[Is it possible to protect the preterm infant brain and to decrease later neurodevelopmental disabilities?]. / Est-il possible de protéger le cerveau de l'enfant né prématuré et de diminuer le taux de séquelles neuro-développementales ?

With improving neonatal survival for very premature babies, the challenge for neonatalogists is to ameliorate outcome of surviving babies. Several pharmacological molecules have been shown to have protective effects in different types of in vitro or in vivo animal models of acquired cerebral brain damages. However translational research and conduction of therapeutic trials in human remain difficult due to failure to recognize start of deleterious cascade leading to cerebral damage and additional toxic effect of potential protective molecules. This review concentrates on best evidence emerging in recent years on prevention on brain damage by early drug administration. It has been shown in two randomised trials that prenatal low-dose of magnesium sulphate does not increase paediatric mortality in very-preterm infants and has non significant neuroprotective effects on occurrence of motor dysfunction (with a 0.62 odds ratio in the French trial Premag and 0.71 relative risk in the Australian trial ACTOMgSO4), justifying that magnesium sulphate should be discussed as a stand-alone treatment or as part of a combination treatment, at least in the context of clinical trials. Antenatal corticosteroid therapy increases the survival of very-preterm infants, including the most immature. Moreover in an observational recent study of the Epipage cohort, it has been observed a significant decrease in white matter injury in the 28-32 weeks' gestation group but no effect on long term outcome and behaviour. Conversely in the most immature of the 24-27 weeks' gestation group, no effect has been detected either in white matter injury incidence or in long term outcome rates. Caffeine has a protective effect since a decrease in cerebral palsy has been noted in the caffeine group in a randomised trial studying caffeine versus placebo. For what concern other widely used potential protective molecules during the perinatal period, there is no evidence of cerebral protection with indometacine, nitric oxide, eythropoietin, phenobarbital, and etamsylate. Due to their specific properties, a careful evaluation of aspirin, anaesthetic drugs and tocolytics should be done in the next months.

[Neuroprotection for preterm infants with antenatal magnesium sulphate]. / Protection cérébrale de l'enfant né prématuré par le sulfate de magnésium.

OBJECTIVE: To evaluate in preterm born children the neuroprotective benefits and the risks, at short- and long-term outcome, of the antenatal administration of magnesium sulphate (MgSO4) in women at imminent risk of preterm delivery. MATERIAL AND METHODS: Computer databases Medline, the Cochrane Library and the recommendations of various international scientific societies. RESULTS: Given the demonstrated benefit of antenatal MgSO4 intravenous administration on the reduction of cerebral palsy rates and the improvement of motor development in children born preterm, it is recommended for all women whose imminent delivery is expected or programmed before 32 weeks of gestation (WG) (grade A). The analysis of the literature finds no argument for greater benefit of antenatal MgSO4 administration in sub-groups of gestational age, or depending on the type of pregnancy (single or multiple pregnancy) or with the cause of preterm birth (NP2). Its administration is recommended before 32 WG, if single or multiple pregnancy, whatever the cause of prematurity (grade B). It is recommended 4g loading dose (professional consensus). With a loading dose of 4g intravenous (IV) in 20min, the serum magnesium is lower than with intramuscular suggesting a preference for the IV route (professional consensus). It is proposed to use a maintenance dose of 1g/h until delivery with a maximum recommended duration of 12hours without exceeding a cumulative dose of 50g (professional consensus). These doses are without severe adverse maternal side effects or adverse effects in newborns at short- and medium-term outcome (NP1). CONCLUSION: It is recommended to administer magnesium sulfate to the women at high risk of imminent preterm birth before 32 WG, whether expected or planned (grade A), with a 4g IV loading dose followed by a maintenance dose of 1g/h for 12hours (professional consensus), the pregnancy is single or multiple, whatever the cause of prematurity (professional consensus).

[Prevention of spontaneous preterm birth (excluding preterm premature rupture of membranes): Guidelines for clinical practice - Text of the Guidelines (short text)]. / Recommandations pour la pratique clinique : prévention de la prématurité spontanée et de ses conséquences (hors rupture des membranes) ­ Texte des recommandations (texte court).

OBJECTIVES: To determine the measures to prevent spontaneous preterm birth (excluding preterm premature rupture of membranes)and its consequences. MATERIALS AND METHODS: The PubMed database, the Cochrane Library and the recommendations from the French and foreign obstetrical societies or colleges have been consulted. RESULTS: In France, premature birth concerns 60,000 neonates every year (7.4 %), half of them are delivered after spontaneous onset of labor. Among preventable risk factors of spontaneous prematurity, only cessation of smoking is associated to a decrease of prematurity (level of evidence [LE] 1). This is therefore recommended (grade A). Routine screening and treatment of vaginal bacteriosis in general population is not recommended (grade A). Asymptomatic women with single pregnancy without history of preterm delivery and a short cervix between 16 and 24 weeks is the only population in which vaginal progesterone is recommended (grade B). A history-indicated cerclage is not recommended in case of only past history of conisation (grade C), uterine malformation (Professional consensus), isolated history of pretem delivery (grade B) or twin pregnancies in primary (grade B) or secondary (grade C) prevention of preterm birth. A history-indicated cerclage is recommended for single pregnancy with a history of at least 3 late miscarriages or preterm deliveries (grade A).). In case of past history of a single pregnancy delivery before 34 weeks gestation (WG), ultrasound cervical length screening is recommended between 16 and 22 WG in order to propose a cerclage in case of length<25mm before 24 WG (grade C). Cervical pessary is not recommended for the prevention of preterm birth in a general population of asymptomatic women with a twin pregnancy (grade A) and in populations of asymptomatic women with a short cervix (Professional consensus). Although the implementation of a universal transvaginal cervical length screening at 18-24 weeks of gestation in women with a singleton gestation and no history of preterm birth can be considered by individual practitioners, this screening cannot be universally recommended. In case of preterm labor, (i) it is not possible to recommend one of the methods over another (ultrasound of the cervical length, vaginal examination, fetal fibronectin) to predict preterm birth (grade B); (ii) routine antibiotic therapy is not recommended (grade A); (iii) prolonged hospitalization (grade B) and bed rest (grade C) is not recommended. Compared with placebo, tocolytics are not associated with a reduction in neonatal mortality or morbidity (LE2) and maternal severe adverse effects may occur with all tocolytics (LE4). Atosiban and nifedipine (grade B), contrary to betamimetics (grade C), can be used for tocolysis in spontaneous preterm labour without preterm premature rupture of membranes. Maintenance tocolysis is not recomended (grade B). Antenatal corticosteroid administration is recommended to every woman at risk of preterm delivery before 34 weeks of gestation (grade A). After 34 weeks, evidences are not consistent enough to recommend systematic antenatal corticosteroid treatment (grade B), however, a course might be indicated in the clinical situations associated with the higher risk of severe respiratory distress syndrome, mainly in case of planned cesarean delivery (grade C). Repeated courses of antenatal corticosteroids are not recommended (grade A). Rescue courses are not recommended (Professional consensus). Magnesium sulfate administration is recommended to women at high risk of imminent preterm birth before 32WG (grade A). Cesarean is not recommended in case of vertex presentation (Professional consensus). Both planned vaginal or elective cesarean delivery is possible in case of breech presentation (Professional consensus). A delayed cord clamping may be considered if the neonatal or maternal state so permits (Professional consensus). CONCLUSION: Except for antenatal corticosteroid and magnesium sulfate administration, diagnostic tools or prenatal pharmacological treatments implemented since 30 years to prevent preterm birth and its consequences have not matched expectations of caregivers and families.