Corticosteroids in the prevention and treatment of infants with bronchopulmonary dysplasia: Part II. Inhaled corticosteroids alone or in combination with surfactants

This paper is the second in a two-part State-of-the-Art series that reviews the latest relevant clinical trials investigating the short-term and long-term effects of corticosteroids in the prevention and treatment of bronchopulmonary dysplasia (BPD). Inhaled postnatal corticosteroids demonstrate low systemic bioavailability and rapid systemic clearance with high pulmonary deposition and were expected to reduce the incidence of BPD with reduced adverse effects, however, increased rate of mortality in the neonatal period and at the 18-24 months follow-up was observed. In a milestone study, intratracheal instillation of corticosteroids combined with surfactant decreased the incidence of BPD without increasing the mortality or the long-term neurodevelopmental adverse outcomes. However, subsequent trials using different types of surfactants, different surfactant to budesonide ratio, different time of the drug administration for infants with different severity of respiratory distress syndrome could not reproduce all the beneficial effects. Future perspectives for the identification of premature infants at high risk of BPD and the prevention or treatment of established BPD are discussed.

Corticosteroids in the prevention and treatment of infants with bronchopulmonary dysplasia: Part I. systemic corticosteroids

Bronchopulmonary dysplasia (BPD) is the most significant respiratory complication of prematurity, and its consequences last from birth into adulthood. Unfortunately, the dramatic improvements in the management of premature infants have not led to a decreased incidence of BPD, or to breakthroughs in treatments offered for this long-lasting chronic respiratory disorder. Over recent decades the pathological picture of BPD has changed from inflammation, interstitial fibrosis and emphysema attributed to volu-, barotrauma and oxygen toxicity to larger, simplified alveoli and dysmorphic vessels related to arrested alveolarization and vasculogenesis with inflammation maintaining a central role. Corticosteroids (CSs) play a key role in the development of respiratory epithelial cells and lung maturation. These potent anti-inflammatory agents have long been used for the prevention and treatment of BPD; however, the risk/benefit ratio of their use remains unresolved. CSs administered antenatally have contributed to reduce mortality and respiratory distress syndrome, no such effect on BPD reduction has been observed. Postnatal systemic CSs reduced the rate and severity of BPD, yet their long-term neurodevelopmental and respiratory consequences markedly limit routine administration. This is the first in a two-part State-of-the-Art series that reviews the latest relevant clinical trials investigating the short-term and long-term effects of CSs in the prevention and treatment of BPD.

SSRIs and SNRIs (SRI) in Pregnancy: Effects on the Course of Pregnancy and the Offspring: How Far Are We from Having All the Answers?

Serotonin has important roles in the development of the brain and other organs. Manipulations of synaptic serotonin by drugs such as serotonin reuptake inhibitors (SRI) or serotonin norepinephrine reuptake inhibitors (SNRI) might alter their development and function. Of interest, most studies on the outcome of prenatal exposure to SRI in human have not found significant embryonic or fetal damage, except for a possible, slight increase in cardiac malformations. In up to a third of newborns exposed to SRI, exposure may induce transient neonatal behavioral changes (poor neonatal adaptation) and increased rate of persistent pulmonary hypertension. Prenatal SRI may also cause slight motor delay and language impairment but these are transient. The data on the possible association of prenatal SRIs with autism spectrum disorder (ASD) are inconsistent, and seem to be related to pre-pregnancy treatment or to maternal depression. Prenatal SRIs also appear to affect the hypothalamic hypophyseal adrenal (HPA) axis inducing epigenetic changes, but the long-term consequences of these effects on humans are as yet unknown. SRIs are metabolized in the liver by several cytochrome P450 (CYP) enzymes. Faster metabolism of most SRIs in late pregnancy leads to lower maternal concentrations, and thus potentially to decreased efficacy which is more prominent in women that are rapid metabolizers. Studies suggest that the serotonin transporter SLC6A4 promoter is associated with adverse neonatal outcomes after SRI exposure. Since maternal depression may adversely affect the child's development, one has to consider the risk of SRI discontinuation on the fetus and the child. As with any drug treatment in pregnancy, the benefits to the mother should be considered versus the possible hazards to the developing embryo/fetus.

The association of pre-pregnancy alcohol drinking with child neuropsychological functioning

OBJECTIVE

To examine the effects of pre-pregnancy alcohol drinking on child neuropsychological functioning.

DESIGN

Prospective follow-up study.

SETTING AND POPULATION

154 women and their children sampled from the Danish National Birth Cohort.

METHODS

Participants were sampled based on maternal alcohol consumption before pregnancy. At 5 years of age, the children were tested with the Wechsler Preschool and Primary Scale of Intelligence-Revised, the Test of Everyday Attention for Children at Five (TEACh-5), and the Movement Assessment Battery for Children (MABC). The Behaviour Rating Inventory of Executive Function (BRIEF) was completed by the mothers and a preschool teacher. Parental education, maternal IQ, prenatal maternal smoking, child's age at testing, child's sex, and maternal alcohol intake during pregnancy were considered potential confounders.

MAIN OUTCOME MEASURES

Performance on the Wechsler Preschool and Primary Scale of Intelligence-Revised, the TEACh-5, the MABC, and the BRIEF.

RESULTS

Intake of 15-21 drinks/week on average prior to pregnancy was not associated with any of the outcomes, but intake of ≥22 drinks/week on average was associated with a significantly lower adjusted mean full scale IQ and lower adjusted means in overall attention and sustained attention score, but not in selective attention score or any of the BRIEF index scores or MABC scores.

CONCLUSIONS

Intake of ≥22 drinks/week before pregnancy was associated with lower mean full scale IQ, overall attention and sustained attention. Assessment of pre-pregnancy drinking provides additional information regarding potential prenatal alcohol exposure and its implications for child neurodevelopment.

The effects of low to moderate alcohol consumption and binge drinking in early pregnancy on behaviour in 5-year-old children: a prospective cohort study on 1628 children

OBJECTIVE

To examine the effects of low to moderate maternal alcohol consumption and binge drinking in early pregnancy on behaviour in children at the age of 5 years.

DESIGN

Prospective cohort study.

SETTING

Neuropsychological testing in four Danish cities, 2003-2008.

POPULATION

A total of 1628 women and their children sampled from the Danish National Birth Cohort.

METHODS

Participants were sampled based on maternal alcohol drinking patterns during early pregnancy. When the children were 5 years of age the parent and teacher versions of the Strengths and Difficulties Questionnaire (SDQ) were completed by the mothers and a preschool teacher, respectively. The full statistical model included the following potential confounding factors: maternal binge drinking or low to moderate alcohol consumption, respectively; parental education; maternal IQ; prenatal maternal smoking; the child's age at testing; the child's gender; maternal age; parity; maternal marital status; family home environment; postnatal parental smoking; prepregnancy maternal body mass index (BMI); and the child's health status.

MAIN OUTCOME MEASURE

Behaviour among children assessed by the SDQ parent and teacher forms.

RESULTS

Adjusted for all potential confounding factors, no statistically significant associations were observed between maternal low to moderate average weekly alcohol consumption and SDQ behavioural scores (OR 1.1, 95% CI 0.5-2.3; OR 1.1, 95% CI 0.6-2.1 for the total difficulties scores) or between binge drinking and SDQ behavioural scores (OR 1.2, 95% CI 0.8-1.7; OR 0.8, 95% CI 0.6-1.2).

CONCLUSION

This study observed no consistent effects of low to moderate alcohol consumption or binge drinking in early pregnancy on offspring behaviour at the age of 5 years.

The effects of low to moderate prenatal alcohol exposure in early pregnancy on IQ in 5-year-old children

OBJECTIVE

To examine the effects of low to moderate maternal alcohol consumption during early pregnancy on children's intelligence (IQ) at age 5 years.

DESIGN

Prospective follow-up study.

SETTING

Neuropsychological testing in four Danish cities 2003-2008.

POPULATION

A cohort of 1628 women and their children sampled from the Danish National Birth Cohort.

METHODS

Participants were sampled based on maternal alcohol consumption during pregnancy. At 5 years of age, children were tested with the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R). Parental education, maternal IQ, maternal smoking in pregnancy, the child's age at testing, gender, and tester were considered core confounding factors, whereas the full model also controlled for maternal binge drinking, age, BMI, parity, home environment, postnatal smoking in the home, health status, and indicators for hearing and vision impairments.

MAIN OUTCOME MEASURES

The WPPSI-R.

RESULTS

No differences in test performance were observed between children whose mothers reported consuming between one and four or between five and eight drinks per week at some point during pregnancy, compared with children of mothers who abstained. For women who reported consuming nine or more drinks per week no differences were observed for mean differences; however, the risks of low full-scale IQ (OR 4.6; 95% CI 1.2-18.2) and low verbal IQ (OR 5.9; 95% CI 1.4-24.9) scores, but not low performance IQ score, were increased.

CONCLUSIONS

Maternal consumption of low to moderate quantities of alcohol during pregnancy was not associated with the mean IQ score of preschool children. Despite these findings, acceptable levels of alcohol use during pregnancy have not yet been established, and conservative advice for women continues to be to avoid alcohol use during pregnancy.

Discriminating the effects of prenatal alcohol exposure from other behavioral and learning disorders

Fetal alcohol syndrome and fetal alcohol spectrum disorders are underdiagnosed in general treatment settings. Among the factors involved in identifying the effects of prenatal alcohol exposure are (1) the evidence for prenatal alcohol exposure; (2) the effects of the postnatal, caregiving environment; (3) comorbidities; and (4) differential diagnosis, which includes identifying the neurodevelopmental effects of alcohol and discriminating these effects from those characterizing other conditions. This article reviews findings on the neurodevelopmental effects of prenatal alcohol exposure, including learning and memory, motor and sensory/motor effects, visual/spatial skills, and executive functioning and effortful control. Encouraging clinicians to discriminate the effects of prenatal alcohol exposure from other conditions may require more education and training but ultimately will improve outcomes for affected children.

Dose-response relationship of prenatal mercury exposure and IQ: an integrative analysis of epidemiologic data

BACKGROUND

Prenatal exposure to mercury has been associated with adverse childhood neurologic outcomes in epidemiologic studies. Dose-response information for this relationship is useful for estimating benefits of reduced mercury exposure.

OBJECTIVES

We estimated a dose-response relationship between maternal mercury body burden and subsequent childhood decrements in intelligence quotient (IQ), using a Bayesian hierarchical model to integrate data from three epidemiologic studies.

METHODS

Inputs to the model consist of dose-response coefficients from studies conducted in the Faroe Islands, New Zealand, and the Seychelles Islands. IQ coefficients were available from previous work for the latter two studies, and a coefficient for the Faroe Islands study was estimated from three IQ subtests. Other tests of cognition/achievement were included in the hierarchical model to obtain more accurate estimates of study-to-study and end point-to-end point variability.

RESULTS

We find a central estimate of -0.18 IQ points (95% confidence interval, -0.378 to -0.009) for each parts per million increase of maternal hair mercury, similar to the estimates for both the Faroe Islands and Seychelles studies, and lower in magnitude than the estimate for the New Zealand study. Sensitivity analyses produce similar results, with the IQ coefficient central estimate ranging from -0.13 to -0.25.

CONCLUSIONS

IQ is a useful end point for estimating neurodevelopmental effects, but may not fully represent cognitive deficits associated with mercury exposure, and does not represent deficits related to attention and motor skills. Nevertheless, the integrated IQ coefficient provides a more robust description of the dose-response relationship for prenatal mercury exposure and cognitive functioning than results of any single study.