Is It Safe To Take Antibiotics During Pregnancy?

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Medicines that are used to treat or prevent bacterial infection are called antibiotics. These drugs help fight infection either by killing the bacteria (bactericidal) or restricting its growth and multiplication (bacteriostatic) (1).

Women may get an antibiotic prescription during pregnancy to treat or prevent potential bacterial infections. However, maternal exposure to certain antibiotics can have possible adverse effects on unborn babies.

Seek medical consultation to choose pregnancy-safe antibiotics in a safe dosage and duration of treatment.

Read this article to know more about safe antibiotics and harmful antibiotics in pregnancy and the precautions that you need to observe to avoid antibiotic toxicity and adverse events while pregnant.

Why You May Need Antibiotics During Pregnancy?

Urinary tract infections and sexually transmitted infections are the most common bacterial infections in pregnancy. You may have to undergo antibiotic treatment if you have any of these infections (2) (3).

A requirement for antibiotic therapy in pregnancy can be due to the following situations.

  • Urinary tract infection in pregnancy can be caused by Escherichia coli bacteria, which are resistant to ampicillin and often require the prescription of antibiotics, such as cephalexin, sulfisoxazole, or nitrofurantoin.
  • All pregnant women are screened for asymptomatic bacteriuria (bacteria in the urine), and prophylactic antibiotic treatment is initiated to avoid infections such as cystitis and pyelonephritis. You may make regular prenatal follow up to identify bacteriuria. This could help prevent the use of more potent antibiotics for treatment (3) (4).
  • Antibiotic therapy is unavoidable in certain medical conditions such as severe bacterial infection, blood infection, and sepsis, which is the body’s response to infection (5).

Untreated urinary tract infections and sexually transmitted infections can cause severe morbidities, such as spontaneous abortion, preterm birth, and low birth weight during pregnancy, and also be life-threatening in some cases.

Is It Safe To Take Antibiotics When Pregnant?

Some antibiotics are safe to take in pregnancy, while a few may cause potential adverse effects in pregnant mothers and unborn babies. The safety of antibiotics may vary depending on the type of antibiotic, dosage, duration of treatment, gestational age, and the mother’s health condition.

Therefore, always consult a doctor for safe antibiotic use and to avoid any adverse events.

Also, physiological changes in pregnancy can change the body’s metabolism and excretion and affect plasma levels of antibiotics.  Thus, the dosage for non-pregnant women won’t be suitable for pregnant women.

Your healthcare provider can choose the safest antibiotic with a safe dosage and duration. If you have any concerns and queries, then you may openly discuss it with your doctor. You may also inform the doctor about any antibiotic allergies, such as penicillin allergies, that you had in the past.

List Of Safe Antibiotics During Pregnancy

The following antibiotics are considered safe in pregnancy (3) (6) (7).

  • Penicillins (amoxicillin, ampicillin) are shown to be safe in pregnant and breastfeeding mothers.
  • Cephalosporins (cefaclor, cephalexin) is a group of antibiotics that is well tolerated in pregnancy.
  • Erythromycin (Erymax, Erythrocin, Erythroped, Erythroped A) is the only macrolide group of antibiotics that is safe during pregnancy and lactation.
  • Clindamycin
  • Beta‐lactams
  • Vancomycin
  • Nitrofurantoin
  • Metronidazole
  • Fosfomycin

Safe Antibiotics For UTI During Pregnancy

Urinary tract infections in pregnancy are treated with antibiotics that are safe for pregnant women and the fetus. Ampicillin was one of the safest drugs of choice in the past, but E.coli’s resistance to ampicillin in recent years has led to the use of other antibiotics.

The following antibiotics are prescribed for the treatment of urinary tract infections in pregnancy.

  • Monrol (fosfomycin) single-dose therapy is one of the newest approaches Cephalosporins
  • Sulfonamides are given in the first and second trimesters. Taking them in the third trimester may cause the baby to develop kernicterus (brain damage from jaundice).
  • Nitrofurantoin (Macrodantin) use is limited to severe infection with high bacteriuria due to its side effects.
  • Cephalosporins

Sulfonamides and nitrofurantoin are prescribed in the first trimester when other treatments are not effective against infection since it has a potential risk of causing birth defects (8) (9).

Which Antibiotics To Avoid During Pregnancy?

The following antibiotics should be avoided during pregnancy due to their teratogenic effects (harmful effects due to exposure to toxic substances during pregnancy) (10):

  • Chloramphenicol: This may cause jaundice and gray baby syndrome, particularly if taken near the due date.
  • Tetracyclines: These may cause teeth discoloration (yellow or brown color) in babies and are not usually recommended for pregnant women.
  • Fluoroquinolone (ciprofloxacin, levofloxacin): Fluoroquinolone antibiotics could damage the baby’s muscle and bone growth. It may often result in aortic tears that can cause fatal bleeding. It is not recommended for people with cardiovascular diseases. Fluoroquinolones may also cause joint pain and nerve damage in the mother (11).

Precautions To Take While Having Antibiotics In Pregnancy

Taking the following precautions may help reduce antibiotic toxicity and side effects in expected mothers and their unborn babies.

  • Do not use antibiotics without prescription during pregnancy. Inappropriate choice of antibiotic and dosage could cause toxic effects and also increase the risk of antibiotic resistance.
  • Use an antibiotic when it is required. Severe infections require antibiotic treatment during pregnancy.
  • Consult the doctor each time you have infections during pregnancy. Let the doctor decide if you require antibiotic treatment. Taking previous medications may not be suitable and safe in all weeks of gestation.
  • Do not use antibiotics for influenza and the common cold. Antibiotics are not effective against viral illnesses.
  • You may follow your gynecologist’s advice to protect yourself from infections during pregnancy. Exposure to antibiotics can be harmful to babies, especially during the first trimester, when they are developing tissues and organ systems.
  • Always ensure that you are taking pregnancy-safe medications. Get prescriptions after informing your doctor that you are pregnant, especially in the first trimester, since it may go unnoticed.
  • Follow the prescription as recommended to avoid antibiotic resistance.

Antibiotics can be available over-the-counter in some countries. However, over-the-counter medications may result in pregnancy complications, and getting a doctor’s prescription is advisable.

Frequently Asked Questions

1. Do antibiotics cause birth defects?

A few antibiotics may lead to birth defects. Taking antibiotics such as nitrofurantoin and trimethoprim-sulfamethoxazole (TMP/SMX) for the treatment of urinary tract infections (UTIs) in pregnancy may result in birth defects.

Considering the adverse effects of antibiotics on developing babies, the American College of Obstetricians and Gynecologists (ACOG) suggests avoiding the use of antibiotics in early pregnancy (9). Antibiotic treatment is usually recommended during pregnancy when it is an absolute need, and safe pregnancy antibiotics are commonly prescribed for expectant mothers. 

2. Can antibiotics cause miscarriage? 

Some studies have shown that certain types of antibiotics may increase the risk for miscarriage. Z-pak or azithromycin had shown to increase the miscarriage risk up to 65% if used during pregnancy (12). Spontaneous miscarriage risk is enhanced with the use of tetracyclines and quinolones.

Penicillins and cephalosporin are shown to be safe in pregnant women. More randomized controlled studies are required to determine the exact rate of miscarriage in antibiotic treatments during pregnancy. 

3. Can taking antibiotics while pregnant harm the baby?

Some antibiotics are associated with birth defects and teeth damage in unborn babies. The risk of oral cleft formation increases in babies of women who were exposed to amoxicillin in early gestational weeks (13). Yellow discoloration of teeth is seen when tetracycline is taken in early pregnancy.

Some studies have shown that antibiotics could change maternal and fetoplacentalmicrobiota (14). Microflora can be disturbed while taking medicines for preventing infections. However, this is not associated with any severe side effects.

4. Can antibiotics in pregnancy cause autism?

Some studies have shown a small increase in autism spectrum disorders (ASD) among babies exposed to antibiotics in fetal life (15). The relation between prenatal antibiotic exposure and autism requires more randomized controlled trials since many other studies do not support this hypothesis (16).

The subsequent development of ASD, due to early life antibiotic exposure, requires detailed study. These effects can be variable depending on the type, dosage, and duration of prenatal antibiotic exposure.

Although antibiotics are known to cause some adverse events in pregnant mothers and unborn babies, these are required to manage severe bacterial infections. Sometimes, the infections could cause more damage to the baby or increase the risk of sepsis and miscarriage in mothers than antibiotics.

Not all antibiotics are harmful in pregnancy. You may consult a doctor for treating infections in pregnancy with pregnancy-safe antibiotics. Always seek medical care if you suspect STIs or UTIs in pregnancy. Delaying care could lead to complications and require you to take high doses of potent medications for a long duration.


1. Antibiotic Prescribing and Use in Doctor’s Offices; The Centers for Disease Control and Prevention
2. John E. Delzellet al., Urinary Tract Infections During Pregnancy; The American Academy of Family Physicians (2002).
3. P. Brandon Bookstaveret al., A Review of Antibiotic Use in Pregnancy; American College of Clinical Pharmacy (ACCP) (2015).
4. Sharon Scott Morey, ACOG Releases Report on Antimicrobial Therapy in Pregnancy; The American Academy of Family Physicians (1998).
5. Be Antibiotics Aware: Smart Use, Best Care; TheCenters for Disease Control and Prevention
6. Antibiotics; National Health Service
7. Antibiotic Use During Pregnancy and Lactation; The American Academy of Family Physicians
8. Antibiotics Dispensed to Privately Insured Pregnant Women with Urinary Tract Infections — United States, 2014; TheCenters for Disease Control and Prevention
9. Antibiotic Treatments for Urinary Tract Infections Are Commonly Prescribed To Pregnant Women; TheCenters for Disease Control and Prevention
10. Ciprofloxacin Use by Pregnant and Lactating Women; The Food and Drug Administration (FDA or USFDA)
11. FDA warns about increased risk of ruptures or tears in the aorta blood vessel with fluoroquinolone antibiotics in certain patients; The Food and Drug Administration (FDA or USFDA)
12. Part two: Can taking antibiotics during pregnancy increase risk of miscarriage?; The University of Texas Southwestern Medical Center
13. Kueiyu Joshua Linet al., Maternal Exposure to Amoxicillin and the Risk of Oral Clefts; The United States National Library of Medicine
14. Amir A. Kuperman and OmryKoren; Antibiotic use during pregnancy: how bad is it?; BMC Medicine (2016).
15. Amani F. Hamadet al., Prenatal antibiotics exposure and the risk of autism spectrum disorders: A population-based cohort study;PLoS One (2019).
16. Jan Lukasik et al., Early Life Exposure to Antibiotics and Autism Spectrum Disorders: A Systematic Review; Journal of Autism and Developmental Disorders (2019).

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