Red flags — call us immediately or go to the Emergency Department if:
- Unusual sleepiness — very difficult to wake (opioid/CNS sedation) — call 112 immediately
- Breathing that is slow, shallow, or irregular — call 112 immediately
- Seizure or shaking fits (cocaine / stimulant toxicity) — call 112 immediately
- Limpness, poor muscle tone, or no reaction when you try to rouse them — call 112 immediately
- Rapid heart rate, severe irritability, or jitteriness in the baby (stimulants / cocaine)
- Your baby is in the care of someone who is acutely intoxicated — call 112 for safeguarding support
- Fast breathing, blue lips, or sucking-in of the ribs — breathing emergency
- A rash that does NOT fade when you press a clear glass on it — sepsis sign
What this is
Reaching out like this takes courage, and it tells me how much you care about your baby. Different substances have different levels of risk for a breastfed baby. Some are compatible with breastfeeding — especially when used in a stable, medically supervised way. Others are not safe at any level. I will give you accurate information so you can make the safest choices.
Methadone and buprenorphine (opioid maintenance therapy)
If you are on a stable methadone or buprenorphine programme under medical supervision, breastfeeding is generally encouraged. The amount that passes into your milk is small, and breastfeeding actually helps reduce withdrawal symptoms in your baby (a condition called neonatal opioid withdrawal syndrome). Keep your dose stable — do not increase or decrease without talking to your doctor. If your dose has recently gone up, or if you are using other substances on top, watch your baby closely for unusual sleepiness. Do not breastfeed if you are acutely intoxicated.
Cannabis (THC)
THC passes into breast milk and concentrates there because it is fat-soluble. Infant brains have many receptors sensitive to THC at this age. The evidence does not support breastfeeding if you are using cannabis regularly. There is no proven safe level, and THC can stay in milk for several days after a single use. If you have used cannabis, do not stop breastfeeding abruptly — talk to us about the safest plan. Reducing use as much as possible is the safest path.
Cocaine, heroin, MDMA, amphetamines
These substances transfer into breast milk and can cause serious harm to your baby — irritability, seizure, or dangerous sedation. If you have used any of these in the last 24 hours, do not breastfeed. Express your milk and discard it to keep your supply going. When you are ready to talk about support services, we are here to help — no judgement, only support. Your baby still benefits enormously from your care and presence.
Polydrug use and alcohol
Using more than one substance at a time — for example, cannabis and alcohol, or opioids and benzodiazepines — greatly increases the risk for your baby. The effects in breast milk combine. If this applies to you, please speak to your GP or addiction support service today. You will not be judged. You will be helped.
Keeping your baby safe
If you ever feel too drowsy or unwell to care for your baby safely, ask someone you trust to take over. Never sleep in the same bed as your baby if you have taken any substance that causes sedation — including alcohol, benzodiazepines, opioids, or cannabis. The safest sleep for your baby is always in their own cot, on their back, with no soft bedding. In Belgium, free addiction support is available through your GP, and through Télé-Accueil (0800 32 123, 24h/day, anonymous). Outside Belgium, call your local emergency number or crisis line.
If anything changes
Call us immediately if your baby is unusually sleepy, hard to wake, breathing slowly, or having seizures — call 112 at once. And if you ever feel too unwell to care for your baby safely, please ask someone you trust to step in.
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 24 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: 24 September 2026