Effects of Maternal Cortisol during Pregnancy on Children's Blood Pressure Responses

Background: It is well established that birth weight has an effect on subsequent blood pressure. Predominantly experimental studies have also reported effects of altered corticosteroid levels on subsequent cardiovascular responses. In the current study, we have examined the effects of both birth weight and maternal cortisol levels in a cohort of mothers and their pre-adolescent children. Procedure: A total of 216 women and their 7- to 9-year-old children comprised the cohort. The women had been assessed for plasma cortisol during the first (n = 71), second (n = 72) and third (n = 73) trimester. Maternal cortisol had been measured on a fasting sample taken between 9 and 11 a.m. The children's blood pressure and heart rate were recorded in the resting state, in response to a 10-min video game stress challenge and during recovery. Resting values, incremental responses to stress and recovery were evaluated. Observation: Maternal cortisol levels increased with duration of pregnancy. There were inverse correlations between birth weight and all haemodynamic measures. The positive associations between maternal cortisol and children's haemodynamic measures were most evident in the first and second trimesters. Birth weight was inversely related to maternal cortisol. In multiple regression analyses, the effects of maternal cortisol were more consistent than those of birth weight. Conclusion: Both birth weight and maternal cortisol are predictive of children's resting and stress-modulated haemodynamic measures. The effects of birth weight may partly mediate the effects of maternal cortisol.