Antibiotics in Pregnancy Harm Baby's Immunity

Jacob Collyer-Smith Lifestyle Writer

A recent study1 from the Children’s Hospital of Philadelphia has revealed that antibiotic treatment during pregnancy may be harmful to the development of a baby’s immune system. The study suggests that antibiotic treatment denies the baby’s immune system exposure to pathogenic bacteria which is important in building resistance. 

The researchers also suggest that antibiotic treatment may also have a more direct impact on the child’s immune system, as blood tests reveal that white blood cell counts are reduced in babies exposed to antibiotics during gestation. This may be a result of the antibiotics killing beneficial bacteria which are vital to white blood cell regulation. One author of the study, Hitesh Deshmukh, commented on the significance of this finding, “At birth, newborns move from a largely sterile environment to one full of microorganisms. Animals and humans adapt to this new situation by ramping up the production of granulocytes (a type of white blood cell) within the first days of life.”

newborn baby sleeping
Antibiotics are necessary in many situations

Treatment with antibiotics also reduced the diversity of the gut microbiota (visit the Probiotics Learning Lab for further information) in both the mother and child which is detrimental to maintaining a healthy immune system.

Current medical guidelines are to treat ill newborns with antibiotics, even without proof of infection, as a precaution as it is difficult to determine if a baby is infected.

The authors of this latest study have urged clinicians to review antibiotic use, and take a longer-term viewpoint of the health of children.

We’d never suggest going against a doctor’s advice. Antibiotics are absolutely necessary in many situations and will continue to be a vital tool in modern medicine. However, many studies suggest that taking a probiotic during antibiotic treatment may help to keep the natural gut microbiota “topped up”, and help the body to recover quicker from antibiotic treatment.

For further reading on this subject check out our recent article on probiotics and antibiotic resistance. Our FAQ page on taking probiotics and antibiotics together, over in the Probiotics Learning Lab, may also be of interest.


  1. Deshmukh, H, et al. (2014) 'The microbiota regulates neutrophil homeostasis and host resistance to Escherichia coli K1 sepsis in neonatal mice'. Natural Medicine Journal, 20(5): 524-30
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