Maternal smoking and low birthweight: implications for antenatal care

Socioeconomic differences in children's health: how and why do these relationships change with age?

The effects of socioeconomic status (SES) on health are well documented in adulthood, but far less is known about its effects in childhood. The authors reviewed the literature and found support for a childhood SES effect, whereby each decrease in SES was associated with an increased health risk. The authors explored how this relationship changed as children underwent normal developmental changes and proposed 3 models to describe the temporal patterns. The authors found that a model's capacity to explain SES-health relationships varied across health outcomes. Childhood injury showed stronger relationships with SES at younger ages, whereas smoking showed stronger relationships with SES in adolescence. Finally, the authors proposed a developmental approach to exploring mechanisms that link SES and child health.

Psychosocial predictors of labor/delivery complications and infant birth weight: a prospective multivariate study

Using a multidimensional approach to measure stress, this study prospectively examined the influence of maternal stress, social support and coping styles on labor/delivery complications and infant birth weight. Beginning in the third month of pregnancy, stress was assessed monthly. In each trimester, data on social support, coping strategies, lifestyle behaviors and pregnancy progress were collected. One month following delivery, information on labor, delivery and infant status was obtained. The final sample consisted of 80 women. The results demonstrated that women who experienced greater stress during pregnancy had a more difficult labor/delivery, even after controlling for parity. Younger maternal age was also linked with intrapartum complications. Perceived prenatal social support emerged as a predictor of infant birth weight. Women who reported less satisfaction with their social support in the second trimester gave birth to infants of lower birth weight. The results suggest an association between specific psychosocial variables and negative birth outcomes.

Pulmonary function in children with initial low birth weight

The objective of this analysis was to examine the effect of low birth weight and prematurity on bronchial air-flow, bronchial reactivity, airway symptoms and asthma diagnosis at school age. A cross-sectional epidemiological study was performed in three small towns in the eastern part of Germany on 2470 school children aged 5-14 (89.1% of eligible children). A 78 item questionnaire to determine risk factors at birth and in early childhood was employed. 7.8% of the children were born before completing 38 gestational weeks; 6.6% had a birth weight less than 2500 g. Pulmonary function analysis were done by a mobile plethysmography at the school. There were only weak restrictions in lung volume in term low birth weight (LBW) children (100 ml lower TLC, p = 0.107), and flow (257 ml lower PEFR, p = 0.108), were low. However, bronchial hyper-responsiveness indicated by 292 ml lower FEV1.0 after cold air bronchial provocation, was significantly increased compared to term normal birth weight children (p < 0.001). The effect of LBW was less in older children, only slightly stronger in girls and increased in children mechanically ventilated during the postnatal period. Correspondingly, there was a higher prevalence of diagnosed asthma in term LBW children (OR 1.6, 95%-confidence interval 1.0-2.6), however these were without an increased risk for any allergic sensitization. LBW, therefore, seems to be a risk factor for smaller lungs and hyperreactive airways primarily in term born children, whereas in preterm children the immature bronchial system seems to be recover by school age.

Effect of changes in maternal smoking habits in early pregnancy on infant birthweight

BACKGROUND

The inverse relationship between maternal smoking and infant birthweight is well documented.

AIM

The aim of the present study was to examine whether a change in maternal cigarette consumption in early pregnancy affects the infant's birthweight.

METHOD

A total of 5980 women who presented to their general practitioners between 1976 and 1979 with an unplanned pregnancy and the babies resulting from these pregnancies were included in the study. Women were divided into four categories: non-smokers, smokers, quitters and reducers.

RESULTS

In terms of mean infant birthweight, the non-smokers had a clear benefit over the smokers whose babies were 153 g lighter (P < 0.001), and over the quitters whose infants were 39 g lighter. There was also an advantage in stopping smoking: the smokers had babies whose mean birthweight was 120 g less than that of the quitters (P < 0.001). There was no demonstrable benefit from reducing cigarette consumption without entirely stopping.

CONCLUSION

These findings may have important implications for where best to target health education.

Mild prematurity and respiratory functions

Pulmonary function tests and bronchial reactivity to methacholine (MCH) were measured in 34 randomly selected prematures (21 males, 13 females; mean age 11.6 years; mean gestational age 34.9 weeks; mean birth weight 1980 g) and in 34 siblings (22 males, 12 females; mean age 12.5 years, mean gestational age 39.5 weeks; mean birth weight 3030 g). None had suffered neonatal respiratory distress syndrome or had been artificially ventilated. Prematurely born children had a residual volume (RV) and residual volume/total lung capacity (RV/TLC) significantly (P < 0.01) increased compared to controls, although the mean values of both groups were still within the upper limits of normal. Furthermore, an increase of closing volume/vital capacity and closing capacity/total lung capacity (CC/TLC) was observed in most patients with increased RV and RV/TLC. No significant difference was observed for bronchial responsiveness to MCH between prematurely born and control children (11.8% and 5.9% of hyperreactive subjects, respectively). Maternal smoking during pregnancy was prevalent in prematures with impaired respiratory functions. In conclusion clinically normal children of smoking mothers who have survived prematurity but present some respiratory function impairment compared to their born-at-term siblings, should be fully informed and protected from risk factors for chronic obstructive pulmonary disease (COPD) in adult life.

Mental retardation associated with parental smoking and alcohol consumption before, during, and after pregnancy

METHODS

In an epidemiologic study, parental alcohol consumption and smoking before, during, and after pregnancy were studied as possible risk factors for mental retardation in offspring. The parents of 306 mentally retarded children (cases) and 322 physically handicapped children (referents) were interviewed about their lifestyle habits from 3 months preconception to 6 months postnatal.

RESULTS

Odds ratios with 95% confidence intervals were calculated as risk indicators. For fathers who smoked a pipe or cigars, an odds ratio of 2.4 (95% CI: 1.2-5.1) was observed. Maternal alcohol consumption was increased among the case mothers with risk ratios ranging from 1.7 (95% CI: 1.2-2.3) preconception to 1.4 (95% CI:1.0-2.0) during the fetal period. These risks were more pronounced for the mothers who consumed greater than or equal to 3 drinks/day once or twice a week.

CONCLUSIONS

This study suggests that paternal smoking and maternal alcohol consumption are risk factors for mental retardation in offspring.

Inequalities in pregnancy outcome: a review of psychosocial and behavioural mediators

The purpose of this paper is to review the literature on psychosocial factors in pregnancy outcome and to present a model which attempts to integrate the findings theoretically. There are four sections. The first presents published data on the incidence of early childhood mortality and low birth weight. Changes over time and differences between countries are noted and attention is drawn to the marked inequalities between occupational groups in the British data. The second section reviews the evidence that a variety of psychosocial risk factors influence pregnancy outcome, notably social, emotional, cognitive and behavioural factors. The third section develops the theme of inequalities and examines theories which have been advanced to account for the differences in adult mortality. We argue that material deprivation goes some way towards explaining inequalities in pregnancy outcome, but that any proper account will have to explain the links between inputs and outcomes--the processes and mechanisms by which material deprivation is translated into observable mortality and morbidity. In the concluding section, we argue that some of the principal links are the psychosocial risk factors described in the second section, and we present a model which traces the pathways of mediation.

Lung function in children of low birth weight

Lung function was recorded in a cohort of 130 age specific children of low birth weight (under 2000 g) and a reference population of 120 unselected local schoolchildren at 7 years of age. Children of the cohort were similar in height and forced vital capacity to the reference group, but had significantly reduced forced expiratory volume in 0.75 second and expiratory flow indices. Although neonatal respiratory illness was associated with reduced airway function, we were unable to confirm that this was a consequence of oxygen treatment or mechanical ventilation. Low birth weight, however, was closely associated with poor airway function independent of neonatal respiratory illness. Other factors of importance included the male gender and maternal smoking. The reduction in airway function observed in the low birthweight children was associated with cough but not wheeze. The disparity between the relatively well preserved vital capacity and reduced airway function suggests that very low birth weight, and hence prematurity, has its greatest effect on the subsequent growth of airway function. The absence of an association between neonatal oxygen score or mechanical ventilation and childhood lung function suggests that the long term effect of neonatal respiratory treatment is small compared with that of birth weight, maternal smoking, and male sex.

Respiratory symptoms in children of low birth weight

We recorded the respiratory history by questionnaire in a 7 year old cohort of children whose birth weight was under 2000 g and an unselected reference group of local schoolchildren of the same age. Complete data were obtained in 121 low birthweight children (90% of those studied): 62 who had no neonatal respiratory illness, 25 who had oxygen treatment only, and 34 who received mechanical ventilation (of whom 10 had bronchopulmonary dysplasia). The low birthweight children were no more likely to wheeze than the reference group, but frequent and troublesome cough was significantly more common, especially among children of very low birth weight (under 1500 g) who had received neonatal respiratory treatment. Neonatal mechanical ventilation was not associated with increased symptoms when compared with neonatal oxygen treatment alone. The prevalence of cough at the age of 7 was independently associated with the level of neonatal intensive care as defined by oxygen score. Although there was no excess of wheeze in the cohort compared with the reference group, there was a weak correlation between wheeze and the neonatal oxygen score as well as with maternal smoking. Loss of schooling due to respiratory symptoms in the nine months before this study was no greater in children of low birth weight than in the reference group.