Are antibiotics safe in pregnancy? The most prescribed medications during pregnancy are antibiotics.

They are routinely prescribed for health issues including urinary tract infections, bacterial infections, and group B strep. Of course, as a pregnant woman, it's important to know whether or not medications are safe to take.

Fortunately, there is a lot of information about antibiotic use during pregnancy. Some antibiotics are safe during pregnancy, while others are not. It's always important to get all the details on the medication. Weigh the risks and benefits, ask good questions, and decide if you need the medication. Keep in mind, there are many variables that might play into your particular decision. So, take time to consider the reason for medication, the duration you must take it for, and the gestational age of your baby.

General Overview: Is Medication Safe During Pregnancy?

According to the FDA, most women take at least one medication during pregnancy. Whether you have a chronic condition that requires medication, or you have an acute health issue during pregnancy, research the medication and discuss your options with your doctor.

While some medications are proven harmless to your growing baby, other medications can cause issues. What can make things a little tricky is that many medications haven’t been explicitly studied on pregnant women. No one will put pregnant women at risk in order to conduct a study.

That said, many common medications, including mental-health drugs and antibiotics, have been researched for safe use during pregnancy.

Medication Classification During Pregnancy

Beginning in 1979, the FDA required all medication to be labeled using a letter-category system. The system ranks and discloses any known risks a medication may present for both pregnant and lactating women.

These classes include A, B, C, D, and X. This information below has been sourced and paraphrased from this guide.

• Category A: Well-controlled studies done on pregnant women have failed to show risks to babies during any trimester. Examples include thyroid medications and folic acid.
• Category B: Studies on pregnant animals have failed to prove a risk to growing babies, but there are no well-controlled studies on pregnant women. Many antibiotics fall into this category.
• Category C: Animal studies have shown possible adverse effects. There are no adequate studies in humans, but the potential benefits may outweigh the risks. Examples include some pain medications (like gabapentin) and anti-depressants.
• Category D: There is evidence of harm to your unborn baby based on “adverse reaction data from investigational or marketing experience or studies in humans.” Potential benefits may warrant the use of the drug for some pregnant women. One example is a blood pressure medication.
• Category X: Studies in animals or humans show a definite risk, and risks clearly outweigh potential benefits.

While this system provides helpful information, it’s widely criticized for being too simplistic. In 2015, a new system was put into motion. The new system aims to provide more information including how much medicine may get into breastmilk, implications on fertility, and risks to the unborn baby. The new system creates an updated database to help providers and women make more informed decisions.

You can learn more by viewing the entire draft guidance put out by the FDA here.

Are Antibiotics Safe During Pregnancy?

Some antibiotics are most likely safe. According to the American Family Physician, penicillin G and penicillin V potassium carry no known developmental risk factors. They also explain that there are not any adverse effects related to amoxicillin, doxycycline, Levaquin, chloramphenicol, and rifampin.

In a research study based on information from 35,000 women diagnosed with UTIs during pregnancy, the most commonly prescribed antibiotics were:

• Nitrofurantoin
• Cephalosporin
• Penicillin

Unsafe Antibiotics During Pregnancy

A 2009 study from the Reviews in Obstetrics & Gynecology Journal states that the following antibiotics should be avoided during pregnancy:

• Streptomycin and Kanamycin (may cause hearing loss).
• Tetracycline (can cause weakening, hypoplasia, discoloration of bones and teeth).
• Bactrim and Macrobid (linked to brain malformations and heart defects).

Why Might Pregnant Women Need Antibiotics During Pregnancy?

There are two common reasons for antibiotics during pregnancy: UTIs and Group B Strep. Outside of these two scenarios, pregnant women may need antibiotics for other reasons not specific to pregnancy.

Urinary Tract Infections

UTIs are more common during pregnancy because of the pressure your baby puts on your bladder and urinary tract. This pressure can trap bacteria. Additionally, urine has more sugar and hormones that encourage bacterial growth and infection to form. It’s important to treat UTIs during pregnancy to prevent the development of a kidney infection or even sepsis.

Group B Strep

GBS is a naturally occurring bacteria present in 10-30% of all women.

Most women have no idea they have it because it causes no harm to them! However, it matters during pregnancy because you can pass GBS on to your newborn during delivery.

For your baby, GBS poses some serious risks including meningitis, pneumonia, bacteremia, and sepsis. All of these risks are potentially fatal. Antibiotics are recommended for treatment because they decrease your baby’s risk of contracting GBS disease from 1 in 200 to 1 in 4000.

Guidelines: How to Safely Take Medication During Pregnancy

There are general guidelines you should follow before you take medication.

• Only used medication when absolutely necessary.
• Avoid medication during the first trimester whenever possible.
• Select a safe medication with a proven track record.
• Use of a “single-agent therapy” is preferred whenever possible.
• Use the lowest effective dose.
• Avoid the use of OTC medications when taking prescription medications if possible.

These guidelines are helpful for all pregnant women. The most important takeaway here is to avoid medication during the first trimester — if possible.

This is when antibiotics specifically pose the most risk to your unborn baby.

Limit Antibiotics During Pregnancy

Overall, you want to limit the use of antibiotics during pregnancy within reason. There are a few reasons why including risks of side effects to both mother and baby.

Risks to Mother

Antibiotics carry the risk of a wide range of uncomfortable symptoms for a mother including:

• Digestive upset
• Vomiting
• Yeast or other fungal infections
• Diarrhea
• Bloating
• Decreased appetite
• Stomach cramping

Risk to Baby's Microbiome

When antibiotics are administered during birth (due to GBA), research shows that a baby’s microbiome is negatively impacted. In some cases, research shows a less diverse microbiome or reduced amounts of beneficial gut bacteria for up to 3-12 months after birth.

This isn’t to say you should decline antibiotics when you are GBS positive. However, I recommend understanding the risk to your baby so that you can support your baby's gut health.

One of the most effective lines of defense is reseeding your microbiome with fermented foods and the use of a targeted, high-quality probiotic before and after birth. Having healthy bacteria in your gut helps your body absorb and distribute nutrients throughout your body, ultimately helping your baby's immune system in-utero.

My Experience with Antibiotics During Pregnancy

I personally had to have antibiotics during pregnancy and labor. I was GBS positive and ultimately decided the benefits of antibiotics during labor outweighed the side effects.

Serious side effects of contracting GBS as a baby include having pneumonia, sepsis, or meningitis. While I do and don't regret my decision, the course of antibiotics definitely wiped out my son’s gut bacteria and microbiome. I wish I had realized how serious this was! At the very least, I wish I would have known to bring a probiotic supplement to the hospital with me.

With this in mind AND for the safety of your baby, I think it’s important to only take an antibiotic when deemed absolutely necessary during pregnancy (and any time for that matter!). I can’t give you specific advice for your situation, but I will urge you to discuss the decision with your provider.

Make an Informed Choice, Mama

It's not an easy decision. But remember that the most important part of your decision should be a detailed discussion with your provider. If you do need an antibiotic, be sure to support your body by pairing it with a high-quality probiotic. And know that whatever your ultimate decision is, you are already doing what’s best for you and your baby.

FAQs

More questions about antibiotics during pregnancy? Read on!

Can antibiotics cause birth defects?

It's not advised to take certain classes of antibiotics during pregnancy due to the risk of birth defects. According to a UK study, mothers given antibiotics in the macrolide class were 55% more likely to have a baby with major birth defects. However, commonly prescribed antibiotics during pregnancy (like penicillin) have not been associated with an increased risk for birth defects.

Not surprisingly, the risk of birth defects when using antibiotics was also linked to first-trimester first-trimester usage.

Do antibiotics affect early pregnancy?

It depends on the antibiotics. Antibiotics that are safe during pregnancy, are generally safe to use during the first trimester as well. The antibiotics that are unsafe during pregnancy are more dangerous during the first trimester. This becomes particularly important if you take an antibiotic considered unsafe for pregnancy before knowing if you're pregnant. So, always tell your doctor if you suspect pregnancy before taking an antibiotic. That way, your doctor can stick to pregnancy-safe medications just in case.

Can an infection cause harm to my unborn baby?

Yes. Of course, it depends on the infection. Common colds or topical skin infections like acne do not cause any harm to an unborn baby. However, certain infections can pass to the fetus and lead to birth complications or other serious illnesses for a baby. Infections like GBS, bacterial vaginosis, UTIs, yeast infections, toxoplasmosis, CMV, HSV, and Zika can be very dangerous without proper treatment.

How can I avoid infection during pregnancy?

It's easy to become anxious about infections during pregnancy, but there are easy steps to take to reduce your risk of acquiring an infection during pregnancy.

Always follow food hygiene safety, don't eat undercooked meat, don't share foods and drinks with other people (including your own children), don't change the kitty litter, and wash your hands often.

Are infections common during pregnancy?

Yes, infections are common during pregnancy.

Between a lowered immune system, increasing hormones, and pregnancy-related susceptibilities, a pregnant woman is more prone to infection. Always talk to your doctor if you're feeling unwell or think you might have an infection. Your provider can weigh the risks of using antibiotics against the risk of infection.

It's generally better to get treatment than let an infection get worse. However, some infections do not require treatment.

Did you take antibiotics during pregnancy? How did you make your decision? I'd love to know!