Long term impact of pre-incision antibiotics on babies born by caesarean section

Assorted images of babies and children and mother

In the UK, around one in three babies are born by caesarean section. In 2011, there was a change in the national guidance on caesarean section, recommending switching from giving preventative antibiotics after the umbilical cord is cut to giving antibiotics before the operation to further reduce the risk of infection, such as wound infection, in mothers. There are no known short-term health harms to the baby or their mother having these antibiotics around the time of the birth.

There is, however, growing evidence of the role of the human microbiome (different microbes that live in and on our body) in health and disease. Antibiotics given around the time of birth alter the gut microbiome of babies, which may impact on the development of the child’s immune system and increase susceptibility to allergic and other diseases in later life.

This research project investigated if this change in the national recommendation regarding the timing of preventative antibiotics had any long term impact on children born by caesarean section. It analysed anonymised data from several sources, including two UK primary care databases and hospital episode statistics database for England.



This study was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment (HTA) programme (project reference 16/150/01). The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care.

The project findings have now been published and can be found here:

Sumilo D, Nirantharakumar K, Willis BH, Rudge GM, Martin J, Gokhale K, et al. Long-term impact of pre-incision antibiotics on children born by caesarean section: a longitudinal study based on UK electronic health recordsHealth Technol Assess 2022;26(30).