Red flags — call us immediately or go to the Emergency Department if:
- Your baby is unusually drowsy or hard to rouse for feeds (infant sedation)
- Your baby is feeding much less than usual or losing weight
- You notice changes in your mood, thinking, or sleep that worry you (contact your mental health team)
- You feel thoughts of hurting yourself or your baby (call 112 immediately)
- You stopped quetiapine suddenly and feel very unwell
- A rash that does NOT fade when you press a clear glass on it — sepsis sign
- Fever in a baby under 3 months (any temperature ≥ 38.0 °C)
- Fast breathing, blue lips, or sucking-in of the ribs — breathing emergency
- A fit/seizure, or your child becomes floppy or unresponsive — general red flag
What quetiapine is
Quetiapine (Seroquel) is an atypical antipsychotic. Doctors prescribe it for bipolar disorder, schizophrenia, and sometimes for depression or severe anxiety. In the postpartum period it is particularly important for mothers with bipolar disorder or a history of psychosis, where stopping the medicine carries serious risks.
How much passes into breast milk
Studies show that quetiapine passes into breast milk in very small amounts. The relative infant dose — the estimated amount the baby gets per kg of body weight as a percentage of the mother's dose — is generally under 1 % in most published studies. This is very low. For healthy, full-term babies, specialist sources generally classify quetiapine as compatible with breastfeeding with monitoring.
What current guidance says
LactMed classifies quetiapine as generally compatible with breastfeeding, noting the low relative infant dose and limited reports of adverse effects in breastfed infants. The UK Drugs in Breastmilk Information Service and Hale's Medications and Mothers' Milk concur. The Belgian AFMPS SmPC advises caution but does not prohibit breastfeeding. Your psychiatrist or prescribing doctor weighed these risks when deciding your treatment.
What to watch for in your baby
Most breastfed babies of mothers taking quetiapine show no effects. Watch for unusual drowsiness, feeding difficulties, or slower weight gain. If these appear, contact your GP or paediatrician. Premature babies or very young newborns need extra monitoring.
Your mental health is the priority
Quetiapine is often prescribed because the risks of stopping it are high — especially for bipolar disorder, where postpartum relapse can be rapid and severe. Never stop quetiapine without talking to your psychiatrist or prescribing doctor first. Your mental health stability is essential for both your wellbeing and safe parenting.
If anything changes
Watch your baby for unusual drowsiness or poor feeding. Never stop quetiapine without your doctor's guidance — relapse risk is real. If you ever have thoughts of harming yourself or your baby, call 112 immediately.
Emergency? Call 112. Do not wait for a reply from us.
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Message us on WhatsAppReviewed and signed off by Dr Didier Decamps on 5 September 2026. This is general information and does not replace an individual assessment by a qualified clinician.
Written with AI assistance. Reviewed, corrected and signed by Dr Didier Decamps, paediatrician.
Last reviewed: 5 September 2026