Neonatal and 5-year outcomes after birth at 30-34 weeks of gestation

OBJECTIVE: To evaluate the rates of in-hospital death, neonatal complications, and 5-year outcomes of infants born at 30-34 weeks of gestation. METHODS: In nine regions of France, all 2,020 stillbirths and live births at 30, 31, and 32 weeks in 1997 and all 457 births at 33 and 34 weeks in April and October 1997 were recorded. Survivors were evaluated at 5 years of age. RESULTS: Increasing gestational age from 30 to 34 weeks was associated with progressive decreases in in-hospital mortality (from 8.1% to 0.4%) and neonatal complications (respiratory distress syndrome, 43.8% to 2.6%; maternofetal infections, 7.2% to 2.6%; and severe white matter injury, 5.5% to 1.3%). Although infants at 33 and 34 weeks of gestation rarely experienced necrotizing enterocolitis, bronchopulmonary dysplasia, or nosocomial infections, they still required endotracheal ventilation, antibiotics, or parenteral nutrition. At 5 years of age, older gestational age was associated with significant decreases in rates of cerebral palsy (6.3% at 30 weeks and 0.7% at 34 weeks) and mild to severe cognitive impairments (35.3% at 30 weeks and 23.9% at 34 weeks). In singletons, preterm rupture of membranes or preterm labor carried an increased risk of cerebral palsy but not of cognitive impairment. CONCLUSION: Neonates born at 30-34 weeks experienced substantial morbidity and often required admission to neonatal intensive care units. These outcomes suggest that prolonging pregnancies beyond 34 weeks may be desirable whenever possible. Infants born at 30-34 weeks should be carefully monitored to ensure prompt detection and management of neurodevelopmental impairment.     

Heart rate variability in preterm infants and maternal smoking during pregnancy

Objective  Tobacco smoke exposure increases the risk of premature birth and of dying of sudden infant death syndrome (SIDS). Prematurity significantly increases the risk of dying of SIDS, but mechanisms underlying this epidemiological finding are unclear. The cumulated effect of both prematurity and prenatal exposure to nicotine on autonomic heart rate control has not been studied. Methods  Using coarse-graining spectral analysis, we compared heart rate variability (HRV) indices of preterm newborns at 33–34 weeks post-conceptional age from smoking (n = 19) and non-smoking (n = 21) mothers. Assessment of tobacco exposure relied on maternal reports and newborns cotinine analysis. We observed how indicators of HRV depended on gestational age at birth. Results  At 33–34 weeks postconceptional age, the newborns from smoking mothers had lower HRV low frequency power normalised to the total spectral power (LF/TP) than the control group (median values: 8% vs. 15% respectively, p < 0.02). In the non-smoking group, RR-interval values and total HRV power were correlated with gestational age at birth, with a shorter RR and a lower total HRV power in lesser gestational ages (ρ = 0.67, p = 0.03, ρ = 0.71, p = 0.003 respectively). This correlation was not observed for RR values in the group with smoking mothers.     

Analysis of NREM sleep in children with Prader–Willi syndrome and the effect of growth hormone treatment

ObjectivesOnly few studies are available in the literature on sleep in children with Prader–Willi syndrome (PWS) and one single study analyzed the cyclic alternating pattern (CAP) in young adults with PWS, showing that patients with a higher proportion of A1 subtypes presented less severe GH deficiency. The aims of our study were to evaluate CAP in children with PWS compared to an age-matched control group and to evaluate the differences between PWS children with (GH+) and without (GH?) GH therapy.MethodsLaboratory polysomnographic sleep recordings were obtained from 30 children with PWS (17 GH? and 13 GH+ patients) and 15 age-matched normal controls.ResultsCompared to controls, PWS children had a reduction of sleep efficiency, of sleep stage 2 and of REM sleep. GH? PWS patients showed a global decrease in total CAP rate during S1 and S2 but not in SWS. In GH+ PWS patients, SWS CAP rate and A1 index were increased vs. GH? children.DiscussionThe decrease in total CAP rate and all A subtypes might suggest the presence of a decreased NREM sleep instability in our PWS children and can be considered to be in agreement with the reported generalized hypoarousal state of PWS subjects. GH therapy is likely to increase CAP rate and A1 index during SWS in PWS patients.     

Ophthalmoplegia as the presenting muscle-related manifestation of myotonic dystrophy

Introduction

Myotonic dystrophy type 1 (DM1) is a genetic disorder caused by expanded CTG repeats within the 3’ untranslated region of the dystrophia myotonia protein kinase (DMPK) gene on chromosome 19. Diplopia is rare in this disease and has only been reported in patients with diffuse neuromuscular disorders.

Observation

We report here on the case of a 58-year-old woman in whom ophthalmoplegia was the first neuromuscular manifestation of DM1 and led to the diagnosis. Among the multisystem abnormalities associated with DM1, muscle-related symptoms are prominent, and usually involve the facial and neck muscles early on in the disease. This case provides additional evidence of oculomotor muscle involvement in DM1.

Conclusion

DM1 should, therefore, be considered during the diagnostic workup of any unexplained ophthalmoplegia of muscle origin, especially if there has been a previous history of cataract, even in the absence of typical muscle-related features.     

Very preterm birth: who has access to antenatal corticosteroid therapy?

Burguet A, Ferdynus C, Thiriez G, Bouthet M‐F, Kayemba‐Kays S, Sanyas P, Menget A, Mulin B, Riethmuller D, Maillet R, Brousse C, Magnin G, Boisselier P, Sagot P, Pierre F, Gouyon B, Gouyon J‐B. Very preterm birth: who has access to antenatal corticosteroid therapy? Paediatric and Perinatal Epidemiology 2010; 24: 63–74. We describe the administration of antenatal corticosteroid therapy (ACT) for liveborn very preterm neonates in a population‐based study. A total of 790 very preterm neonates (between 24 and 31 full weeks of gestation) were included in this regionally defined population of very preterm neonates in France. The main outcome measure was non‐access to ACT. Data were analysed using logistic and polytomous models to control for neonatal and sociodemographic characteristics, mechanisms of very preterm birth and neonatal network organisation. As compared with level III, births in levels I‐II maternity units were closely related to non‐access to ACT (60.1% vs. 8.8%), but not to pregnancy follow‐up (19.7% vs. 17.8%). Only 6.3% of very preterm neonates that benefited from antepartum referral did nor receive ACT. Births associated with rupture of membranes and gestational hypertension were significantly more often transferred to level‐III units (73.8% and 68.3% respectively) than those due to maternal bleeding and spontaneous labour (57.0% and 50.7% respectively), and the neonates had a lower probability of not receiving ACT (8.5%, 11.5%, 23.0%, 31.2% respectively). Very preterm neonates referred in utero to a level‐III unit came from a more favourable socio‐economic environment. Non‐access to ACT was more often observed in neonates born to 14‐ to 24‐year‐old mothers, smokers, of low socio‐economic status, and preterm birth resulting from maternal bleeding or spontaneous labour. These data from a French regional study show that access to ACT is not only explained by practitioners' support of recommendations. In our population‐based study, ACT access was related to socio‐economic factors and to the mechanisms of very preterm birth. Improving the rate of access to ACT should take these organisational, medical and socio‐economic dimensions into account.     

Cardiovascular control during sleep in infants: Implications for Sudden Infant Death Syndrome

In infants the cardiorespiratory system undergoes significant functional maturation after birth and these changes are sleep-state dependent. Given the immaturity of these systems it is not surprising that infants are at risk of cardiorespiratory instability, especially during sleep. A failure of cardiovascular control mechanisms in particular is believed to play a role in the final event of Sudden Infant Death Syndrome (SIDS). The “triple risk model” describes SIDS as an event that results from the intersection of three overlapping factors: (1) a vulnerable infant, (2) a critical development period in homeostatic control, and (3) an exogenous stressor. This review summarises normal development of cardiovascular control during sleep in infants and describes the association of impaired cardiovascular control with the three overlapping factors proposed to be involved in SIDS pathogenesis.