Évolution de la mortalité, de la morbidité et de la prise en charge des grands prématurés dans un centre de niveau III : comparaison des années 2000, 2005 et 2010

Preterm brain injury: Germinal matrix-intraventricular hemorrhage and post-hemorrhagic ventricular dilatation

Germinal matrix hemorrhage and intraventricular hemorrhages (GMH-IVH) remain a common and clinically significant problem in preterm infants, particularly extremely preterm infants. A large GMH-IVH is often complicated by posthemorrhagic ventricular dilation (PHVD) or parenchymal hemorrhagic infarction and is associated with an increased risk of adverse neurologic sequelae. The widespread use of cranial ultrasonography since the early 1980s has shown a gradual decrease in the incidence of GMH-IVH and has helped with the identification of antenatal and perinatal risk factors and timing of the lesion. The increased use of magnetic resonance imaging (MRI) has contributed to more detailed visualization of the site and extent of the GMH-IVH. In addition, MRI has contributed to the awareness of associated white matter changes as well as associated cerebellar hemorrhages. Although GMH-IVH and PHVD still cannot be prevented, cerebrospinal fluid drainage initiated in the early stage of PHVD development seems to be associated with a better neurodevelopmental outcome. Further studies are underway to improve treatment strategies for PHVD and to potentially prevent and repair GMH-IVH and PHVD and associated brain injury. This chapter discusses the pathogenesis, incidence, risk factors, and management, including preventive measures, of GHM-IVH and PHVD.

Analysis of mutations of MDR3 exons 9 and 23 in infants with parenteral nutrition-associated cholestasis

The aim of this study was to investigate mutations of multidrug resistance 3 (MDR3) exons 9 and 23 in infants with parenteral nutrition-associated cholestasis (PNAC). A total of 41 infants with PNAC were enrolled in the study. Genomic DNA was extracted from the peripheral venous blood leukocytes of each patient and MDR3 exons 9 and 23 were amplified by polymerase chain reaction. One patient was identified who carried a frameshift mutation in MDR3 exon 23 (C.2793) that was caused by the insertion of a single adenine residue, while mutations were not found in MDR3 exon 23 in the other 40 patients. The clinical features of the patient with the MDR3 exon 23 frameshift mutation included high serum γ-glutamyl transferase levels, the absence of biliary dilatation and deformity in magnetic resonance cholangiopancreatography, and abnormal electrical capacitance tomography imaging of the liver. No mutations in MDR3 exon 9 were identified in any of the patients. All 41 PNAC patients recovered following oral ursodeoxycholic acid treatment. The C.2793 frameshift mutation in MDR3 exon 23 is potentially associated with the development of PNAC in infants.

Comparison in outcomes at two-years of age of very preterm infants born in 2000, 2005 and 2010

Objective

To investigate alteration in 2-year neurological/behavioral outcomes of very preterm infants born in a French level three neonatal intensive care unit.

Methods

We conducted a prospective, comparative study of very preterm infants born before 33 weeks’ gestation at 5-year intervals in 2000, 2005 and 2010 at Rouen University Hospital. Neonatal mortality/morbidities, ante- and neonatal treatments, and at age 2 years motor, cognitive and behavioral data were collected by standardized questionnaires.

Results

We included 536 very preterm infants. Follow-up rates at two years old were 78% in 2000, 93% in 2005 and 92% in 2010 respectively. No difference in gestational age, birthweight, neonatal mortality/morbidities was observed except a decrease in low grade subependymal/intraventricular hemorrhages. Care modifications concerned use of antenatal magnesium sulfate, breast-feeding and post-natal corticosteroid therapy. Significant improvement in motor outcome and dramatic decrease in cerebral palsy rates (12% in 2000, 6% in 2005, 1% in 2010, p<0.001) were observed, as were improvements in feeding behavior. Although a non significant difference to better psychosocial behavior was reported, there was no difference in cognitive outcome.

Conclusions

Improvement in neuromotor outcome and behavior was reported. This could be due to multiple modifications in care: including administration of magnesium sulfate to women at risk of preterm birth, increase in breast-feeding, decrease in low grade subependymal/intraventricular hemorrhages, and decrease in post-natal corticosteroid therapy, all of which require further investigation in other studies. Extended follow-up until school age is mandatory for better detection of cognitive, learning and behavioral disorders.

[Very preterm births in French Polynesia: update and proposal for follow-up]

INTRODUCTION

The care of premature infants in French Polynesia is complicated by this country's geographic isolation. We undertook an evaluation of the medical care of very premature infants (VPIs) to find local solutions to this problem.

OBJECTIVES

The objectives were to determine the incidence, mortality, and the short- and long-term outcome of very preterm infants in French Polynesia.

METHODS

We retrospectively reviewed the medical charts of all infants born alive at<32 gestational age (GA) and>24 GA from January 2007 to December 2011. Perinatal characteristics and outcomes were examined by univariate and multivariate analysis.

RESULTS

In total, 204 VPIs were born during the 5-year study period, comprising 0.9% of all births. Infants less than 28 GA comprised 0.1% of all births. Sixty-two percent of mothers were of extreme age including 43% less than 25 years old. Prematurity was attributed to spontaneous preterm labor in 63% of cases and preeclampsia in 29%. Spontaneous multiple pregnancies comprised 15% of the cases. Alcohol and tobacco consumption were frequently noted (>8% and 26% mothers, respectively). Seventy-eight percent of VPIs had received prenatal steroids. Intrauterine growth was normal in 89%. Mortality occurred in 9.3% (19 patients). Mortality was higher with lower gestational age (P<0.05) and absence of prenatal steroids (P<0.05) in univariate and multivariate analysis. The primary cause of death was sepsis. Hyaline membrane disease occurred in 44% of patients, 80% of whom received surfactant therapy. In total, 16.2% newborns developed bronchodysplasia, 3.4% necrotizing enterocolitis, 3% cerebral hemorrhage, and 1.5% leukomalacia. Long-term outcome was marked by 52% of the patients lost to follow-up by 2 years of age, mostly because of geographic isolation. For the 72 patients followed-up, four developed asthma and three cerebral palsy; 70% were attending school by 3 years of age.

CONCLUSIONS

The incidence, mortality, and morbidity of very preterm birth in French Polynesia are comparable to reports from metropolitan centers in France. Conversely, nearly one-half of the patients were lost to follow-up, precluding meaningful information on intellectual development and other outcomes. We recommend organizing a long-term follow-up network to detect cognitive sequelae and adapting such a system to the geographical residence of French Polynesian families.

[Course and neurological/behavioral development of preterm children]

Preterm birth remains a public health priority given that one child out of ten is born before 37 weeks of gestation. Survival without major neonatal morbidity has increased in high-income countries, in particular in France and in cases of extreme preterm birth before 27 weeks of gestation. Rate of severe handicaps, such as cerebral palsy, is probably decreasing, but specific cognitive disabilities in a variety of domains remain frequent, interfering with normal learning abilities at school and explaining the high rate of special education needs. Prevalence of sequelae increases when gestational age at birth decreases. However, because there are more moderate to late preterm children compared to very preterm children, the absolute number of children with specific cognitive or neurological disabilities is equivalent in these two groups. Better characterization of the development in a recent cohort of very preterm children is necessary to improve the early detection of variations in normal neurodevelopment and to propose trials with remediation actions targeting working memory and language for example. These protocols could decrease the rates of learning disabilities at school.

Effectiveness of vitamin A in the prevention of complications of prematurity

BACKGROUND

To assess the effectiveness of vitamin A supplementation in very low birth weight (VLBW) infants to prevent complications of prematurity.

METHODS

This was a retrospective cohort study to determine the effectiveness of vitamin A in preventing complications of prematurity in VLBW infants. Vitamin A was delivered intramuscularly at a dose of 5000 IU, three times weekly during the first 28 days of life.

RESULTS

Of the 187 eligible VLBW infants, we excluded from the analysis (due to death or transfer to another hospital), 16 infants weighing <1000 g and 17 weighing 1000-1500 g. Sixty VLBW infants received the vitamin supplement. We observed no differences between the groups in the duration of oxygen therapy or in the risk of bronchopulmonary dysplasia. The risk of sepsis was up to three times higher among the infants who were given the vitamin A supplement.

CONCLUSION

Given the increased risk of sepsis in patients weighing >1000 g, the risk associated with repeated intramuscular injections of vitamin A and the modest clinical results described, we do not believe the universal administration of vitamin A to VLBW infants to be justified as prophylaxis for bronchopulmonary dysplasia.

Correlation between mutation of MDR3 gene exon 6 and parenteral nutrition-associated cholestasis of preterm infants

The aim of this study was to investigate the association between the mutation of multidrug resistance 3 (MDR3) exon 6 and parenteral nutrition-associated cholestasis (PNAC) in preterm infants. A total of 41 preterm infants with PNAC formed the experimental group, and 56 preterm infants receiving total parenteral nutrition (TPN) for >14 days but without cholestasis formed the control group. Genomic DNA was extracted from peripheral venous blood leukocytes. Polymerase chain reaction was used to amplify exon 6 of the MDR3 gene. The target band of MDR3 gene exon 6 was identified in all blood samples from all cases. We identified five cases with C. 504 C>T heterozygous mutations of exon 6 of the MDR3 gene and 14 cases with C. 504 C>T homozygous mutations in the experimental group. In the control group, we identified seven cases with the C. 504 C>T homozygous mutation and six cases with the C. 504 C>T heterozygous mutation. The distribution of the T/C allele frequency of C. 504 in exon 6 of the MDR3 gene between the experimental group and control group was statistically significant (P<0.05). Further analysis revealed the odds ratio of the T/C allele frequency of the C. 504 mutation in exon 6 of the MDR3 gene between the experimental group and control group to be 0.316. Point mutation C. 485 T>A was detected in one case in the experimental group. The C. 504 C>T and C. 485 T>A MDR3 mutations in exon 6 are possibly responsible for the development of PNAC in infants. C. 504 C>T may not be the only risk factor of neonatal PNAC. In order to further confirm the association between exon 6 of the MDR3 gene and PNAC, a large-sample multicenter study should be carried out.