The aim of this study is to assess a mindfulness and compassion group intervention for pregnant women and their partners (8 weeks) for the prevention, reduction and treatment of stress, negative affect and depression in pregnancy and breastfeeding. This group intervention will also be compared with a Treatment as usual (TAU) group consisting in a childbirth education class taught by the Health Center midwife. The principal hypothesis is that the mindfulness and compassion intervention will be more effective than TAU.