King's College London

Introduction: Stress in pregnancy is associated with adverse outcomes in offspring, and developmental programming is a potential mechanism. We have previously shown that depression in pregnancy is a valid and clearly defined stress paradigm, and both maternal antenatal and offspring stress-related biology is affected. This study aims to clarify whether maternal biology in pregnancy and offspring outcomes can also be influenced by a history of a prior depression, in the absence of depression in pregnancy. Our primary hypothesis is that, similarly to women with depression in pregnancy, women with a history of depression but who are not depressed in pregnancy will have increased cortisol secretion and markers of immune system function, and that their offspring will have poorer neuro-developmental competencies and increased cortisol stress response. Methods: A prospective longitudinal design was used in 59 healthy controls and 25 women with a past history of depression who were not depressed in pregnancy, named as ‘history-only’, and their offspring. Maternal antenatal stress-related biology (cortisol and markers of immune system function) and offspring outcomes (gestational age at birth, neonatal neurobehaviour (Neonatal Behavioural Assessment Scale, NBAS), cortisol stress response and basal cortisol at 2 and 12 months) and cognitive, language and motor development (Bayley Scales of Infant and Toddler Development (BSID)) were measured. Results: Compared with healthy pregnant women, those with a history of depression who remain free of depression in pregnancy exhibit increased markers of immune system function in pregnancy: IL-8 (d = 0.63, p = 0.030), VEGF (d = 0.40, p = 0.008) and MCP-1 (d = 0.61, p = 0.002) and have neonates with lower neurobehavioural scores in most areas, reaching statistical significance in the social-interactive (d = 1.26, p = 0.015) cluster. However, there were no differences in maternal or offspring HPA axis function or in infant development at 12 months. Conclusion: Our study indicates that pregnant women with a history of depression have increased markers of immune system function, and their offspring show behavioural alterations that may be the effects of in utero programming, epigenetic factors or genetic predisposition.