10 Tablets That Are Less Safe in Pregnancy

10 Tablets That Are Less Safe in Pregnancy

We will now describe 10 tablets that are less safe in pregnancy.

1. Isotretinoin (Roaccutane)

Commonly used for severe acne, this is one of the most high-risk medications available. It carries a significant risk of severe brain and heart defects. Most countries require a strict “Pregnancy Prevention Programme” for anyone prescribed this drug.

2. Sodium Valproate (Epilim)

Used for epilepsy and bipolar disorder, this medication is linked to physical birth defects and long-term developmental or learning delays. It is typically only used if no other treatment is effective.

3. ACE Inhibitors (e.g. Ramipril, Enalapril)

These blood pressure medications (often ending in -pril) can cause foetal kidney failure and skull defects. If you are treating hypertension, your GP will likely switch you to a safer alternative like Labetalol or Methyldopa.

4. ARBs (e.g. Losartan, Candesartan)

Similar to ACE inhibitors, these “sartan” drugs pose a high risk to the baby’s renal (kidney) development and should be avoided, especially in the second and third trimesters.

5. NSAIDs (e.g. Ibuprofen, Naproxen, Diclofenac)

Non-steroidal anti-inflammatory drugs should be avoided, particularly after week 30. They can cause a vital blood vessel in the baby’s heart to close prematurely, leading to high blood pressure in the baby’s lungs.

6. SGLT2 Inhibitors (e.g. Dapagliflozin)

Used for Type 2 diabetes, heart failure and CKD, these newer medications (the “gliflozins”) are avoided because they may interfere with the baby’s kidney development during crucial growth phases. They should be stopped when a woman is planning a pregnancy.

7. Lithium

Commonly prescribed for bipolar disorder, Lithium is associated with Ebstein’s anomaly (a heart valve defect) when taken during the first trimester. It requires extremely close specialist monitoring if no other options exist.

8. Oral Decongestants (e.g. Pseudoephedrine)

Found in many “behind-the-counter” cold and flu tablets, these work by narrowing blood vessels. This can inadvertently restrict blood flow to the placenta and the baby.

9. High-Dose Vitamin A (Retinol)

While Vitamin A is necessary, high doses (found in liver products or non-pregnancy-specific supplements) are teratogenic. Avoid supplements containing Retinol and stick to prenatal-specific vitamins.

10. Tetracycline Antibiotics

Specific antibiotics like Doxycycline or Tetracycline are generally avoided after the first trimester as they can cause permanent discoloration of the baby’s developing teeth and affect bone growth.

5 Other Medications to Avoid

Here are 5 additional medications that are generally avoided or heavily restricted during pregnancy:

• Warfarin: This blood-thinner can cause “foetal warfarin syndrome,” which leads to facial abnormalities and central nervous system defects, so doctors typically switch patients to heparin.

• Methotrexate: Used for rheumatoid arthritis or psoriasis, this drug interferes with folic acid metabolism and can cause severe malformations or pregnancy loss.

• Thalidomide: Now used for specific cancers and skin conditions, it remains one of the most dangerous teratogens known, causing severe limb underdevelopment.

• Amiodarone: This heart rhythm medication contains high levels of iodine, which can lead to significant thyroid dysfunction and goiters in the developing baby.

• Phenobarbital: An older anti-seizure medication that, when used in pregnancy, is associated with an increased risk of heart defects and oral clefts (like cleft palate).

Top Tip: If you are unsure about an over-the-counter herbal supplement, look for the THR (Traditional Herbal Registration) mark, but always verify it with a pharmacist first.

Quick Reference Summary

Note: Never stop taking a prescription medication (especially for epilepsy or mental health) without consulting your doctor first, as the risk of untreated illness can sometimes outweigh the medication risk.