Medications During Pregnancy: Risks and Consequences

It's important to make pregnant women aware of the risk of consuming medications during pregnancy without proper medical supervision.
Medications During Pregnancy: Risks and Consequences

Last update: 26 February, 2022

In this post, we want to provide the best information to avoid risky situations for both the fetus and the mother. We also want to emphasize the importance of making the female population aware of the risk of certain medications during pregnancy and the consumption of drugs in order to avoid irreversible damage to their future baby.

During pregnancy, it’s important to avoid taking drugs, including nutritional supplements and medicinal plants, as everything a mother ingests reaches the bloodstream and passes to the fetus, just as nutrients for fetal development.

This recommendation is due to the fact that various health organizations, including the World Health Organization (WHO) estimate that more than 90% of pregnant women consume drugs or over-the-counter products, which are responsible for 3% of congenital anomalies.

Risks of taking medications during pregnancy

A black and white photo of a pile of pills and capsules.

The consumption of medications during pregnancy without medical prescription can harm the health of the fetus and even in extreme cases cause the death of the fetus. This issue is usually extremely delicate and one must be absolutely responsible when taking them for the following reasons:

  • Drugs act directly on the fetus, affecting its development and may cause malformations and deformities, which is called the teratogenic effect.
  • It attacks the placental blood vessels and reduces the exchange of oxygen and nutrients between the fetus and the mother.
  • It contracts the uterine muscles and decreases the amount of blood that the fetus should receive, causing congenital anomalies.

However, in each trimester of pregnancy, the risk of affectation is different and will depend on the age of the fetus, nature, potency, and dosage of the drug consumed.

First Trimester

During this time, the development of the organs takes place, leaving the fetus highly vulnerable to everything it receives from the mother’s placenta and the risk of health problems is high. At the end of this period, it’s likely that the consumption of drugs won’t cause obvious congenital anomalies, but it does alter the growth and function of tissues.

Second Trimester

During this stage, drug use can seriously affect the baby’s growth and nervous system development.

Third Trimester

In this last stage, drug use increases the risk to the fetus of presenting respiratory distress and complications after delivery.

The Golden Rule: Consume only the medications prescribed by your treating physician in the amounts and doses indicated in order to reduce the probability of affecting the fetus.

Medications that shouldn’t be consumed

Pillls and capsules.

It’s important to take into account that certain medications can cause serious birth defects in the fetus, for this reason. the consumption of the following should be avoided:

  • Aspirin and other non-steroid analgesics
  • Anxiolytics and antidepressants
  • Opioid analgesics, barbiturates
  • Gastric mucosal protectants
  • Antispasmodics/anticonvulsants
  • Lithium
  • Diuretics and anabolic agents
  • Antibiotics such as tetracyclines or aminoglycosides
  • Retinoic acid
  • Radioactive iodine and methimazole (for thyroid problems)
  • Certain drugs for acne and other skin problems (such as isotretinoin and etretinate)
  • Cancer chemotherapy (cytostatic drugs)
  • Sex hormones, such as synthetic progestins, androgenic (masculinizing) hormones, and diethylstilbestrol (DES), a synthetic estrogen
  • Amphetamines
  • Anticoagulants, some antiarrhythmic, and antihypertensive drugs
  • Certain medications for hair loss

Vaccines during pregnancy

While it’s true that vaccines protect the body from viral diseases, it’s also true that during pregnancy isn’t the best time to get them, as most of them contain live viruses that can cause infections to the placenta and the fetus.

The decision to use them will depend on the imminent risk situation to which each expectant mother is exposed. The patient should of course be evaluated beforehand by the attending physician.

General Recommendations

As pregnancy is a relatively long period, in which women are exposed to constant hormonal changes and in which the administration of a drug may be necessary to solve a medical condition having to do with gestation or a chronic ailment, experts recommend the following.

  • Maintain good communication with the treating physician.
  • Evaluate together with your doctor the “Risk/Benefit” ratio before making the decision to treat the disease with the corresponding drugs, taking into account the therapeutic dose and the time of application.
  • Avoid those drugs with multiple active ingredients in their composition.
  • Avoid, as much as possible, those drugs recently marketed.

It’s important to remember that prevention can help you enjoy a happy pregnancy and have a healthy baby.


This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.