Maternal Mental Health Trial

Inclusion Criteria: * Singleton pregnant * Prior history of perinatal depression * Age between 18 and 45 years Exclusion Criteria: * Moderate to severe depression with onset during pregnancy * Severe psychiatric disorders (e.g. disorders with psychotic symptoms, schizophrenia, bipolar disorders, inpatient eating disorders and inpatient obsessive-compulsive disorders) * Previous suicide attempts without having a depressive episode * Prior history or ongoing neurological disorders (e.g. migraine or epilepsy) * Severe somatic illness * Prior history or ongoing cancer * Prior history of venous thromboembolism, myocardial infarction, cerebrovascular thromboembolism or thrombophilia, or other risk factors clinically assessed after thrombophilia screening * Deep vein thrombosis or pulmonary embolism in current pregnancy * Pregnancy-induced hypertension or preeclampsia * Pre-existing atherosclerosis or well-known cardiovascular risk factors (e.g. diabetes, hypertension) * Other contraindication for oestrogen treatment (e.g. acute liver failure, severe varicose veins) * Use of psychotropic pharmacology, except for short-term sleep support treatment * Non-fluent in Danish or pronounced vision or hearing loss * Body Mass Index (BMI) \>35 kg/m2 * Ongoing alcohol or drug abuse * Severe postpartum haemorrhage (\>1500 ml) * Severe illness in the infant or perinatal death