Ongoing exposure to endocrine disrupting phthalates and alternative plasticizers in neonatal intensive care unit patients.

Due to endocrine disrupting effects, di-(2-ethylhexyl) phthalate (DEHP), a plasticizer used to soften plastic medical devices, was restricted in the EU Medical Devices Regulation (EU MDR 2017/745) and gradually replaced by alternative plasticizers. Neonates hospitalized in the neonatal intensive care unit (NICU) are vulnerable to toxic effects of plasticizers. From June 2020 to August 2022, urine samples (n = 1070) were repeatedly collected from premature neonates (n = 132, 4-10 samples per patient) born at <31 weeks gestational age and/or <1500 g birth weight in the Antwerp University Hospital, Belgium. Term control neonates (n = 21, 1 sample per patient) were included from the maternity ward. Phthalate and alternative plasticizers' metabolites were analyzed using liquid-chromatography coupled to tandem mass spectrometry. Phthalate metabolites were detected in almost all urine samples. Metabolites of alternative plasticizers, di-(2-ethylhexyl)-adipate (DEHA), di-(2-ethylhexyl)-terephthalate (DEHT) and cyclohexane-1,2-dicarboxylic-di-isononyl-ester (DINCH), had detection frequencies ranging 30-95 %. Urinary phthalate metabolite concentrations were significantly higher in premature compared to control neonates (p = 0.023). NICU exposure to respiratory support devices and blood products showed increased phthalate metabolite concentrations (p < 0.001). Phthalate exposure increased from birth until four weeks postnatally. The estimated phthalate intake exceeded animal-derived no-effect-levels (DNEL) in 10 % of samples, with maximum values reaching 24 times the DNEL. 29 % of premature neonates had at least once an estimated phthalate intake above the DNEL. Preterm neonates are still exposed to phthalates during NICU stay, despite the EU Medical Devices Regulation. NICU exposure to alternative plasticizers is increasing, though currently not regulated, with insufficient knowledge on their hazard profile.

Clinical Decision Support for Improved Neonatal Care: The Development of a Machine Learning Model for the Prediction of Late-onset Sepsis and Necrotizing Enterocolitis.

OBJECTIVE: To develop an artificial intelligence-based software system for predicting late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) in infants admitted to the neonatal intensive care unit (NICU). STUDY DESIGN: Single-center, retrospective cohort study, conducted in the NICU of the Antwerp University Hospital. Continuous monitoring data of 865 preterm infants born at <32 weeks gestational age, admitted to the NICU in the first week of life, were used to train an XGBoost machine learning (ML) algorithm for LOS and NEC prediction in a cross-validated setup. Afterward, the model's performance was assessed on an independent test set of 148 patients (internal validation). RESULTS: The ML model delivered hourly risk predictions with an overall sensitivity of 69% (142/206) for all LOS/NEC episodes and 81% (67/83) for severe LOS/NEC episodes. The model showed a median time gain of ≤10 hours (IQR, 3.1-21.0 hours), compared with historical clinical diagnosis. On the complete retrospective dataset, the ML model made 721 069 predictions, of which 9805 (1.3%) depicted a LOS/NEC probability of ≥0.15, resulting in a total alarm rate of <1 patient alarm-day per week. The model reached a similar performance on the internal validation set. CONCLUSIONS: Artificial intelligence technology can assist clinicians in the early detection of LOS and NEC in the NICU, which potentially can result in clinical and socioeconomic benefits. Additional studies are required to quantify further the effect of combining artificial and human intelligence on patient outcomes in the NICU.

Hair as an alternative matrix to assess exposure of premature neonates to phthalate and alternative plasticizers in the neonatal intensive care unit.

Due to adverse health effects, di-(2-ethylhexyl) phthalate (DEHP), a plasticizer used to soften plastic medical devices (PMDs), was restricted, and gradually replaced by alternative plasticizers (APs). Up to this date, urine was the sole matrix studied for plasticizer exposure in neonates hospitalized in the neonatal intensive care unit (NICU), a population highly vulnerable to toxic effects of plasticizers. The primary aim of this study was to assess simultaneous measurement of phthalate and AP metabolites in neonatal scalp hair. In addition, we aimed to use this matrix to investigate exposure of premature neonates to plasticizers during their stay in the NICU. Hair samples in this study were collected from premature neonates and their mothers included in a prospective birth cohort study in a tertiary NICU at the Antwerp University Hospital (UZA), Belgium. Samples from premature neonates (n = 45) and their mothers (n = 107) as well as from control neonates (n = 24) and mothers (n = 29) were analyzed using liquid-chromatography coupled to tandem mass spectrometry. This is the first study reporting metabolites of phthalate and alternative plasticizers in neonatal hair samples as biomarkers for exposure to these plasticizers. Results showed that hair sampled from premature neonates after a NICU stay contained significantly higher metabolite concentrations of both phthalates (DEHP, DiBP, and DnBP; 9.0-2500, 9.3-2200, and 24.7-5300 ng/g), and alternative plasticizers (DEHA, DEHT, and TOTM; 38.8-3400, 127.5-5700, and 10.8-8700 ng/g) - when compared to healthy control neonates. Besides, DEHP and DEHT metabolite concentrations were significantly higher than in hair sampled from adult populations. In addition, prolonged NICU exposure to non-invasive respiratory support devices and gastric tubes was correlated with increased concentrations in hair samples, indicating accumulation of plasticizers in this alternative matrix. In conclusion, our data indicate that preterm neonates are still highly exposed to phthalate and alternative plasticizers during NICU stay, despite the EU Medical Devices Regulation.

Development of a neonatal Göttingen Minipig model for dose precision in perinatal asphyxia: technical opportunities, challenges, and potential further steps.

Animal models provide useful information on mechanisms in human disease conditions, but also on exploring (patho)physiological factors affecting pharmacokinetics, safety, and efficacy of drugs in development. Also, in pediatric patients, nonclinical data can be critical for better understanding the disease conditions and developing new drug therapies in this age category. For perinatal asphyxia (PA), a condition defined by oxygen deprivation in the perinatal period and possibly resulting in hypoxic ischemic encephalopathy (HIE) or even death, therapeutic hypothermia (TH) together with symptomatic drug therapy, is the standard approach to reduce death and permanent brain damage in these patients. The impact of the systemic hypoxia during PA and/or TH on drug disposition is largely unknown and an animal model can provide useful information on these covariates that cannot be assessed separately in patients. The conventional pig is proven to be a good translational model for PA, but pharmaceutical companies do not use it to develop new drug therapies. As the Göttingen Minipig is the commonly used pig strain in nonclinical drug development, the aim of this project was to develop this animal model for dose precision in PA. This experiment consisted of the instrumentation of 24 healthy male Göttingen Minipigs, within 24 h of partus, weighing approximately 600 g, to allow the mechanical ventilation and the multiple vascular catheters inserted for maintenance infusion, drug administration and blood sampling. After premedication and induction of anesthesia, an experimental protocol of hypoxia was performed, by decreasing the inspiratory oxygen fraction (FiO2) at 15%, using nitrogen gas. Blood gas analysis was used as an essential tool to evaluate oxygenation and to determine the duration of the systemic hypoxic insult to approximately 1 h. The human clinical situation was mimicked for the first 24 h after birth in case of PA, by administering four compounds (midazolam, phenobarbital, topiramate and fentanyl), frequently used in a neonatal intensive care unit (NICU). This project aimed to develop the first neonatal Göttingen Minipig model for dose precision in PA, allowing to separately study the effect of systemic hypoxia versus TH on drug disposition. Furthermore, this study showed that several techniques that were thought to be challenging or even impossible in these very small animals, such as endotracheal intubation and catheterization of several veins, are feasible by trained personnel. This is relevant information for laboratories using the neonatal Göttingen Minipig for other disease conditions or drug safety testing.

Neonatal exposure to phthalate and alternative plasticizers via parenteral nutrition.

Di-(2-ethylhexyl) phthalate (DEHP), a plasticizer used to soften plastic medical devices (PMDs), was restricted in PMDs due to adverse health effects, being gradually replaced by alternative plasticizers (APs). Parenteral nutrition (PN), essential in the care for premature neonates in the neonatal intensive care unit, is stored in plastic storage bags and administered intravenously through plastic infusion circuits. We investigated to which extent PN contributes to current phthalate and AP exposure in premature neonates. First, we showed that DEHP and several APs are present in relevant amounts in PMDs used for neonatal PN administration. Secondly, ex vivo experiments mimicking clinical PN administration showed that lipid emulsions contained significant concentrations of DEHP and several APs (ATBC, TOTM, DEHT & DEHA), while hardly any plasticizers were detected in non-lipid solutions. ATBC leached from infusion circuits, while lipid emulsions were the major source for DEHP, TOTM, DEHT, and DEHA. PN administration resulted in estimated daily exposures of 13.9 µg/kg/d DEHP and 95.7 µg/kg/d ATBC in premature neonates, below their respective reference doses. Our data indicate that premature neonates requiring PN are still exposed to DEHP, as well as to a range of APs, making it a target for reduction of harmful plasticizer exposure.

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.).

Multi-centre, randomised non-inferiority trial of early treatment versus expectant management of patent ductus arteriosus in preterm infants (the BeNeDuctus trial): statistical analysis plan.

BACKGROUND: Controversy exists about the optimal management of a patent ductus arteriosus (PDA) in preterm infants. A persistent PDA is associated with neonatal mortality and morbidity, but causality remains unproven. Although both pharmacological and/or surgical treatment are effective in PDA closure, this has not resulted in an improved neonatal outcome. In most preterm infants, a PDA will eventually close spontaneously, hence PDA treatment potentially increases the risk of iatrogenic adverse effects. Therefore, expectant management is gaining interest, even in the absence of convincing evidence to support this strategy. METHODS/DESIGN: The BeNeDuctus trial is a multicentre, randomised, non-inferiority trial assessing early pharmacological treatment (24-72 h postnatal age) with ibuprofen versus expectant management of PDA in preterm infants in Europe. Preterm infants with a gestational age of less than 28 weeks and an echocardiographic-confirmed PDA with a transductal diameter of > 1.5 mm are randomly allocated to early pharmacological treatment with ibuprofen or expectant management after parental informed consent. The primary outcome measure is the composite outcome of mortality, and/or necrotizing enterocolitis Bell stage ≥ IIa, and/or bronchopulmonary dysplasia, all established at a postmenstrual age of 36 weeks. Secondary short-term outcomes are comorbidity and adverse events assessed during hospitalization and long-term neurodevelopmental outcome assessed at a corrected age of 2 years. This statistical analysis plan focusses on the short-term outcome and is written and submitted without knowledge of the data. TRIAL REGISTRATION: ClinicalTrials.gov NTR5479. Registered on October 19, 2015, with the Dutch Trial Registry, sponsored by the United States National Library of Medicine Clinicaltrials.gov NCT02884219 (registered May 2016) and the European Clinical Trials Database EudraCT 2017-001376-28.

Functional respiratory imaging provides novel insights into the long-term respiratory sequelae of bronchopulmonary dysplasia.

RATIONALE: Bronchopulmonary dysplasia (BPD) is a common complication of preterm birth. Lung function and imaging are classically used to assess BPD. Functional respiratory imaging (FRI) combines a structural and functional assessment of the airways and their vasculature. We aimed to assess BPD using FRI and to correlate these findings with the clinical presentation. METHODS: We included 37 adolescents with a history of preterm birth (22 BPD cases and 15 preterm controls). The study protocol included a detailed history, lung function testing and computed tomography (CT) (at total lung capacity (TLC) and functional residual capacity (FRC)) with FRI. CT images were also assessed using the Aukland scoring system. RESULTS: BPD patients had lower forced expiratory volume in 1 s to forced vital capacity ratio (p=0.02) and impaired diffusion capacity (p=0.02). Aukland CT scores were not different between the two groups. FRI analysis showed higher lobar volumes in BPD patients at FRC (p<0.01), but not at TLC. Airway resistance was significantly higher in the BPD group, especially in the distal airways. Additionally, FRI showed more air trapping in BPD patients, in contrast to findings on conventional CT images. CONCLUSION: This study is the first to use FRI in research for BPD. FRI analysis showed higher lobar volumes in BPD patients, indicating air trapping and reduced inspiratory capacity. In contrast to Aukland CT scores, FRI showed more air trapping in the BPD group, suggesting that FRI might be a more sensitive detection method. Importantly, we also showed increased distal airway resistance in BPD patients. By combining structural and functional assessment, FRI may help to better understand the long-term sequelae of BPD.

Machine Learning to Support Hemodynamic Intervention in the Neonatal Intensive Care Unit.

Hemodynamic support in neonatal intensive care is directed at maintaining cardiovascular wellbeing. At present, monitoring of vital signs plays an essential role in augmenting care in a reactive manner. By applying machine learning techniques, a model can be trained to learn patterns in time series data, allowing the detection of adverse outcomes before they become clinically apparent. In this review we provide an overview of the different machine learning techniques that have been used to develop models in hemodynamic care for newborn infants. We focus on their potential benefits, research pitfalls, and challenges related to their implementation in clinical care.

The Neonatal and Juvenile Pig in Pediatric Drug Discovery and Development.

Pharmacotherapy in pediatric patients is challenging in view of the maturation of organ systems and processes that affect pharmacokinetics and pharmacodynamics. Especially for the youngest age groups and for pediatric-only indications, neonatal and juvenile animal models can be useful to assess drug safety and to better understand the mechanisms of diseases or conditions. In this respect, the use of neonatal and juvenile pigs in the field of pediatric drug discovery and development is promising, although still limited at this point. This review summarizes the comparative postnatal development of pigs and humans and discusses the advantages of the juvenile pig in view of developmental pharmacology, pediatric diseases, drug discovery and drug safety testing. Furthermore, limitations and unexplored aspects of this large animal model are covered. At this point in time, the potential of the neonatal and juvenile pig as nonclinical safety models for pediatric drug development is underexplored.

Amnioinfusion Compared With No Intervention in Women With Second-Trimester Rupture of Membranes: A Randomized Controlled Trial.

OBJECTIVE: To assess the effectiveness of amnioinfusion in women with second-trimester preterm prelabor rupture of membranes. METHODS: We performed a nationwide, multicenter, open-label, randomized controlled trial, the PPROM: Expectant Management versus Induction of Labor-III (PPROMEXIL-III) trial, in women with singleton pregnancies and preterm prelabor rupture of membranes at 16 0/7 to 24 0/7 weeks of gestation with oligohydramnios (single deepest pocket less than 20 mm). Participants were allocated to transabdominal amnioinfusion or no intervention in a one-to-one ratio by a web-based system. If the single deepest pocket was less than 20 mm on follow-up visits, amnioinfusion was repeated weekly until 28 0/7 weeks of gestation. The primary outcome was perinatal mortality. We needed 56 women to show a reduction in perinatal mortality from 70% to 35% (ß error 0.20, two-sided α error 0.05). RESULTS: Between June 15, 2012, and January 13, 2016, we randomized 28 women to amnioinfusion and 28 to no intervention. One woman was enrolled before the trial registration date (June 19, 2012). Perinatal mortality rates were 18 of 28 (64%) in the amnioinfusion group vs 21 of 28 (75%) in the no intervention group (relative risk 0.86, 95% CI 0.60-1.22, P=.39). CONCLUSION: In women with second-trimester preterm prelabor rupture of membranes and oligohydramnios, we found no reduction in perinatal mortality after amnioinfusion. CLINICAL TRIAL REGISTRATION: NTR Dutch Trial Register, NTR3492.

External Validation Study of First Trimester Obstetric Prediction Models (Expect Study I): Research Protocol and Population Characteristics.

BACKGROUND: A number of first-trimester prediction models addressing important obstetric outcomes have been published. However, most models have not been externally validated. External validation is essential before implementing a prediction model in clinical practice. OBJECTIVE: The objective of this paper is to describe the design of a study to externally validate existing first trimester obstetric prediction models, based upon maternal characteristics and standard measurements (eg, blood pressure), for the risk of pre-eclampsia (PE), gestational diabetes mellitus (GDM), spontaneous preterm birth (PTB), small-for-gestational-age (SGA) infants, and large-for-gestational-age (LGA) infants among Dutch pregnant women (Expect Study I). The results of a pilot study on the feasibility and acceptability of the recruitment process and the comprehensibility of the Pregnancy Questionnaire 1 are also reported. METHODS: A multicenter prospective cohort study was performed in The Netherlands between July 1, 2013 and December 31, 2015. First trimester obstetric prediction models were systematically selected from the literature. Predictor variables were measured by the Web-based Pregnancy Questionnaire 1 and pregnancy outcomes were established using the Postpartum Questionnaire 1 and medical records. Information about maternal health-related quality of life, costs, and satisfaction with Dutch obstetric care was collected from a subsample of women. A pilot study was carried out before the official start of inclusion. External validity of the models will be evaluated by assessing discrimination and calibration. RESULTS: Based on the pilot study, minor improvements were made to the recruitment process and online Pregnancy Questionnaire 1. The validation cohort consists of 2614 women. Data analysis of the external validation study is in progress. CONCLUSIONS: This study will offer insight into the generalizability of existing, non-invasive first trimester prediction models for various obstetric outcomes in a Dutch obstetric population. An impact study for the evaluation of the best obstetric prediction models in the Dutch setting with respect to their effect on clinical outcomes, costs, and quality of life-Expect Study II-is being planned. TRIAL REGISTRATION: Netherlands Trial Registry (NTR): NTR4143; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4143 (Archived by WebCite at http://www.webcitation.org/6t8ijtpd9).

Growth and endothelial function in the first 2 years of life.

OBJECTIVE: To test the hypothesis that the inverse association between infant growth and endothelial function at 6 months would persist to 24 months and that accelerated growth would lead to an increased percent body fat, which would, in turn, impact negatively on endothelial function. STUDY DESIGN: In a prospective observational study, 104 healthy term newborns underwent anthropometry and measurements of vascular vasodilation at 0, 6, 12, and 24 months. We recorded maximum vasodilation in response to acetylcholine (endothelium-dependent) and nitroprusside (endothelium-independent) by use of laser-Doppler vascular perfusion monitoring of the forearm skin vasculature. Additional anthropometry at 1 and 3 months was collected from child welfare centers. The data were analyzed by multilevel linear regression. RESULTS: Weight gain from 0-1 month was associated inversely with maximum perfusion in response to acetylcholine at the age of 2 years (b = -8.28 perfusion units [PU] per Δ z-score, P = .03). Weight gain from 0-1 month was related positively to maximum perfusion in response to nitroprusside (b = 10.12 PU per Δ z-score, P = .04), as was birth weight (b = 8.02 PU per z-score, P = .02). Body fat percentage did not have a significant effect in any of the perfusion models and was not related to maximum perfusion at 2 years. CONCLUSION: Infant weight gain from 0-1 month is inversely related to endothelial function in healthy term infants, at least to the age of 2 years. This relationship was not explained by an increased percentage body fat.

Can neonatal sepsis be predicted in late preterm premature rupture of membranes? Development of a prediction model.

OBJECTIVE: Women with late preterm premature rupture of membranes (PROM) have an increased risk that their child will develop neonatal sepsis. We evaluated whether neonatal sepsis can be predicted from antepartum parameters in these women. STUDY DESIGN: We used multivariable logistic regression to develop a prediction model. Data were obtained from two recent randomized controlled trials on induction of labor versus expectant management in late preterm PROM (PPROMEXIL trials, (ISRCTN29313500 and ISRCTN05689407). Data from randomized as well as non-randomized women, who consented to the use of their medical data, were used. We evaluated 13 potential antepartum predictors for neonatal sepsis. Missing data were imputed. Discriminative ability of the model was expressed as the area under the receiver operating characteristic (ROC) curve and a calibration with both a calibration plot and the Hosmer and Lemeshow goodness-of-fit test. Overall performance of the prediction model was quantified as the scaled Brier score. RESULTS: We studied 970 women. Thirty-three (3.4%) neonates suffered neonatal sepsis. Maternal age (OR 1.09 per year), maternal CRP level (OR 1.01 per mmol/l), maternal temperature (OR 1.80 per °C) and positive GBS culture (OR 2.20) were associated with an increased risk of neonatal sepsis. The model had an area under the ROC-curve of 0.71. The model had both a good calibration and accuracy. CONCLUSIONS: Antepartum parameters aid in the more precise prediction of the risk of neonatal sepsis in women with late preterm PPROM.

Economic analysis comparing induction of labor and expectant management in women with preterm prelabor rupture of membranes between 34 and 37 weeks (PPROMEXIL trial).

OBJECTIVE: To compare the costs of induction of labor and expectant management in women with preterm prelabor rupture of membranes (PPROM). DESIGN: Economic analysis based on a randomized clinical trial. SETTING: Obstetric departments of eight academic and 52 non-academic hospitals in the Netherlands. POPULATION: Women with PPROM near term who were not in labor 24 h after PPROM. METHODS: A cost-minimization analysis was done from a health care provider perspective, using a bottom-up approach to estimate resource utilization, valued with unit-costs reflecting actual costs. MAIN OUTCOME MEASURES: Primary health outcome was the incidence of neonatal sepsis. Direct medical costs were estimated from start of randomization to hospital discharge of mother and child. RESULTS: Induction of labor did not significantly reduce the probability of neonatal sepsis [2.6% vs. 4.1%, relative risk 0.64 (95% confidence interval 0.25-1.6)]. Mean costs per woman were €8094 for induction and €7340 for expectant management (difference €754; 95% confidence interval -335 to 1802). This difference predominantly originated in the postpartum period, where the mean costs were €5669 for induction vs. €4801 for expectant management. Delivery costs were higher in women allocated to induction than in women allocated to expectant management (€1777 vs. €1153 per woman). Antepartum costs in the expectant management group were higher because of longer antepartum maternal stays in hospital. CONCLUSIONS: In women with pregnancies complicated by PPROM near term, induction of labor does not reduce neonatal sepsis, whereas costs associated with this strategy are probably higher.

Genetic, maternal and placental factors in the association between birth weight and physical fitness: a longitudinal twin study.

BACKGROUND: Adult cardiorespiratory fitness and muscle strength are related to all-cause and cardiovascular mortality. Both are possibly related to birth weight, but it is unclear what the importance is of genetic, maternal and placental factors in these associations. DESIGN: Peak oxygen uptake and measures of strength, flexibility and balance were obtained yearly during adolescence (10-18 years) in 114 twin pairs in the Leuven Longitudinal Twin Study. Their birth weights had been collected prospectively within the East Flanders Prospective Twin Survey. RESULTS: We identified linear associations between birth weight and adolescent vertical jump (b = 1.96 cm per kg birth weight, P = 0.02), arm pull (b = 1.85 kg per kg birth weight P = 0.03) and flamingo balance (b = -1.82 attempts to stand one minute per kg birth weight, P = 0.03). Maximum oxygen uptake appeared to have a U-shaped association with birth weight (the smallest and largest children had the lowest uptake, P = 0.01), but this association was no longer significant after adjustment for parental BMI. Using the individual twin's deviation from his own twin pair's average birth weight, we found positive associations between birth weight and adolescent vertical jump (b = 3.49, P = 0.0007) and arm pull (b = 3.44, P = 0.02). Δ scores were calculated within the twin pairs as first born twin minus second born twin. Δ birth weight was associated with Δ vertical jump within MZ twin pairs only (b = 2.63, P = 0.009), which indicates importance of placental factors. CONCLUSIONS: We found evidence for an association between adolescent physical performance (strength, balance and possibly peak oxygen uptake) and birth weight. The associations with vertical jump and arm pull were likely based on individual, more specifically placental (in the case of vertical jump) factors. Our results should be viewed as hypothesis-generating and need confirmation, but potentially support preventive strategies to optimize birth weight, for example via placental function, to target later fitness and health.

Genetic and environmental factors in associations between infant growth and adult cardiometabolic risk profile in twins.

BACKGROUND: Accelerated infant growth is associated with an altered, mostly adverse adult cardiometabolic risk profile. The importance of genetic and environmental factors to these associations is unclear. OBJECTIVE: The objective was to examine the importance of genetic and environmental factors in the associations between infant growth and adult cardiometabolic risk factors (anthropometric characteristics, lipids, insulin sensitivity, leptin, blood pressure, and fibrinogen) in twins. DESIGN: Cardiometabolic risk factors were assessed in 240 twin pairs (aged 18-34 y) from the East Flanders Prospective Twin Survey. Infant growth was defined as change in weight z score. We regressed intrapair differences in growth during 4 growth windows (0-1, 1-6, 6-12, and 12-24 mo) against intrapair differences in the risk factors in monozygotic and dizygotic twins separately. RESULTS: Within monozygotic twin pairs only, associations between infant growth and most adult lipids, glucose, leptin, and blood pressure (eg, systolic blood pressure: b = 5.95 mm Hg per change in z score, P = 0.01 in monozygotic twins; b = -1.64, P = 0.82 in dizygotic twins from 12 to 24 mo) were found. Within dizygotic twin pairs only, associations between growth and triglycerides and fibrinogen (eg, fibrinogen: b = 0.07 ln mg/dL per change in z score, P = 0.31 in monozygotic twins; b = 0.79, P = 0.01 in dizygotic twins from 0 to 1 mo) were identified. Most associations showed a detrimental effect of accelerated growth, but beneficial associations were also identified (eg, total-to-high-density-lipoprotein cholesterol ratio: b = -0.22 per change in z score from 1 to 6 mo, P = 0.008 in monozygotic twins). CONCLUSION: Our data showed that environmental factors play a role in the associations between infant growth and most adult lipids, glucose, leptin, and blood pressure, whereas genetic factors are involved regarding triglycerides and fibrinogen.

Influence of growth during infancy on endothelium-dependent vasodilatation at the age of 6 months.

Low birth weight and accelerated infant growth are associated with cardiovascular disease in adulthood. Endothelial dysfunction is regarded as a precursor of atherosclerosis and is also related to infant growth. We aimed to examine whether an association between infant growth and endothelial function is already present during discrete periods of growth during the first 6 months of life in healthy term infants. A cohort of 104 newborns was studied in the first week after birth and reexamined at the age of 6 months. Maximum vasodilatation in response to acetylcholine (endothelium dependent) and nitroprusside (endothelium independent) was measured in the vasculature of the forearm skin, using laser Doppler flowmetry and iontophoresis. Growth was calculated as difference in Z scores for weight, length, weight-for-length, and head circumference. Multivariable multilevel linear regression was used for the analysis. Growth from 0 to 1 month (calculated as difference in weight) was the only window in the first 6 months of life that was significantly and inversely associated with endothelium-dependent vasodilatation at 6 months (b=-11.72 perfusion units per Z score, P=0.01 in multivariable analysis). Birth size was not important when considered simultaneously with infant growth. Maximum endothelium-independent vasodilatation was not associated with birth size or growth parameters. We conclude that growth in the first month of life is inversely associated with endothelium-dependent vasodilatation at the age of 6 months in healthy term infants, regardless of birth size.

Management of late-preterm premature rupture of membranes: the PPROMEXIL-2 trial.

OBJECTIVE: The evidence for the management of near term prelabor rupture of membranes is poor. From January 2007 until September 2009, we performed the PPROM Expectant Management versus Induction of Labor (PPROMEXIL) trial. In this trial, we showed that in women with preterm prelabor rupture of membranes (PPROM), the incidence of neonatal sepsis was low, and the induction of labor (IoL) did not reduce this risk. Because the PPROMEXIL trial was underpowered and because of a lower-than-expected incidence of neonatal sepsis, we performed a second trial (PPROMEXIL-2), aiming to randomize 200 patients to improve the evidence in near-term PPROM. STUDY DESIGN: In a nationwide multicenter study, nonlaboring women with PPROM between 34 and 37 weeks' gestational age were eligible for inclusion. Patients were randomized to IoL or expectant management (EM). The primary outcome measure was neonatal sepsis. RESULTS: From December 2009 until January 2011, we randomized 100 women to IoL and 95 to EM. Neonatal sepsis was seen in 3 neonates (3.0%) in the IoL-group versus 4 neonates (4.1%) in the EM group (relative risk, 0.74; 95% confidence interval, 0.17-3.2). One of the sepsis cases in the IoL group resulted in neonatal death because of asphyxia. There were no significant differences in secondary outcomes. CONCLUSION: The risk of neonatal sepsis after PPROM near term is low. Induction of labor does not reduce this risk.