Red flags — call us immediately or go to the Emergency Department if:
- Excessive sleepiness — very hard to wake for feeds, sleeping through feeds
- Refusing two or more feeds in a row, or feeding very weakly
- Weight not gaining, or losing weight
- Unusual stiffness, tremors, or abnormal writhing movements
- Fever above 38 °C if under 3 months old
- Non-blanching rash (spots that do not fade when pressed)
- Any breathing difficulty — fast breathing, grunting, or ribs pulling in
- Floppiness, seizure, or unresponsiveness
What this is
Antipsychotic medicines treat serious mental health conditions including schizophrenia and bipolar disorder. The most commonly used ones in Belgium include olanzapine (Zyprexa), quetiapine (Seroquel), risperidone (Risperdal), aripiprazole (Abilify), and haloperidol. Most of these can be used while breastfeeding under specialist supervision, with monitoring of your baby. Clozapine (Leponex) is the exception — it is generally not recommended during breastfeeding because of a small risk of serious blood-cell effects in the baby.
Olanzapine and quetiapine — often used in breastfeeding
Olanzapine and quetiapine pass into breast milk in small amounts. Studies of breastfed babies of mothers on these medicines have not found serious problems at normal doses, though some babies are slightly sleepier than usual. Most specialist perinatal psychiatry teams in Belgium and across Europe support breastfeeding on these medicines, provided the baby is monitored for sedation and weight gain. Haloperidol also has a long record of use in breastfeeding.
The most important thing: do not stop your medicine
Stopping an antipsychotic suddenly is very dangerous. The postpartum period is already a very high-risk time for psychiatric relapse. A relapse can put both you and your baby at risk. If you are worried about breastfeeding, please speak to your psychiatrist — they may be able to adjust the dose or the timing, or reassure you about the specific medicine you are taking. Never reduce or stop on your own.
What to watch for in your baby
The main things to watch for are: your baby being much sleepier than usual, feeding poorly, not gaining weight, or showing unusual movements (stiffness, tremor, or writhing). These effects are not common, but they are important to catch early. Your paediatrician or midwife should weigh your baby regularly in the first weeks.
Keep all appointments and ask for a monitoring plan
If you are on an antipsychotic and breastfeeding, ask your psychiatrist and paediatrician to put a simple monitoring plan in place. This usually means weighing your baby regularly and watching for the signs above. You do not usually need blood tests for the baby unless clozapine is involved. Every baby needs 400 IU (10 µg) of vitamin D a day from birth, breastfed or formula-fed. Continue through childhood; ask us how long.
If anything changes
Call us if your baby is very difficult to wake, won't feed, is unusually stiff, or you are worried in any way — or contact your psychiatrist immediately if your own symptoms change.
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 21 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: 21 September 2026