Medicines in pregnancy: what is usually safe, what is not, and how to check

The principle

Every medicine in pregnancy is a balance between the risk of the drug and the risk of leaving the condition untreated. A high fever, an untreated urinary infection, uncontrolled asthma, epilepsy or thyroid disease all carry real risks to a pregnancy — often greater than the medicine's.

So the rule is not 'take nothing'. It is: nothing without telling a doctor or pharmacist that you are pregnant, and no medicine stopped on your own because you have just found out you are pregnant.

That applies to ayurvedic, homeopathic and herbal preparations as well. 'Natural' is not a safety category, several herbal products are unsuitable in pregnancy, and Indian herbal products have repeatedly been found to contain undeclared ingredients and heavy metals.

Commonly used and generally considered safe

Paracetamol for fever and pain, at the standard dose and not continuously for long periods — it is the first-line painkiller in pregnancy.

Most antacids, and specific acid-reducing medicines your doctor names, for the heartburn that almost every pregnancy brings.

Several antibiotics, including the penicillin group and certain others, are used routinely in pregnancy for infections — which is exactly why a urinary infection should be treated rather than endured.

Iron, folic acid, calcium and vitamin D as prescribed; anti-nausea medication such as doxylamine with vitamin B6 for morning sickness; and the medicines for asthma, thyroid disease and diabetes, which are continued and adjusted rather than stopped.

Vaccines: tetanus-containing (Td), influenza and others as advised are given deliberately in pregnancy, because the antibodies protect the baby too.

To avoid, and to check

Avoid unless a doctor specifically prescribes: ibuprofen and other anti-inflammatory painkillers, particularly in the third trimester; most antibiotics of the tetracycline and quinolone groups; high-dose vitamin A and its derivatives, including oral acne medicines, which cause serious birth defects; and most over-the-counter cold and cough combination syrups, which contain several ingredients you did not intend to take.

Check before continuing: blood pressure medicines (some classes are changed in pregnancy), epilepsy medicines (which must be reviewed rather than stopped), acne treatments, mental-health medicines (many are continued because untreated illness is more dangerous), and anything for migraine.

Never take: someone else's prescription, a leftover strip from a previous illness, or a medicine bought over the counter on a chemist's recommendation without saying you are pregnant. India's over-the-counter availability is exactly where this goes wrong.

And two absolutes: no alcohol and no tobacco in any form, including chewed tobacco.

When to see a doctor

Same-day: fever above 38°C, burning urination or back pain (urinary infections in pregnancy can trigger preterm labour and need treating), vomiting that will not stop, severe headache with visual changes, breathlessness, or any medicine reaction such as a rash or swelling.

Before conception or as soon as you know you are pregnant: bring every medicine you take — prescription, over-the-counter, herbal and supplements — to your doctor in a bag and go through them. That single appointment prevents most medicine problems in pregnancy.

This article is general information, not medical advice, and is no substitute for personal medical advice. For any decision about your or your child's health, please consult your doctor.

Frequently asked questions

Q: I took a painkiller before I knew I was pregnant. — Very common, and usually nothing to worry about, particularly with paracetamol. Tell your doctor exactly what and when, and let them advise rather than worrying alone.

Q: Can I take my regular thyroid medicine? — Yes, and requirements usually rise in pregnancy, so it needs testing and dose adjustment early. Stopping it is the dangerous option.

Q: What can I take for a cold? — Rest, fluids, steam, saline drops and paracetamol for fever. Skip the combination syrups, and see a doctor for fever above 38°C, breathlessness or a cough lasting more than a week.

Q: Are ayurvedic medicines safer in pregnancy? — Not automatically. They are less regulated, doses are unstandardised, and some ingredients are unsuitable in pregnancy. Tell your obstetrician about anything you are taking, from any system of medicine.