London: Smoking during pregnancy can triple the baby`s chance of developing meningitis, researchers warn.
Children exposed to smoke from a parent`s cigarettes at home are also twice as likely to have the deadly illness.
Researchers believe that passive smoking gradually weakens children`s immune system making them more susceptible to the illness, the `Daily Mail` reported.
Researchers from the University of Nottingham analysed 18 studies which looked at the link between passive smoking and meningitis.
Meningitis is caused by an infection of the protective membranes surrounding the brain and spinal cord and if not treated quickly it can cause brain and nerve damage.
Symptoms include severe headache, a rash, vomiting, high temperature and a dislike of bright lights.
They found that children exposed to second hand smoke in the home were more than twice as likely to get the illness.
The under-fives were even more vulnerable - they were found to be two and a half times more at risk.
And children whose mothers smoked during pregnancy were three times more likely to get meningitis, the study published in journal BMC Public Health found.
"We estimate that an extra 630 cases of childhood invasive meningococcal disease every year are directly attributable to second-hand smoke in the UK alone," lead researcher Dr Rachael Murray said.
"While we cannot be sure exactly how tobacco smoke is affecting these children, the findings from this study highlight consistent evidence of the further harms of smoking around children and during pregnancy, and thus parents and family members should be encouraged to not smoke in the home or around children," Murray said.
In recent years a number of studies have shown massive smoking increases a child`s risk of meningitis but this is one of the first to show the link between a mother smoking during pregnancy.
The findings of this latest study imply this process begins while the baby is still in the womb.
Experts think that smoke contains bacteria which gradually weaken children`s immune systems.