Untreated psychiatric disorder is associated with a range of adverse fetal outcomes, including intra-uterine growth restriction and prematurity. The safety of the patient, other members of the public, including any accompanying children, and staff is the paramount consideration. A mental state examination, even if relatively brief, is a core component of any assessment of a psychiatric emergency. Suicide risk is by far the more likely risk in a psychiatric emergency presenting in pregnancy. If the patient should become very angry and aroused but she does not present an immediate danger, deescalation may be attempted. The key principle of emergency restraint that applies to the pregnant patient is the avoidance of vena cava syndrome. The emergency use of a short-acting benzodiazepine, such as intramuscular lorazepam, is not contraindicated in a pregnant woman who requires rapid tranquillisation for her own safety and the safety of others.