Antibiotics And Pregnancy: What's Safe?

Taking antibiotics during pregnancy is a common occurrence, with around 30% of pregnant people requiring at least one course of antibiotic treatment. While some antibiotics are considered safe for use during pregnancy, others may cause harm to the baby, such as growth problems or other health issues.

Pregnant women are typically advised to be cautious with medications, remedies, and over-the-counter drugs as some medicines can pass through the placenta and affect the baby's growth. Antibiotics are no exception, and while they are important for treating bacterial infections, not all antibiotics are created equal when it comes to pregnancy.

So, which antibiotics are generally considered safe during pregnancy, and which ones should be avoided?

Safe antibiotics during pregnancy

It is common for pregnant women to need antibiotics, with around 30% of over 13,000 pregnant people in one study having had at least one course of antibiotic treatment between the three months prior to conception and the end of their pregnancies.

Some antibiotics are considered safe during pregnancy, including:

• Penicillins, including amoxicillin and ampicillin
• Macrolides, including erythromycin and azithromycin
• Cephalosporins, including cephalexin
• Metronidazole, which is used to treat some vaginal infections, such as trichomoniasis and bacterial vaginosis, as well as other kinds of infections

However, it is important to consult a doctor before taking any antibiotics during pregnancy, as some can be harmful to the baby. Antibiotics that should be avoided during pregnancy include:

• Tetracyclines, such as tetracycline, which can cause permanent yellow or grey discolouration to bones and teeth
• Fluoroquinolones, such as ciprofloxacin, levofloxacin, and moxifloxacin, which have been linked to an increased risk of birth defects
• Streptomycin, which may cause hearing loss in the baby

Antibiotics to use with caution

While many antibiotics are considered safe during pregnancy, there are some that should be used with caution. These include antibiotics used to treat urinary tract infections (UTIs), which are common during pregnancy and can cause complications if untreated.

Nitrofurantoin (Macrobid)

Nitrofurantoin has been associated with some birth defects. The American College of Obstetricians and Gynecologists recommends avoiding this antibiotic during the first trimester, when most foetal development occurs, to prevent possible birth defects.

Trimethoprim and sulfamethoxazole (Bactrim)

Trimethoprim is often combined with another antibiotic, sulfamethoxazole, to treat UTIs. Both drugs have been linked to an increased risk of birth defects, and the American College of Obstetricians and Gynecologists suggests avoiding them during the first trimester of pregnancy.

Trimethoprim may not be suitable during pregnancy as it blocks the effects of folic acid, which is crucial for reducing the risk of neural tube defects and other birth defects. However, taking a daily folic acid supplement of at least 400 micrograms may counteract this effect.

Fluoroquinolones

Fluoroquinolone antibiotics, such as ciprofloxacin (Cipro), levofloxacin (Levaquin), and moxifloxacin (Avelox), are not typically used during pregnancy due to the risk of causing birth defects. They may harm a baby's developing heart, kidneys, or brain.

Metronidazole (Flagyl)

Metronidazole is an antibiotic used to treat certain infections, such as bacterial vaginosis. While it may be safe during the second and third trimesters, its use in the first trimester is linked to premature birth and an increased risk of miscarriage. However, more studies are needed to confirm these links.

Sulfamethoxazole/trimethoprim (Bactrim)

There is conflicting data on the safety of sulfamethoxazole/trimethoprim during the first trimester. Taking this antibiotic early in pregnancy is associated with an increased risk of cleft palate, heart defects, and neural tube defects. It is also linked to an increased risk of kernicterus, a severe form of infant jaundice that can cause brain damage, when taken towards the end of pregnancy.

Antibiotics to avoid during pregnancy

Antibiotics are commonly prescribed during pregnancy to treat bacterial infections. However, certain antibiotics are known to harm unborn babies and cause side effects like stained teeth or slow bone growth. Therefore, it is important to know which antibiotics are safe and which ones to avoid.

Tetracyclines

Tetracyclines, such as tetracycline, are not recommended during any stage of pregnancy as they are known to harm unborn babies. They can bind to calcium in the baby's bones and teeth, causing permanent yellow or grey discoloration. Tetracyclines may only be used in very rare situations, such as life-threatening infections to the mother and baby.

Fluoroquinolones

Fluoroquinolones, including ciprofloxacin (Cipro), levofloxacin (Levaquin), and moxifloxacin (Avelox), are not often used during pregnancy due to their risk of causing birth defects. They may harm a baby's developing heart, kidneys, or brain. These antibiotics are only used if there are no alternative treatment options available.

Metronidazole

Metronidazole (Flagyl) is an antibiotic used for certain infections, such as bacterial vaginosis. While it may be safe during the second and third trimesters, its use in the first trimester is linked to an increased risk of premature birth and miscarriage. Vaginal metronidazole is not recommended during any stage of pregnancy as it can cause congenital hydrocephalus, a life-threatening buildup of fluid in the baby's brain.

Nitrofurantoin

Nitrofurantoin (Macrobid, Macrodantin) is commonly used to treat urinary tract infections (UTIs). However, its safety during early pregnancy is unclear. Some studies have reported higher rates of birth defects when nitrofurantoin is taken in the first trimester, while others have found no link. Therefore, it is recommended to avoid nitrofurantoin in early pregnancy if possible.

Sulfamethoxazole/trimethoprim

Sulfamethoxazole/trimethoprim (Bactrim) has conflicting data on its safety in early pregnancy. Taking this antibiotic in the first trimester is linked to an increased risk of cleft palate, heart defects, and neural tube defects like spina bifida. It is generally avoided unless necessary, as it blocks folic acid, which is crucial for the healthy development of the unborn baby.

Other antibiotics that are generally avoided during pregnancy include clarithromycin, which may cause narrowing of the opening to the baby's stomach and folding of the intestines, and clindamycin, which is linked to infections in the baby and low birth weights when used vaginally.

Reasons for antibiotics during pregnancy

Antibiotics are often prescribed to treat bacterial infections during pregnancy. While no medication is 100% free of possible side effects, many antibiotics are considered safe for pregnant women. Here are some reasons why antibiotics may be necessary during pregnancy:

To Prevent and Treat Infections

Pregnant people are more susceptible to infections due to changes in their bodies, and these infections can be dangerous and even life-threatening for both the parent and the baby. Examples of common bacterial infections during pregnancy include urinary tract infections (UTIs), group B strep, gallbladder infections, and placenta and amniotic fluid infections. Antibiotics are the only effective treatment for bacterial infections, and leaving these infections untreated can have severe consequences.

To Reduce Risk of Miscarriage and Preterm Labour

Untreated infections during pregnancy can increase the risk of miscarriage and preterm labour. Antibiotics help address this risk by treating the underlying infection.

To Prevent Group B Streptococcus (GBS)

If a pregnant person tests positive for Group B streptococcus (GBS), a type of bacteria, they will typically be treated with intravenous (IV) antibiotics during labour. GBS can be passed on to the baby and potentially cause meningitis, pneumonia, or sepsis. Antibiotic treatment helps reduce this risk.

To Prevent Infections After Premature Rupture of Membranes

If a person's water breaks prematurely, especially before 34 weeks, antibiotic treatment can help prevent infections from reaching the baby before delivery.

To Treat Vaginal Infections

Metronidazole, while not an antibiotic, is often used to treat vaginal infections such as trichomoniasis and bacterial vaginosis.

While antibiotics are important for treating infections during pregnancy, it's crucial to use them only when necessary and under the guidance of a healthcare provider. Overuse of antibiotics can lead to antibiotic resistance, making it harder to treat infections effectively. Additionally, some antibiotics may have potential side effects or risks for the developing baby, so healthcare providers will carefully consider the benefits and risks of each medication.

Things to consider when taking antibiotics during pregnancy

Antibiotics are often prescribed to treat bacterial infections during pregnancy. While many antibiotics are considered safe for use during pregnancy, it is important to carefully consider the potential risks and benefits before taking any medication. Here are some things to keep in mind:

• Consult with a healthcare professional: Discuss any medications you are taking with your doctor or healthcare provider. They will be able to advise you on the safest option for you and your baby, considering factors such as the type of infection, dosage, and duration of treatment.
• Follow instructions: It is important to take antibiotics exactly as directed by your doctor. Take the medication for the full duration prescribed, even if you start to feel better. This helps prevent antibiotic resistance and ensures the infection is fully treated.
• Be aware of potential side effects: Antibiotics can sometimes cause side effects, such as allergic reactions or stomach and intestinal issues. Be mindful of any symptoms you experience while taking antibiotics and consult your doctor if you have any concerns.
• Understand the risks of untreated infections: Untreated infections during pregnancy can pose serious risks to both the mother and the baby, including miscarriage, preterm labour, and life-threatening illnesses. Weighing these risks against the potential side effects of antibiotics will help guide your decision-making.
• Consider alternatives: For minor conditions, such as the common cold, your doctor may recommend alternative treatments or over-the-counter medications that are safe for use during pregnancy. Self-care practices, such as gargling with warm salt water, can also be helpful.
• Be cautious in the first trimester: The first trimester is a critical period for fetal development, so extra caution is advised when taking any medications during this time. Consult your doctor about the safest options and follow their recommendations.
• Monitor your health: If you experience new or worsening symptoms, or if your infection is not improving, be sure to contact your healthcare provider. They can help determine the best course of action and rule out more serious conditions.

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