Drugs Medicines and Pregnancy

Harmful Drugs during Pregnancy
Be careful of harmful drugs and medicines during pregnancy

Drugs Medicines and Pregnancy is a taboo topic, during pregnancy a lot of prescription drugs medicines and pregnancy can be harmful when combined with being pregnant and the growing foetus during pregnancy needs special care. During pregnancy a lot of prescription drugs and medicines can be harmful to the growing foetus during pregnancy. During pregnancy some drugs and medicines can affect the foetus developing by passing through the placenta. Pregnancy itself can also interfere with some medications, hindering their performance, therefore it is usually better not to take any drugs at least three months before conceiving and the first trimester.

Whilst being pregnant or breastfeeding you should always seek advice from your GP before taking any medicines or drugs.

However there are some medical conditions that require medication even during pregnancy such as:-

  • Diabetes
  • Epilepsy
  • Schizophrenia
  • Some cases of depression

Prescription Drugs and Medicines

A lot of drugs and medicines are only available through prescription now, but this does not necessarily mean that they are safe to use during pregnancy. Always consult with your own doctor if you are unsure.

Some of these particular drugs and medicines are:-

Anti Cancer Drugs
Anti Cancer Drugs
    • Anti Cancer Drugs
    • Aspirin
    • Carbimazole
    • Chloroquin
    • Ibuprofen
    • Lithium
    • Metformin
    • Oral medicines for cystitis
    • Phenytoin
    • Radiation from x-rays
    • Skin preparations containing vitamin A
    • Some antibiotic
    • Tetracyclines
    • Thyroxine
    • Vaccines for measles, rubella and yellow fever
    • Warfarin and other anti-coagulants

Should you be in any doubt then do not hesitate to seek advice from a registered health professional.

Medicines and Prescription Drugs



Paracetamol during pregnancy is usually considered to be safe in small doses only. If you are at risk of pre-eclampsia then it is safe to use aspirin, but again only in a low dosage. Indomethacin and some other non-steroidal anti-inflammatory drugs are known to cause damage to your babys kidneys and cause them to bleed so these should be avoided at all costs.

Anti-Acne Tablets

Anti Acne Drugs
Anti Acne Drugs

Any that contain vitamin A compounds (retinoic acid) should be avoided as they are known to cause birth defects. Tetracycline and minocycline (antibiotics to treat acne) should also be avoided as they will soften babys bones and discolour teeth.


Avoid all antibiotics as they interfere with the metabolism in the gut and there are many types that are useless against viral infections and weaken the bodies natural immune system with prolonged usage. Some are considered unsafe to take during pregnancy due to causing birth defects.


(blood thinning agents)

Heparin is safe to use during pregnancy as it cannot pass through the placenta to the foetus, however constant use (more than 6 months) can damage your bones and lead to osteoporosis. Warfarin can cause bleeding in your foetus and therefore should not be taken in the first and last trimesters.


Anti Convulsants
Anti Convulsants

Anti-convulsants when taken by pregnant women are at high risk of producing a malformed baby. The bodies need for Vitamin D is intensified and the risk can be avoided by taking magnesium and manganese which research has shown that the convulsions will stop in most cases.


Anti Depressants
Anti Depressants

Anti Depressants are known to cause decreased sperm counts and mobility. They can be avoided by taking magnesium, manganese and B complex vitamins.


(Blood Pressure Tablets)
Anti Hypertensives
Anti Hypertensives

Methyldopa and labetatol are considered to be fairly safe as they have been studied for years. Nifedipine on the other hand is quite new and adverse ramifications are probable due to a lack of understanding of it. Pregnant women should stay clear of any Beta-blockers and angiotensin converting enzyme inhibitors, they are very dangerous during pregnancy. You should consult with your local GP if you become pregnant whilst you are taking hyper tensive tablets.

Anti-Migraine Tablets

Anti Migraine Tablets
Anti Migraine

Almost all of these tablets are ergotamine-based substances. These are dangerous during pregnancy because they can cause miscarriages and cause the womb to contract. Do not take anti migraine tablets without consulting your GP if you are pregnant.

Anti-Thyroid Tablets

These are potentially dangerous for the Foetus as Anti-Thyroid drugs including carbimazole and propyithiouracil have been known to pass through the placenta and cause problems with your babies thyroid.


Aspirin Tablets

Aspirin has been known to pass through the placenta and cause a brain and liver disorder that affects children. This condition is called Reyes Syndrome, which is becoming increasingly more common.


(Water Removal Tablets)

Diuretics (Water removal tablets) should be avoided at all costs.

Only take if they are prescribed by a doctor.

Epilepsy Tablets

This medication does possess a minor risk to your unborn foetus, but should you not continue with the medication then the risk that now applies to both you and your childs health is severely greater. Always discuss pregnancy with your doctor as most Epileptics require supplements to top up low levels of Folic Acid.



The Foetus may suffer abnormal development and labour.

It also has been known to have been delayed when these drugs have been taken in the third trimester of pregnancy.



This is considered safe for your baby because it cannot pass through placenta.

Diabetics must keep a good level of blood sugar level as the glucose on the other hand can pass through the placenta and affect your baby.


Lithium is to be avoided during pregnancy because it is known to affect the thyroid and cause drowsiness of your baby.

Oral Medicines For Cystitis

Oral Cystitis
Oral Cystitis

Oral Cystitis medications are proved to be unsafe for both women who are pregnant and lactating, therefore they are best to be avoided.

Tranquilizers And Sleeping Pills


Diazepam and Temazepam ( benzodiazepines ) should be avoided at all costs during pregnancy as they are connected with all kinds of problems in children that stem from their time in the womb.

They are known to cause malformations that are clearly visible, motor development impediments, behavioural problems.

In the early stages of pregnancy they are known to cause problems with the development of the central nervous system.

Tranquilisers are taken as they can counteract over-stimulation from substances like coffee, but over-stimulation can be caused by deficiencies in Zinc, Magnesium, Manganese and Vitamin B Complex.

Recognition of these are easier to treat if you consult with your doctor before taking anything.