Medications and Pregnancy: What You Should Know

Today, we'll talk to you about medications and pregnancy, as some medications can be dangerous and put the child's health at risk.
Medications and Pregnancy: What You Should Know

Last update: 12 October, 2021

Some discomforts are common during pregnancy and often lead us to think about taking medications to alleviate them. But are they safe for this stage?

This question is very frequent and must be brought to your doctor, as some drugs or substances that are consumed in pregnancy reach the baby through the placenta.

Below, we’re going to tell you everything you need to know about medications during pregnancy so that you understand why you need to take precautions in this regard.

How do you know if a drug is safe during pregnancy?

During pregnancy, women must take care regarding their own health and that of the developing fetus. With this in mind, it’s important to avoid the consumption of certain foods and substances that are potentially harmful to her or the baby.

Medicines are chemicals made for the purpose of treating illnesses or alleviating certain discomforts. However, they can have adverse effects on the fetus, ranging from malformations to intrauterine death. These negative effects on fetal development are called teratogenic.

On the other hand, there are drugs that don’t cross the placenta but that, at the same time, increase the risk to the baby’s health. For example, through some of the following effects on the pregnant woman:

  • Increased uterine tone, which favors the appearance of contractions.
  • Alteration of blood flow in the placenta, which interferes with the exchange of gases and nutrients between mother and baby.
  • Damage to different organs of the mother, a situation that can condition the lives of both.

Above all, pregnant women should use drugs to improve their health and should avoid them when the risk outweighs the benefit. For this reason, it’s important not to consume any drug without the corresponding medical prescription.

A doctor giving a prescription to a patient.

The classification system of safe drugs in pregnancy

In 1970, the United States Food and Drug Administration (FDA) created a drug classification system, which establishes the risk of fetal involvement for each drug. The objective of this is to provide professionals with the necessary guidance for the appropriate pharmacological prescription of pregnant women.

This system classifies drugs into 5 categories of teratogenic risk (A, B, C, D, or X), according to the information available from scientific studies.

In this sense, category A is the safest for pregnancy and X, the most dangerous. Most drugs fall into group C, which implies that there’s not enough information to guarantee their complete safety.

Although doctors usually discuss this topic during prenatal visits, many people are unaware of the risk or underestimate it.

According to data from the Centers for Disease Control and Prevention (CDC), 90% of women take medications at some point during their pregnancy and in only 70% of cases, a professional has prescribed them.

What should you keep in mind about medications during pregnancy?

Certainly, medications are necessary to treat many health disorders and pregnant women aren’t exempt from suffering from them. Some pregnant women have previous chronic diseases, while others acquire them during pregnancy.

In both cases, we recommend some preventive measures.

Tell your doctor if you suffer from any disease

If you’re taking medications to treat chronic diseases, you should discuss this with your doctor from the preconception consultation. This way, the professional can assess the risks and better advise you.

In the event that there’s no specific need, it’s best to avoid exposing your baby to medications and other chemicals.

Look for reliable information

Currently, we have a lot of information about diseases and medicines available on the internet. However, it’s not always a reliable source or isn’t interpreted correctly.

Therefore, it’s best to pay attention to the recommendations of your obstetrician or your nurse, who are surely sufficiently up to date on the subject.

Limit the use of medications

The more drugs you take during pregnancy, the greater the chance of harm to the fetus. For this reason, you need to balance the risks and benefits and avoid the consumption of all drugs that aren’t essential.

Avoid over-the-counter medications

Over-the-counter drugs are just as risky as prescription drugs, and in fact, many of them combine different chemicals. For example, we can mention the medications for the flu or other common conditions.

Don’t consume plants or natural remedies without medical approval

Although they claim to be safe for pregnancy because they’re, this isn’t always true. Many plants and natural remedies can stimulate uterine activity and cause harm to your health and that of your baby.

In addition, scientific information on the use of these compounds in pregnant women is very scarce, which makes it difficult to ensure the safety of consumption at this stage. If you want to try these alternatives, it’s important that you get an okay from your obstetrician first.

Medications used in pregnancy

The discomforts in pregnancy are common and varied: Abdominal discomfort and headaches, nausea, heartburn, constipation, hemorrhoids, among others. For this reason, the most commonly used medications during pregnancy are the following:

  • Acetaminophen: Approved as an analgesic (for pain) or fever reducer for pregnancy.
  • Antacids: These are used for upset stomach, and only those that contain calcium carbonate or proton pump inhibitors are allowed.
  • Antihistamines (antiallergics): Among them, loratadine is a good option, but you should avoid this type of medication during the first trimester.
  • Fiber laxatives: Options such as ispaghula can be used, but it’s best to improve your eating patterns.
  • Antibiotics: Their indications depend on the causative agent and the mother’s health context.
  • Prenatal vitamins: These are recommended to prevent birth defects and to make up for any nutritional deficiencies.

Medications that you shouldn’t consume in pregnancy

Next, we’ll mention some medications that are contraindicated throughout pregnancy:

  • Dicoumarin anticoagulants
  • Angiotensin-converting-enzyme inhibitors (ACE) inhibitors (captopril, enalapril)
  • Diethylstilbestrol
  • Fluconazole in high doses
  • Methimazole
  • Synthetic retinoids
A doctor talking to a pregnant woman about her medical history.

Don’t self-medicate!

If you have any need for treatment during pregnancy, discuss this with your doctor first. This way, you can receive the appropriate advice to resolve the discomfort without taking unnecessary risks to your health and that of your baby.

Remember that your baby receives everything you eat, and although it seems to you that what you take is totally safe, it’s not always so.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.



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