The correlation between stress response term babies with intrauterine growth restriction and adulthood disease theories.

BACKGROUND

Every year, 14 million babies are born with low birth weight (LBW) and/or intrauterine growth restriction (IUGR) in developing countries. In Sudan, 15-25% of all newborns are born with LBW, with half being Term-LBW. The importance of nutrition in the first 1000 days of life has been well demonstrated. Evidence links IUGR to various health and developmental disorders, and intrauterine programming of the hypothalamic-pituitary-adrenal (HPA) axis has been strongly suggested as a possible mechanism. Sudan has been listed among the lowest four countries regarding food security which has a massive impact on maternal and infant health.

HYPOTHESIS: We hypothesize that infants who suffer from intrauterine growth retardation will have exaggerated physiological and behavioural responses to physical stressors.

OBJECTIVES

To compare T-LBW with T-NBW on (a) Salivary cortisol level at rest and after a physical stressor and (b) Behavioural response to physical stressors.

METHODS

Hospital-based matched case-control study. Cases were 65 T-LBW neonates, and controls were 67 T-NBW neonates matched for age 4-6 hours, gestational age, and mode of deliverymeasurements: Anthropometry, salivary samples for cortisol before and after heel prick, and behavioural ratings.

RESULTS

Compared with controls, the IUGR neonates were lighter, shorter, and thinner (p <0.0001) and had lower basal cortisol levels (p <0.03). Following stressors, IUGR neonates had lower (p >0.0001) and inhibited cortisol response (p <0.02), and cried less vigorously (p <0.0001). All anthropometric measures were significantly and positively correlated with behavioural responses and pre- and post-stress cortisol levels. Stunting was more strongly associated with behavioural inhibition than wasting.

CONCLUSION

The severity of intrauterine growth retardation correlated with behavioral and physiological inhibition, which can lead to the development of mismatch diseases such as allergies, autoimmune diseases, and conjunctive disorders.