The Malaghan Institute of Medical Research, in Wellington. Photo / Supplied
The Malaghan Institute of Medical Research, in Wellington. Photo / Supplied
Children whose mothers take antibiotics during pregnancy are at higher risk of developing asthma, a New Zealand-led review has found.
A team from Wellington's Malaghan Institute of Medical Research assessed results from 27 studies conducted over the past 20 years.
Malaghan Institute Postdoctoral fellow Dr Alissa Cait, who led the study, said there was a "statistically significant" increase in the risk of developing wheeze, asthma, dermatitis or food allergies if antibiotics had been used during pregnancy.
The results, published in May in the Allergy, were consistent regardless of which trimester the antibiotics were prescribed, and were true for all antibiotic classes except cephalosporins.
Cait said the findings could add another factor to consider when prescribing antibiotics in pregnancy.
"I don't think I would ever recommend that if a woman needed antibiotics that you wouldn't give her antibiotics," she said.
"But I think there could maybe be just a little bit more weighing of pros and cons ... just giving a bit more weight to the drawbacks of antibiotics and weighing that up when making a prescription."
The study was led by Malaghan Institute Postdoctoral fellow Dr Alissa Cait. Photo / Supplied
While the results were significant, Cait said they are also limited by the types of studies that have been undertaken.
"We found that the studies looking at this topic weren't necessarily representative of the wider population, so were difficult to estimate the true effect of these antibiotics."
She said the most effective and accurate studies are randomised and placebo-controlled, which is often not possible in research on humans.
"What we did was look at women who had received antibiotics during pregnancy because they needed them, and what was the outcome in the offspring," she said.
"The limitation of that is that we're really only looking at a correlation. There could be other explanations for why they develop allergic disease.
"One of the studies we looked at, they hypothesised that it wasn't really about the antibiotics themselves, but the mother's propensity for getting sick – if a mother was more likely to require antibiotics."
For this reason, Cait recommends further research in the field before any recommendations are made.
It also opens up interesting questions about why this phenomenon occurs, the area which she is most interested in investigating.
"I'm really interested in understanding that mechanism – how could it be that a pregnant woman taking antibiotics could five years later make that baby more susceptible to developing disease?"
"I think it probably has something to do with the way antibiotics affect the microbiome, and the way microbiomes are passed from the mother to the infant and then the way those microbiomes interact with the immune system and the developing immune system."
"So that's really what I'd want to work on next, and where I think the most interesting part of this question lies."
