Mortality and neurodevelopmental outcomes at 2 years' corrected age of very preterm infants with necrotising enterocolitis or spontaneous intestinal perforation: The EPIPAGE-2 cohort study.

PURPOSE: The primary objective was to evaluate the impact of necrotising enterocolitis (NEC) and spontaneous intestinal perforation (SIP) on mortality and neurodevelopmental outcomes at 2 years' corrected age (CA) in infants born before 32 weeks' gestation (WG). METHODS: We studied neurodevelopment at 2 years' CA of infants with NEC or SIP who were born before 32 WG from the EPIPAGE-2 cohort study. The primary outcome was death or the presence of moderate-to-severe motor or sensory disability defined by moderate-to-severe cerebral palsy or hearing or visual disability. The secondary outcome was developmental delay defined by a score < 2 SDs below the mean for any of the five domains of the Ages and Stages Questionnaire. RESULTS: At 2 years' CA, 46% of infants with SIP, 34% of infants with NEC, and 14% of control infants died or had a moderate-to-severe sensorimotor disability (p < 0.01). This difference was mainly due to an increase in in-hospital mortality in the infants with SIP or NEC. Developmental delay at 2 years' CA was more frequent for infants with SIP than controls (70.8% vs 44.0%, p = 0.02) but was similar for infants with NEC and controls (49.3% vs 44.0%, p = 0.5). On multivariate analysis, the likelihood of developmental delay was associated with SIP (adjusted odds ratio = 3.0, 95% CI 1.0-9.1) but not NEC as compared with controls. CONCLUSION: NEC and SIP significantly increased the risk of death or sensorimotor disability at 2 years' CA. SIP was also associated with risk of developmental delay at 2 years' CA.

Doxapram for apnoea of prematurity and neurodevelopmental outcomes at age 5-6 years.

OBJECTIVE: To assess the long-term neurodevelopmental impact of doxapram for treating apnoea of prematurity. DESIGN: Secondary analysis of the French national cohort study EPIPAGE-2. Recruitment took place in 2011. A standardised neurodevelopmental assessment was performed at age 5-6 years. A 2:1 propensity score matching was used to control for the non-randomised assignment of doxapram treatment. SETTING: Population-based cohort study. PATIENTS: All children born before 32 weeks' gestation alive at age 5-6 years. INTERVENTIONS: Blind and standardised assessment by trained neuropsychologists and paediatricians at age 5-6 years. MAIN OUTCOME MEASURES: Neurodevelopmental outcomes at age 5-6 years assessed by trained paediatricians and neuropsychologists: cerebral palsy, developmental coordination disorders, IQ and behavioural difficulties. A composite criterion for overall neurodevelopmental disabilities was built. RESULTS: The population consisted of 2950 children; 275 (8.6%) received doxapram. Median (IQR) gestational age was 29.4 (27.6-30.9) weeks. At age 5-6 years, complete neurodevelopmental assessment was available for 60.3% (1780 of 2950) of children and partial assessment for 10.6% (314 of 2950). In the initial sample, children receiving doxapram had evidence of greater clinical severity than those not treated. Doxapram treatment was associated with overall neurodevelopmental disabilities of any severity (OR 1.43, 95% CI 1.07 to 1.92, p=0.02). Eight hundred and twenty-one children were included in the 2:1 matched sample. In this sample, perinatal characteristics of both groups were similar and doxapram treatment was not associated with overall neurodevelopmental disabilities (OR 1.09, 95% CI 0.76 to 1.57, p=0.63). CONCLUSIONS: In children born before 32 weeks' gestation, doxapram treatment for apnoea of prematurity was not associated with neurodevelopmental disabilities.

Recommendations for use of adhesives on hospitalized newborns: A systematic review of the literature.

BACKGROUND: The skin is the largest organ in the human body. It provides multiple barrier functions, tactile or defensive, and acts as a mediator allowing for the attachment of vital monitoring devices with medical adhesives. Adhesives consist of several layers with varying compositions and properties. We aimed to provide recommendations for their use in the care of hospitalized neonates on the basis of a systematic literature review. METHODS: We searched PubMed for English or French articles published before May 29, 2020, using the keywords "adhesive," "tape,", "skin," and "neonat*." Recommendations were developed after review by a multidisciplinary group including 15 professionals and parent representatives. RESULTS: We identified 295 studies, and from 30 eligible studies we developed six recommendations according to four perspectives: assessment of the skin condition to improve the methods of application of the different adhesives and their removal; use of adhesives as a platform; and discouraging the regular use of semi-permeable dressings to compensate for the immaturity of the skin barrier. CONCLUSION: Skin lesions are common for hospitalized neonates. Use of adhesives may increase the occurrence of such lesions. Adhesives should be subject to good clinical practice guidelines. Health professionals caring for newborns should know the tools for screening and preventing skin lesions.

Excessive workload and insufficient night-shift remuneration are key elements of dissatisfaction at work for French neonatologists.

AIM: Neonatologists are exposed to ethical issues and unplanned emergencies that require 24-h in-house coverage. These elements may affect quality of life at work, which we surveyed. METHODS: This was a self-administered, voluntary and anonymous cross-sectional survey of French neonatologists. An online questionnaire was sent to members of the French Society of Neonatology from June to October 2022. RESULTS: Of approximately 1500 possible responses, 721 were analysed, with a response rate of 48%. Respondents were mostly women (77%), aged 35-50 years (50%), and hospital practitioners (63%). Reported weekly working time was over 50 h for 80%. Among the 650 neonatologists with on-call duty, 47% worked ≥5 shifts per month. For 80% of practitioners, on-call duty was perceived to have a negative impact on personal life; 49% indicated having sleep disorders. The mean satisfaction score at work was 5.7 ± 1.7 on a scale of 0-10. The main reasons for dissatisfaction were excessive working hours and insufficient remuneration for on-call duty. CONCLUSION: This first evaluation of the quality of life at work of French neonatologists showed high workload. The working conditions and specificities of NICU activity may have significant consequences for their mental health.

French Neonatal Society issues recommendations on preventing nasal injuries in preterm newborn infants during non-invasive respiratory support.

AIM: To issue practical recommendations regarding the optimal care of nasal skin when non-invasive ventilation support is used. METHODS: We performed a systematic search of PubMed to identify relevant papers published in English or French through December 2019. Different grades of evidence were evaluated. RESULTS: Forty-eight eligible studies. The incidence in preterm infants was high. The lesions were more frequent for preterm infants born under 30 weeks of gestational age and/or below 1500 g. The lesion was most often located on the skin of the nose but could also be found on the intranasal mucous membranes or elsewhere on the face. Nasal injuries appear early after the beginning of non-invasive ventilation at a mean of 2-3 days for cutaneous lesions and eight or nine for intranasal lesions. The most effective strategies to prevent trauma are the use of a hydrocolloid at the beginning of the support ventilation, the preferential use of a mask and the rotation of ventilation interfaces. CONCLUSION: Nasal injuries with continuous positive airway pressure treatment in preterm newborn infants were frequent and can induce pain, discomfort and sequelae. The immature skin of preterm newborn infants needs specific attention from trained caregivers and awareness by parents.

Practical recommendations on room sizes for hospitalised newborn infants and their families based on a systematic review of the literature.

AIM: Neonatal unit design may affect the neurodevelopment of hospitalised neonates and the well-being of parents and healthcare staff (HCS). We aimed to provide recommendations regarding the minimum area required for a hospital room for a single neonate and their family. METHODS: We searched PubMed and Web of Science for relevant articles published from 1 January 2011 to 1 May 2021 by using the keywords NICU and facility design. Recommendations were developed after internal and external review by a multidisciplinary group including 15 professionals and parent representatives. RESULTS: We identified 314 studies and developed six recommendations from four eligible studies. Recommendations for room size were developed according to three perspectives: opinions of users, who emphasised the need for a spacious room; proposals of organisations by HCS, which advocated for a minimum floor area of 11.2-18 m2 in a single non-family room and 15.3-24 m2 in a single-family room; and simulation methods indicating that the minimum floor area in the neonatal unit should be 18.5-24 m2 . CONCLUSION: Units need to provide a minimum room size to allow for optimal newborn development and a better experience for parents and caregivers.

[Caregivers' experiences with extreme prematurity]. / Vécu des soignants face à l'extrême prématurité.

Neonatal intensive care units receive very immature premature newborns. Mortality and morbidity rates remain high in this particularly fragile population. Caregivers involved with the child and his or her parents may experience moral distress. There are few studies on the experience of caregivers in these situations. Training, service architecture and sharing of experiences with specifically trained psychologists can improve this experience in these highly technical services.

Nebulized curcumin protects neonatal lungs from antenatal insult in rats.

Intrauterine growth restriction (IUGR) increases the risk of bronchopulmonary dysplasia (BPD), one of the major complications of prematurity. Antenatal low-protein diet (LPD) exposure in rats induces IUGR and mimics BPD-related alveolarization disorders. Peroxisome proliferator-activated receptor-γ (PPARγ) plays a key role in normal lung development and was found deregulated following LPD exposure. The objective of this article was to investigate the effects of nebulized curcumin, a natural PPARγ agonist, to prevent IUGR-related abnormal lung development. We studied rat pups antenatally exposed to an LPD or control diet (CTL) and treated with nebulized curcumin (50 mg/kg) or vehicle from postnatal (P) days 1 to 5. The primary readouts were lung morphometric analyses at P21. Immunohistochemistry (P21) and microarrays (P6 and P11) were compared within animals exposed to LPD versus controls, with and without curcumin treatment. Quantitative morphometric analyses revealed that LPD induced abnormal alveolarization as evidenced by a significant increase in mean linear intercept (MLI) observed in P21 LPD-exposed animals. Early curcumin treatment prevented this effect, and two-way ANOVA analysis demonstrated significant interaction between diet and curcumin both for MLI [F(1,39) = 12.67, P = 0.001] and radial alveolar count at P21 [F(1,40) = 6.065, P = 0.0182]. Immunohistochemistry for fatty acid binding protein 4 (FABP4), a major regulator of PPARγ pathway, showed a decreased FABP4+ alveolar cell density in LPD-exposed animals treated by curcumin. Transcriptomic analysis showed that early curcumin significantly prevented the activation of profibrotic pathways observed at P11 in LPD-exposed animals. Nebulized curcumin appears to be a promising strategy to prevent alveolarization disorders in IUGR rat pups, targeting pathways involved in lung development.

Premedication practices for neonatal tracheal intubation: Results from the EPIPPAIN 2 prospective cohort study and comparison with EPIPPAIN 1.

To describe the frequency and nature of premedication practices for neonatal tracheal intubation (TI) in 2011; to identify independent risk factors for the absence of premedication; to compare data with those from 2005 and to confront observed practices with current recommendations. Data concerning TI performed in neonates during the first 14 days of their admission to participating neonatal/pediatric intensive care units were prospectively collected at the bedside. This study was part of the Epidemiology of Procedural Pain in Neonates study (EPIPPAIN 2) conducted in 16 tertiary care units in the region of Paris, France, in 2011. Multivariate analysis was used to identify factors associated with premedication use and multilevel analysis to identify center effect. Results were compared with those of the EPIPPAIN 1 study, conducted in 2005 with a similar design, and to a current guidance for the clinician for this procedure. One hundred and twenty-one intubations carried out in 121 patients were analyzed. The specific premedication rate was 47% and drugs used included mainly propofol (26%), sufentanil (24%), and ketamine (12%). Three factors were associated with the use of a specific premedication: nonemergent TI (Odds ratio (OR) [95% CI]: 5.3 [1.49-20.80]), existence of a specific written protocol in the ward (OR [95% CI]:4.80 [2.12-11.57]), and the absence of a nonspecific concurrent analgesia infusion before TI (OR [95% CI]: 3.41 [1.46-8.45]). No center effect was observed. The specific premedication rate was lower than the 56% rate observed in 2005. The drugs used were more homogenous and consistent with the current recommendations than in 2005, especially in centers with a specific written protocol. Premedication use prior to neonatal TI was low, even for nonemergent procedures. Scientific consensus, implementation of international or national recommendations, and local written protocols are urgently needed to improve premedication practices for neonatal intubation.

Efficacy and Safety Aspects of Remifentanil Sedation for Intubation in Neonates: A Retrospective Study.

Objective: To evaluate the efficacy and safety of remifentanil as a premedication in neonates undergoing elective intubation. Study Design: This retrospective study focused on neonates admitted to the Neonatal Intensive Care Unit of Port-Royal, Paris Centre University Hospitals, France, between June 2016 and November 2017, who received remifentanil before an elective intubation. First, atropine (10 µg/kg) was administered intravenously as a bolus, followed by remifentanil, which was administrated continuously. The dose of remifentanil was reduced twice during the study period in order to administer the minimum effective dose and thus reduce possible adverse events. Results: Fifty-four neonates were exposed to remifentanil and atropine. The intubating conditions were excellent or good for 46 procedures (85%) and the median Acute Pain in Newborn Infants score was 2 (IQ 25-75: 0-5) before the sedation, 1 (0-2) during the laryngoscopy, and 0 (0-0) after the intubation. The intubation was successful at the first attempt for 18 patients (33%). Chest wall rigidity occurred in 6 procedures (11%), other respiratory problems in 5 (9%), and laryngospasm in 1 (2%). Some of the procedures were complicated by bradycardia (23%) or desaturation (37%). Conclusions: Remifentanil and atropine prior to intubation provided satisfactory intubating conditions in neonates. Nevertheless, severe adverse effects (such as chest wall rigidity) are a potential risk, possibly related to the total dose received. These data do not support the safety of using remifentanil alone prior to intubation in neonates.

Association of serum angiogenic factors with bronchopulmonary dysplasia. The ANGIODYS cohort study.

OBJECTIVES: Angiogenic factors may be involved in lung development. To evaluate the relations between maternal and cord blood angiogenic factors (sFlt-1, placental growth factor [PlGF], soluble endogline [sEng], transforming growth factor ß [TGF-beta]) and their association with moderate and severe bronchopulmonary dysplasia (BPD) in very preterm growth-restricted infants. STUDY DESIGN: Prospective monocentric cohort study. Twenty-four mother-child dyads featuring antepartum preeclampsia, intra-uterine growth restriction (IUGR) and birth before 30 weeks' gestation were included. This ensured a 80% power to test whether sFlt-1 maternal levels would be twice as high in cases of BPD as in the absence of BPD. MAIN OUTCOME MEASURES: Four pro/anti-angiogenic factors from two pathways (sFlt-1, PlGF and sEng, TGF-beta) were measured in maternal serum before delivery (at the time of hospitalization or the day of birth) and in neonates' cord blood. Neonatal outcome was moderate to severe BPD, defined as oxygen requirement for at least 28 days and persistent need for oxygen or ventilatory support at 36 weeks' postmenstrual age. RESULTS: sFlt-1 levels were positively correlated in maternal serum and cord blood (rs = 0.83, p < .001) but levels of PlGF and TGF-beta and its receptor sEng were not. Among all the factors studied in cord and maternal blood, none was associated with BPD. CONCLUSIONS: In IUGR preterm babies born before 30 weeks' gestation from preeclamptic mothers, serum sFlt-1, PlGF and sEng, TGF-ß levels were not correlated with BPD. The increased BPD risk in preterm neonates born from preeclamptic mothers cannot be related to high sFlt-1 levels.

Bronchopulmonary dysplasia in neonates born to mothers with preeclampsia: Impact of small for gestational age.

BACKGROUND AND OBJECTIVES: Small for gestational age and preeclampsia have both been described as risk factors for bronchopulmonary dysplasia in preterm neonates, but their respective role in the occurrence of bronchopulmonary dysplasia is debated. We evaluated the relation between small for gestational age and bronchopulmonary dysplasia in neonates born to mothers with preeclampsia. We hypothesized that low birth weight is still associated with bronchopulmonary dysplasia in this homogeneous population. METHODS: Retrospective single-center cohort study including 141 neonates born between 24 and 30 weeks' gestation to mothers with preeclampsia. The main outcome measure was moderate to severe bronchopulmonary dysplasia at 36 weeks' postmenstrual age. Neonates born small for gestational age (birthweight < 10th percentile on the AUDIPOG curves) were compared to those with appropriate birthweight for gestational age by bivariable analyses and logistic regression models, estimating odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Bronchopulmonary dysplasia rates were 61.5% (32/52) and 27.4% (20/73) for small for gestational age and appropriate birthweight for gestational age neonates (p < .001). On adjustment for gestational age and other confounding factors, the risk of moderate to severe bronchopulmonary dysplasia was greater for small for gestational age than appropriate birthweight for gestational age neonates (adjusted OR = 5.9, 95% CI [2.2-15.4]), as was the composite outcome death or moderate to severe bronchopulmonary dysplasia (adjusted OR = 4.7, 95% CI [1.9-11.3]). CONCLUSIONS: Small for gestational age was associated with bronchopulmonary dysplasia in very preterm neonates born to mothers with preeclampsia. REGISTRATION NUMBER: CNIL no. 1747084.

Lung microRNA deregulation associated with impaired alveolarization in rats after intrauterine growth restriction.

Intrauterine growth restriction (IUGR) was recently described as an independent risk factor of bronchopulmonary dysplasia, the main respiratory sequelae of preterm birth. We previously showed impaired alveolarization in rat pups born with IUGR induced by a low-protein diet (LPD) during gestation. We conducted a genome-wide analysis of gene expression and found the involvement of several pathways such as cell adhesion. Here, we describe our unbiased microRNA (miRNA) profiling by microarray assay and validation by qPCR at postnatal days 10 and 21 (P10 and P21) in lungs of rat pups with LPD-induced lung-alveolarization disorder after IUGR. We identified 13 miRNAs with more than two-fold differential expression between control lungs and LPD-induced IUGR lungs. Validated and predicted target genes of these miRNAs were related to "tissue repair" at P10 and "cellular communication regulation" at P21. We predicted the deregulation of several genes associated with these pathways. Especially, E2F3, a transcription factor involved in cell cycle control, was expressed in developing alveoli, and its mRNA and protein levels were significantly increased at P21 after IUGR. Hence, IUGR affects the expression of selected miRNAs during lung alveolarization. These results provide a basis for deciphering the mechanistic contributions of IUGR to impaired alveolarization.

Transcriptomic regulations in oligodendroglial and microglial cells related to brain damage following fetal growth restriction.

Fetal growth restriction (FGR) is a major complication of human pregnancy, frequently resulting from placental vascular diseases and prenatal malnutrition, and is associated with adverse neurocognitive outcomes throughout life. However, the mechanisms linking poor fetal growth and neurocognitive impairment are unclear. Here, we aimed to correlate changes in gene expression induced by FGR in rats and abnormal cerebral white matter maturation, brain microstructure, and cortical connectivity in vivo. We investigated a model of FGR induced by low-protein-diet malnutrition between embryonic day 0 and birth using an interdisciplinary approach combining advanced brain imaging, in vivo connectivity, microarray analysis of sorted oligodendroglial and microglial cells and histology. We show that myelination and brain function are both significantly altered in our model of FGR. These alterations, detected first in the white matter on magnetic resonance imaging significantly reduced cortical connectivity as assessed by ultrafast ultrasound imaging. Fetal growth retardation was found associated with white matter dysmaturation as shown by the immunohistochemical profiles and microarrays analyses. Strikingly, transcriptomic and gene network analyses reveal not only a myelination deficit in growth-restricted pups, but also the extensive deregulation of genes controlling neuroinflammation and the cell cycle in both oligodendrocytes and microglia. Our findings shed new light on the cellular and gene regulatory mechanisms mediating brain structural and functional defects in malnutrition-induced FGR, and suggest, for the first time, a neuroinflammatory basis for the poor neurocognitive outcome observed in growth-restricted human infants. GLIA 2016;64:2306-2320.

Clinical Utility and Safety of a Model-Based Patient-Tailored Dose of Vancomycin in Neonates.

Pharmacokinetic modeling has often been applied to evaluate vancomycin pharmacokinetics in neonates. However, clinical application of the model-based personalized vancomycin therapy is still limited. The objective of the present study was to evaluate the clinical utility and safety of a model-based patient-tailored dose of vancomycin in neonates. A model-based vancomycin dosing calculator, developed from a population pharmacokinetic study, has been integrated into the routine clinical care in 3 neonatal intensive care units (Robert Debré, Cochin Port Royal, and Clocheville hospitals) between 2012 and 2014. The target attainment rate, defined as the percentage of patients with a first therapeutic drug monitoring serum vancomycin concentration achieving the target window of 15 to 25 mg/liter, was selected as an endpoint for evaluating the clinical utility. The safety evaluation was focused on nephrotoxicity. The clinical application of the model-based patient-tailored dose of vancomycin has been demonstrated in 190 neonates. The mean (standard deviation) gestational and postnatal ages of the study population were 31.1 (4.9) weeks and 16.7 (21.7) days, respectively. The target attainment rate increased from 41% to 72% without any case of vancomycin-related nephrotoxicity. This proof-of-concept study provides evidence for integrating model-based antimicrobial therapy in neonatal routine care.

Biological Impact of Recent Guidelines on Parenteral Nutrition in Preterm Infants.

OBJECTIVES: Recent guidelines for preterm neonates recommend early initiation of parenteral nutrition (PN) with high protein and relatively high caloric intake. This review considers whether these changes could influence homeostasis in very preterm infants during the first few postnatal weeks. METHODS: This systematic review of relevant literature from searches of PubMed and recent guidelines was reviewed by investigators from several perinatal centers in France. RESULTS: New recommendations for PN could be associated with metabolic acidosis via the increase in the amino acid ion gap, hyperchloremic acidosis, and ammonia acidosis. The introduction of high-intake amino acids soon after birth could induce hypophosphatemia and hypercalcemia, simulating a "repeat feeding-like syndrome" and could be prevented by the early intake of phosphorus, especially in preterm infants born after fetal growth restriction. Early high-dose amino acid infusions are relatively well tolerated in the preterm infant with regard to renal function. Additional studies, however, are warranted to determine markers of protein intolerance and to specify the optimal composition and amount of amino acid solutions. CONCLUSIONS: Optimal PN following new guidelines in very preterm infants, despite their demonstrated benefits on growth, may induce adverse effects on ionic homeostasis. Clinicians should implement appropriate monitoring to prevent and/or correct them.

Impact of common treatments given in the perinatal period on the developing brain.

BACKGROUND: Over the last decades, considerable progress has been made in the perinatal management of high-risk preterm neonates, changing the landscape of pathological conditions associated with neurological impairments. Major focal destructive lesions are now less common, and the predominant neuropathological lesion is diffuse white-matter damage in the most immature infants. Similarly, over the last few years, we have observed a trend towards a decrease in neurological impairment in the absence of treatments specifically aimed at neuroprotection. OBJECTIVES: We examined whether recent changes in treatment strategies in perinatal care during the perinatal period could have had an indirect beneficial impact on the occurrence of brain lesions and their consequences. METHODS: Thus, we reviewed the effects of the most common treatments administered during the perinatal period to the mother or to very preterm infants on brain damage and neurocognitive follow-up. RESULTS: Antenatal steroids and exogenous surfactant are the two main treatments capable of leading to neuroprotection in very preterm infants. Randomized controlled trials are currently investigating the effects of inhaled nitric oxide and erythropoietin, while antenatal magnesium sulphate and caffeine are also likely to provide some neuroprotection, but this needs to be further investigated. Finally, other common treatments against pain, haemodynamic failure and patent ductus arteriosus have conflicting or no effects on the developing brain. CONCLUSION: While specific neuroprotective drugs are still awaited, recent advances in perinatal care have been associated with an unexpected but significant decrease in the incidence of both severe brain lesions and neurological impairment.

Effect of two models of intrauterine growth restriction on alveolarization in rat lungs: morphometric and gene expression analysis.

Intrauterine growth restriction (IUGR) in preterm infants increases the risk of bronchopulmonary dysplasia, characterized by arrested alveolarization. We evaluated the impact of two different rat models (nitric oxide synthase inhibition or protein deprivation) of IUGR on alveolarization, before, during, and at the end of this postnatal process. We studied IUGR rat pups of dams fed either a low protein (LPD) or a normal diet throughout gestation and pups of dams treated by continuous infusion of Nω-nitro-L-arginine methyl ester (L-NAME) or its diluent on the last four days of gestation. Morphometric parameters, alveolar surface (Svap), mean linear intercept (MLI) and radial alveolar count (RAC) and transcriptomic analysis were determined with special focus on genes involved in alveolarization. IUGR pups regained normal weight at day 21 in the two treated groups. In the LPD group, Svap, MLI and RAC were not different from those of controls at day 4, but were significantly decreased at day 21, indicating alveolarization arrest. In the L-NAME group, Svap and RAC were significantly decreased and MLI was increased at day 4 with complete correction at day 21. In the L-NAME model, several factors involved in alveolarization, VEGF, VEGF-R1 and -R2, MMP14, MMP16, FGFR3 and 4, FGF18 and 7, were significantly decreased at day 4 and/or day 10, while the various factors studied were not modified in the LPD group. These results demonstrate that only maternal protein deprivation leads to sustained impairment of alveolarization in rat pups, whereas L-NAME impairs lung development before alveolarization. Known growth factors involved in lung development do not seem to be involved in LPD-induced alveolarization disorders, raising the question of a possible programming of altered alveolarization.