Most medication labels say 'consult your doctor if pregnant' — but that's not the same as unsafe. Five questions for making genuinely informed decisions about any medication during pregnancy.
Medication in pregnancy sits between two unhelpful extremes — taking everything without thinking and avoiding everything out of fear. Both carry real risk. This guide offers a five-question framework for making informed decisions about any medication during pregnancy.
The quick answers first: Paracetamol is safe in pregnancy at the recommended dose for short-term use. Ibuprofen should be avoided from 30 weeks and used cautiously before that — use paracetamol instead. Aspirin at low dose (75mg) is actually prescribed in pregnancy for certain risk factors. At standard doses, avoid. Always tell any prescriber you are pregnant.
This is the question that gets missed most often. Untreated conditions in pregnancy frequently pose greater risks to the baby than the medication used to treat them. Examples:
Untreated depression and anxiety in pregnancy are associated with adverse outcomes — preterm birth, low birth weight, attachment difficulties. The evidence for continuing appropriate antidepressants in pregnancy is often stronger than stopping them.
Asthma uncontrolled during pregnancy poses oxygen risk to the baby. Inhalers are safe.
Epilepsy with poorly controlled seizures is a significant risk. Anti-epileptic medication continues under specialist oversight.
Untreated UTI can trigger preterm labour.
The question is never just 'is this medicine safe' but 'what happens if this condition isn't treated?' Both sides of the risk equation matter.
The leaflets in almost all medications say 'not recommended in pregnancy' or 'consult your doctor before use if pregnant.' This is not the same as 'unsafe in pregnancy.' Most medications carry this label as a legal precaution because large randomised trials of medications in pregnant women are not routinely conducted for ethical reasons.
'No evidence of harm' and 'no evidence it is safe' are different statements. For many commonly used medications, evidence of safety in pregnancy comes from decades of widespread use, observational studies, and animal data. The UK Drugs in Lactation Advisory Service (UKDILAS) and the Bumps website (bestuse ofmedicinesinpregnancy.org.uk) are the best sources of balanced, evidence-based information on specific drugs.
For medications where there is some uncertainty, both dose and duration matter. Taking a short course of something well-evidenced is a different risk profile from taking a high dose continuously throughout pregnancy.
If you need antihistamines for a week, that is different from taking them daily for six months. If you need pain relief for three days, paracetamol at standard dose is different from regularly combining multiple analgesics.
This question also applies in the other direction: if you've been avoiding a medication you were prescribed before pregnancy, is there a lower dose that would be safer to continue than stopping abruptly? Stopping some medications suddenly — particularly antidepressants and blood pressure medications — can carry its own risks.
The trimester matters. Different stages of pregnancy have different vulnerability profiles:
First trimester (weeks 1–12): the period of organogenesis — when organs are forming. The highest-risk period for teratogenic effects (where medication can disrupt organ development). Greatest caution applies here.
Second trimester (weeks 13–26): generally the lower-risk period for most medications.
Third trimester (weeks 27–40): certain medications carry new risks related to effects on the baby near delivery — including NSAIDs (ibuprofen) which can affect fetal kidney function and the ductus arteriosus from 28 weeks, and some medications that can affect neonatal adaptation.
When a specific medication is flagged for a particular trimester, this is the reason. It doesn't mean it's dangerous in all trimesters — it means the risk profile is trimester-specific.
This sounds obvious but it's frequently overlooked — particularly for medications people buy over the counter, or for conditions managed by specialists who may not know about the pregnancy, or in the early weeks before the pregnancy is disclosed widely.
Your pharmacist is an underused resource. Pharmacists are trained in medication safety in pregnancy and are available without an appointment. If you're buying an OTC medication and you're pregnant, tell the pharmacist — they will give you the relevant advice in minutes.
For prescription medications: you are entitled to ask your prescriber specifically about safety in pregnancy and to ask for the evidence rather than just the recommendation. If you're not satisfied with the answer, a GP with a special interest in obstetrics or a specialist pharmacist (through your maternity unit) can give more detailed guidance.