Maternal stress could leave epigenetic imprints on genes in the placenta associated with cortisol — a necessary hormone for foetal development — and this would affect the baby’s development from very early stages, as stated in a paper published in the journal European Neuropsychopharmacology. The study suggests that a mother’s emotional wellbeing during pregnancy is not only important for her, but could also influence the future health of her baby.

The study is led by Lourdes Fañanás, professor at the Faculty of Biology and the Institute of Biomedicine (IBUB) of the University of Barcelona. She is group leader of the Networking Biomedical Research Centre on Mental Health (CIBERSAM) area. The study is also led by Elisabeth Binder, from the Max Planck Institute of Psychiatry in Munich (Germany). The paper includes the collaboration of the Rare Diseases area Networking Biomedical Research Centre (CIBERER) and the experts Elisenda Eixarch and Fátima Crispi, who are also researchers at CIBERER and at the UB’s Faculty of Medicine and Health Sciences, BCNatal (IRSJD and Hospital Clínic - IDIBAPS).

The placenta is an essential organ during pregnancy, as it not only provides oxygen and nutrients to the foetus, but also responds to factors such as maternal stress and helps the foetus adapt to its environment. However, the mechanisms by which the placenta adjusts to these stressors and how it influences foetal development remain largely unexplored.

The research team observed that maternal stress may leave epigenetic marks on certain placental genes. Specifically, these marks do not modify the genetic structure, but they do alter its function. The study identified epigenetic changes in genes related to the regulation of cortisol, an essential hormone in the body’s response to stress.

Supporting women from the very first stages of pregnancy

This pilot study, funded by a CIBERSAM Intramural project, involved 45 healthy, first-time pregnant women. During pregnancy, their cortisol levels and depressive symptoms were measured and, after delivery, placentas were analysed. At seven weeks, the neurodevelopment of the babies was assessed using a specialized test (Brazelton’s NBAS).

The research team used an advanced sequencing technique that allows them to look at epigenetic changes in large areas of DNA and thus gain a very detailed view of the placental response to maternal stress. This method identified changes in key genes involved in cortisol regulation, such as HSD11B2, NR3C1 and FKBP5. The results suggest that maternal stress — especially in early pregnancy — can cause alterations in these genes, which could affect foetal development and the future health of the baby.

Águeda Castro, first author of the study and CIBERSAM researcher at the University of Barcelona, points out that “this study reinforces the importance of taking care of the mental health of mothers from the beginning of pregnancy, since stress could leave a biological imprint on the baby’s development through epigenetic mechanisms that we are just beginning to understand”.

IBUB selected this article as the best scientific publication of November 2024 for its innovative approach to prenatal and mental health. Although this is a pilot study, the results open the door to future research and possible interventions to support pregnant women in vulnerable situations from the earliest stages. While these findings need to be replicated in larger studies, this breakthrough underscores the importance of psychological care and emotional support during pregnancy, not only for the mother's well-being, but also for the long-term health of the baby.