Presented at the Neonatal Society 2003 Summer Meeting.
Morrell J2, Andrews DC1, Murray L2, Cooper P2, Johnson P1
1 Nuffield Department of Obstetrics & Gynaecology, John Radcliffe Hospital, Oxford, UK
2 Winnicott Research Unit, Dept of Psychology, University of Reading, UK.
Background: Conditions of socio-economic disadvantage and markers of stress (e.g. smoking, anxiety) are believed to impact on biophysiological development. Furthermore, infants from populations with such adversity form the majority of cases of Sudden Infant Death Syndrome (SIDS). The objective of this study was to investigated the interaction between psychosocial status and biophysiological development. The effects on growth are reported here.
Methods: Low (LR, 64) and high (HR, 58) risk primiparous mothers were recruited into the study grouped by an index of social adversity, risk for depression and lifestyle factors associated with SIDS. Growth was measured at 28, 34 weeks GA, at birth (weight only) and at 10days, 4, 7, & 12 weeks postnatally. Repeated foetal and infant growth outcomes were analysed using multilevel modelling to examine the effects of risk status, SIDS factors, adversity factors and depression risk factors at each time point, in addition to parenting at postnatal time points on growth outcomes (controlling for relevant covariates such as gender, maternal height, maternal weight, and breast vs bottle feeding).
Results: Growth in weight was lower in the high risk group, despite the fact that breast feeding (only practiced in the low risk group) was associated with lower growth rates at 10 days and 4 weeks. Relevant explanatory variables for the effect of high risk were; low maternal education, high anxiety during pregnancy, and poor parenting on postnatal growth. Smoking during pregnancy was associated with lower growth in weight, but this effect disappeared when the other explanatory variables above were included in the model. Growth in head circumference was lower in the high risk group. Relevant explanatory variables for the effect of high risk were; anxiety during pregnancy, living in a disordered/chaotic environment, and for postnatal growth depression at 4 weeks and a remote/distant style of mother-infant parenting interaction. Smoking in pregnancy had a bimodal effect on growth in head circumference, being associated with lower growth rates with exposure at 28 weeks and higher growth rates with exposure at 34 weeks. Again these effects disappeared when the above explanatory variables were entered into the model. As reported before, the other anthropometric measurements made (chest, abdomen, arm, crown rump, and crown heel) were not consistently different by risk status.
Conclusions: Maternal psychosocial adversity and parenting had a significant impact on foetal/infant and postnatal growth respectively. This selective effect on head size (as opposed to other anthropomorphic measurements) persisted into postnatal life and differs to the expected pattern of growth restriction. In this regard, a picture emerges from our data of the influence of high anxiety during pregnancy and associated poor parenting that appears to account for the effects of high risk status on growth. These findings have clear implications for the need for improved psychosocial support of mothers at high risk.