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Stem
Mrs R, a 32-year-old primigravida, is brought to the emergency department by her husband on day 6 after an uncomplicated vaginal delivery at term. He describes three nights during which she has not slept despite being exhausted, increasing talk of "the baby not being mine," whispering to people who are not there, and a rapidly shifting mood from tearful withdrawal to restless over-activity. This morning she tried to leave the house in sub-zero temperatures with the baby wearing only a vest. She has one previous brief depressive episode five years ago and her mother has bipolar I disorder. There is no history of substance use or physical illness. She is afebrile, pulse 96, blood pressure 118/72, and physical examination is normal. She breastfed her first feed in hospital but has not fed the baby today.
Questions
a) What is the most likely diagnosis, what clinical features support it, and why is it an emergency? (2 marks)
The most likely diagnosis is postpartum (puerperal) psychosis. The supporting features are: onset within 2 weeks of delivery (here day 6, in the classic window of days 3 to 10); the cardinal prodrome of insomnia despite exhaustion; delusional misidentification of the infant (the belief that "the baby is not mine"); auditory hallucinations; rapidly shifting mood (mixed affective-psychotic picture); a personal history of mood disorder and a family history of bipolar disorder, the single strongest risk factor for postpartum psychosis after a previous episode.
It is a psychiatric emergency because of the dual risk of maternal suicide — a leading cause of direct maternal death within the first postpartum year (MBRRACE-UK) — and infanticide, which classically occurs in the context of delusional beliefs about the infant (here, the false belief that the baby is not hers and the unsafe behaviour in sub-zero temperatures). The illness evolves over hours to days and so demands an immediate, structured response. (1 mark for the diagnosis with at least four supporting features, 1 mark for naming the dual risk of suicide and infanticide and the emergency nature.)
b) Outline your immediate assessment and the investigations you would arrange. (3 marks)
- Risk assessment — direct, structured enquiry about thoughts of harming herself or the infant (item-10 style enquiry), intent, access to means, and any preparatory acts; collateral from the husband.
- Mental state examination — appearance (restless, perplexed), speech (rapidity, flight of ideas), mood (labile), thought (delusional misidentification, persecutory beliefs), perception (auditory hallucinations), cognition (orientation, attention — exclude delirium), insight (typically impaired).
- Safeguarding — the infant must be under constant supervision and not alone with the mother while she is acutely unwell; involve the partner and, where indicated, safeguarding / social care.
- Collateral and history — obstetric history, personal and family psychiatric history (bipolar), medications, substance use, recent infections, thyroid status.
- Investigations — full blood count, urea and electrolytes, liver function, thyroid function (to exclude postpartum thyroiditis), C-reactive protein and blood glucose, calcium, vitamin B12 and folate, a urine drug screen and a beta-hCG if not postpartum, and an infection screen. The aim is to exclude delirium and an organic contributor before confirming a functional psychiatric diagnosis. (1 mark for risk assessment including self and infant; 1 mark for mental state and safeguarding of the infant; 1 mark for the investigation panel aimed at excluding organic causes.)
c) Describe your immediate and definitive management, including pharmacological choices and the principles of breastfeeding in this context. (3 marks)
Immediate: urgent psychiatric admission, ideally to a specialist mother-and-baby unit (MBU) so that the mother-infant bond is preserved while the infant is safeguarded. She should be under one-to-one observation initially; ligature points and means removed; transfer arranged under mental-health legislation if she lacks capacity or refuses (the duty of care overrides autonomous refusal when risk is imminent).
Pharmacological: an antipsychotic is first-line — options include olanzapine, haloperidol, risperidone or quetiapine. A short-acting benzodiazepine (lorazepam) is useful for the acute agitation and to restore sleep, and is safe in the short term. SSRIs as monotherapy are inappropriate in this mixed affective-psychotic picture and may precipitate a switch to mania. ECT is indicated if the illness is severe, life-threatening (catatonia, refusal of food and fluids, active suicidality) or treatment-resistant. Once the acute episode is settling, lithium is the most effective long-term mood stabiliser for the prevention of further bipolar / puerperal episodes, started cautiously once the baby is settled and with monitoring of serum levels and thyroid and renal function.
Breastfeeding: this is a clinical decision weighing the benefits of continued breastfeeding against drug exposure. Haloperidol and olanzapine have comparatively good lactation safety data; if the mother is too unwell to feed, milk may be expressed and discarded until the medication is stabilised. Where an SSRI is later needed for depression in a breastfeeding mother, sertraline is the SSRI of choice (lowest relative infant dose); lithium is generally avoided in breastfeeding. (1 mark for admission to MBU and safeguarding; 1 mark for antipsychotic plus benzodiazepine and the role of ECT and lithium; 1 mark for a balanced approach to breastfeeding with named agents.)
d) What is Mrs R's risk of recurrence in a future pregnancy, and what perinatal plan would you recommend? (2 marks)
Her recurrence risk in a future pregnancy is high — around 50 percent in women with a personal history of postpartum psychosis, and even higher in those who also have bipolar disorder.
The plan, made preconception with a specialist perinatal psychiatrist: contraception until she is well and stable; review of mood-stabiliser strategy (continue or switch to a safer agent in pregnancy, with the explicit understanding that prophylactic medication through pregnancy reduces postpartum relapse from about 66 percent to about 23 percent in bipolar women); planned delivery with peripartum medication adjustment (for example, lithium dose titration and careful hydration around delivery); prophylactic medication commenced immediately postpartum; intensive monitoring for the first 2 to 4 weeks postpartum, when most episodes begin; and a written perinatal mental-health plan shared with the woman, her partner, the obstetric team, the GP, the health visitor and the perinatal mental-health team. (1 mark for the approximate 50 percent recurrence figure with rationale; 1 mark for a structured preconception-to-postpartum plan with named prophylactic strategy and intensive monitoring.)