancy. These associations were similar for all the studied PFAAs, although the levels of perfluoroundecanoic acid varied more across the categories of age, BMI, education, smoking, and alcohol consumption than any other PFAAs measured.

Time trends of perfluorinated alkyl acids in serum from Danish pregnant women 2008-2013

We aimed to estimate the levels and time trends of perfluorinated alkyl acids (PFAAs) in serum of 1533 Danish pregnant nulliparous women between 2008 and 2013. The selection criterion of only including nulliparous women was chosen to avoid confounding from parity. The serum samples were analyzed for sixteen PFAAs using solid phase extraction and liquid chromatography tandem mass spectrometry (LC-MS/MS). We investigated the time trends for seven PFAAs, which were detected in more than 50% of the samples: perfluorohexane sulfonate (PFHxS), perfluoroheptane sulfonate (PFHpS), perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnA). We found that the serum levels of all seven PFAAs decreased during the period from 2008 to 2013; on average PFHxS decreased with 7.0% per year, PFHpS with 14.8%, PFOS with 9.3%, PFOA with 9.1%, PFNA with 6.2%, PFDA with 6.3%, and PFUnA with 7.1% per year. Adjustment for maternal age, body mass index (BMI), educational level and gestational age at blood sampling did not change the time trends much. To our knowledge, we are the first to report decreasing trends of PFNA, PFDA and PFUnA since year 2000, thereby indicating that the phase-out of these compounds are beginning to show an effect on human serum levels.

Congenital Heart Defects and Indices of Fetal Cerebral Growth in a Nationwide Cohort of 924 422 Liveborn Infants

BACKGROUND

Neurodevelopmental disorders are the most common and distressful comorbidities associated with congenital heart defects (CHD). Head circumference at birth (HC), a proxy for prenatal cerebral growth, is an established risk factor for neurodevelopmental disorders.

METHODS AND RESULTS

In a nationwide cohort, we included all 924 422 liveborn Danish singletons, 1997 to 2011. CHD was present in 5519. The association between CHD and growth indices was analyzed by multivariable linear regression, adjusted for potential confounders. We report mean differences in gestational age-specific z scores in comparison with the general population. CHD was associated with lower HC z scores, -0.10 (95% confidence interval [CI], -0.13 to -0.08). Several CHD subtypes were associated with smaller HC, eg, hypoplastic left heart syndrome, -0.39 (95% CI, -0.58 to -0.21); common arterial trunk, -0.41 (95% CI, -0.74 to -0.09); and major ventricular septal defects, -0.25 (95% CI, -0.35 to -0.15). Other single-ventricle defects, transposition of the great arteries, tetralogy of Fallot, and anomalous pulmonary venous return, were also associated with smaller HC. Transposition of the great arteries was associated with smaller HC relative to birth weight, -0.26 (95% CI, -0.39 to -0.13). Major ventricular septal defects were associated with larger HC relative to birth weight. The results were consistent under various conditions, eg, when siblings of infants with CHD (n=5311) or infants with other major malformations (n=24 974) were used as the reference.

CONCLUSIONS

Several subtypes of CHD were associated with smaller HC. The associations with major ventricular septal defects, common arterial trunk, and anomalous pulmonary venous return have not previously been described. Only infants with transposition of the great arteries had smaller HC relative to birth weight.

Preconception Maternal Bereavement and Infant and Childhood Mortality: A Danish Population-Based Study

OBJECTIVES

Preconception maternal bereavement may be associated with an increased risk for infant mortality, although these previously reported findings have not been replicated. We sought to examine if the association could be replicated and explore if risk extended into childhood.

METHODS

Using a Danish population-based sample of offspring born 1979 to 2009 (N = 1,865,454), we analyzed neonatal (0-28 days), postneonatal infant (29-364 days), and early childhood (1-5 years) mortality after maternal bereavement in the preconception (6-0 months before pregnancy) and prenatal (between conception and birth) periods. Maternal bereavement was defined as death of a first-degree relative of the mother. Analyses were conducted using logistic and log-linear Poisson regressions that were adjusted for offspring, mother, and father sociodemographic and health factors.

RESULTS

We identified 6541 (0.004%) neonates, 3538 (0.002%) postneonates, and 2132 (0.001%) children between the ages of 1 and 5 years who died. After adjusting for covariates, bereavement during the preconception period was associated with increased odds of neonatal (adjusted odds ratio = 1.87, 95% confidence interval = 1.53-2.30) and postneonatal infant mortality (adjusted odds ratio = 1.52, 95% confidence interval = 1.15-2.02). Associations were timing specific (6 months before pregnancy only) and consistent across sensitivity analyses. Bereavement during the prenatal period was not consistently associated with increased risk of offspring mortality; however, this may reflect relatively low statistical power.

CONCLUSIONS

Results support and extend previous findings linking bereavement during the preconception period with increased odds of early offspring mortality. The period immediately before pregnancy may be a sensitive period with potential etiological implications and ramifications for offspring mortality.

Antibody response to influenza A(H1N1)pdm09 in vaccinated, serologically infected and unaffected pregnant women and their newborns

Objective

To evaluate the serological response in pregnant Danish women immunized during the 2009 pandemic by serologic infection or by vaccination with influenza A(H1N1) Pandemrix^® and describe levels of passively acquired maternal antibody in their offspring.

Design

Observational cohort study.

Setting

Department of Obstetrics, Aarhus University Hospital, Skejby, Denmark, October to December 2009.

Population

Pregnant women and their offspring

Methods

Serological analysis of antibodies to influenza A(H1N1)pdm09 by hemagglutination inhibition assay in 197 women and their offspring. Blood samples were collected consecutively at delivery from the mother and the umbilical cord. In a subgroup of 124 of the 197 women, an additional blood sample from gestational weeks 9–12 was available for analysis.

Main outcome measures

Seroconversion, geometric mean titer, geometric mean‐fold rise and protective antibodies.

Results

33 of the 124 subgroup women (27%) seroconverted during pregnancy, 79% after vaccination and 17% after serologic infection (p < 0.001). The geometric mean titer after delivery in non‐vaccinated, non‐serologically infected women was 17.1 (95%CI 15.7–18.6). The geometric mean titer increased significantly after serologic infection with H1N1 [76.5 (95%CI 51.3–113.9), p < 0.001] and after vaccination [589.6 (95%CI 339.3–1024.7), p < 0.001]. The geometric mean‐fold rise (mother at delivery/mother early pregnancy) was significantly higher after vaccination [2.23 (1.93–2.54)] than after serologic infection [1.73 (1.59–1.87), p = 0.013]. In newborns of vaccinated mothers, 89.5% had protective antibody levels compared with 15.8% in newborns of serologically infected mothers (p < 0.001).

Conclusions

Influenza vaccination during pregnancy confers passive immunity to the newborn.

A Piglet Model of Neonatal Hypoxic-Ischemic Encephalopathy

Birth asphyxia, which causes hypoxic-ischemic encephalopathy (HIE), accounts for 0.66 million deaths worldwide each year, about a quarter of the world's 2.9 million neonatal deaths. Animal models of HIE have contributed to the understanding of the pathophysiology in HIE, and have highlighted the dynamic process that occur in brain injury due to perinatal asphyxia. Thus, animal studies have suggested a time-window for post-insult treatment strategies. Hypothermia has been tested as a treatment for HIE in pdiglet models and subsequently proven effective in clinical trials. Variations of the model have been applied in the study of adjunctive neuroprotective methods and piglet studies of xenon and melatonin have led to clinical phase I and II trials(1,2). The piglet HIE model is further used for neonatal resuscitation- and hemodynamic studies as well as in investigations of cerebral hypoxia on a cellular level. However, it is a technically challenging model and variations in the protocol may result in either too mild or too severe brain injury. In this article, we demonstrate the technical procedures necessary for establishing a stable piglet model of neonatal HIE. First, the newborn piglet (< 24 hr old, median weight 1500 g) is anesthetized, intubated, and monitored in a setup comparable to that found in a neonatal intensive care unit. Global hypoxia-ischemia is induced by lowering the inspiratory oxygen fraction to achieve global hypoxia, ischemia through hypotension and a flat trace amplitude integrated EEG (aEEG) indicative of cerebral hypoxia. Survival is promoted by adjusting oxygenation according to the aEEG response and blood pressure. Brain injury is quantified by histopathology and magnetic resonance imaging after 72 hr.

Maternal intake of fat in pregnancy and offspring metabolic health - A prospective study with 20 years of follow-up

BACKGROUND

Maternal fat intake during pregnancy in relation to offspring metabolic outcomes has been studied primarily in animal models, yet little is known about the association in humans. The aim of this study was to examine the association of total and subtype of fat consumption in pregnancy with anthropometric measures and biomarkers of adiposity and glucose metabolism in the offspring.

METHODS

A source population was 965 Danish pregnant women recruited in 1988-1989 with offspring follow-up at 20 years. Information on fat intake was collected in the 30(th) week of gestation, and we subdivided fat according to saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fat. Offspring body mass index (BMI) and waist circumference (WC) were recorded at follow-up (n = 670-678), and biomarkers were quantified in a subset (n = 443) of participants. Multivariable linear and log-binomial regression were used to calculate effect estimates and 95% CI for a 1:1%energy substitution of carbohydrates for fat.

RESULTS

The mean (standard deviation) BMI was 22.1 (3.3) and 22.8 (2.9) kg/m(2) in female and male offspring, respectively. The median (10th to 90th percentile) of maternal fat intake was 31% of energy [23,39]. We found no overall associations for maternal fat intake with female offspring anthropometry. However, for male offspring higher intake of MUFA during pregnancy was associated with higher insulin levels at 20 years (Q4 vs. Q1: %Δ: 37, 95% CI: 1, 86) accompanied by a non-significant 3.6 (95% CI: -1.1, 8.2) cm increase in WC. High maternal total fat intake (>=35% energy) was also associated with higher BMI (0.9, 95% CI: 0.2, 1.6) and WC (4.0, 95% CI: 1.6, 2.3) among male offspring.

CONCLUSIONS

A high fat diet during pregnancy may increase adiposity in adult male offspring. We surmise that maternal MUFA intake during this time included both MUFA and trans fat misclassified as MUFA, and that the associations observed may be more reflective of the latter exposure.

Time to subsequent live birth according to mode of delivery in the first birth

OBJECTIVE

To estimate the rate and time to next live birth by mode of delivery.

DESIGN

Hospital-based cohort.

SETTING

Aarhus University Hospital (AUH), Denmark.

POPULATION

All pregnant women attending AUH were invited to enroll in the Aarhus Birth Cohort (ABC) study between 1989 and 2010 (n = 91,625).

METHODS

Women were followed from their first live birth until the subsequent live birth or until censoring due to study end using Cox regression models.

MAIN OUTCOME MEASURES

Rate and time to subsequent live birth according to mode of delivery.

RESULTS

46,162 index live births were identified, of which 22,462 (49%) had a subsequent live birth. Women with any type of caesarean had a 6% reduction in the rate of subsequent live birth (HR 0.94, 95% CI 0.89, 0.98), which remained unchanged in the analysis by type (emergency, HR 0.95, 95% CI 0.89, 1.02; elective, HR 0.91, 95% CI 0.85, 0.98) compared with women who had a spontaneous vaginal delivery (SVD). Operative vaginal delivery was associated with an 8% reduction in subsequent live birth rates (HR 0.92, 95% CI 0.86, 0.98) and vaginal delivery complicated by shoulder dystocia with a 19% reduction compared with SVD. Median time to next birth in days was shortest in women with a first caesarean (994 days, 95% CI 973, 1026) and longest in women with a vaginal delivery complicated by shoulder dystocia (1065 days, 95% CI 994, 1191). In women with planned pregnancies, the shortest median time to second birth was in women with breech vaginal deliveries (859 days, 95% CI 737, 1089) and the longest in women with vaginal deliveries complicated by shoulder dystocia (1193 days, 95% CI 1028, 1430).

CONCLUSION

The impact of mode of delivery on subsequent rate and time to next birth was minimal in this study. The greatest reduction was among women with assisted vaginal delivery complicated by shoulder dystocia. This study is strengthened by data on pregnancy planning as well as information on complications of pregnancy, delivery and neonatal morbidities, all of which may influence a woman's decision on subsequent birth.