FIRST-BORN children are more likely to suffer allergies than younger siblings, a study has revealed.
Researchers found multiple births boost the immune system in the womb, which is then transferred to the baby. So second and third children are less likely to suffer hay fever or food allergies.
Scientists surveyed 13,000 children aged seven to 15 asking parents the order of their children and what allergies they had.
Four per cent of firstborns had conjunctivitis, rhinitis and food allergies, against 3.5 per cent of second and 2.6 per cent of third children.
Dr Takashi Kusunoki, who led the study for the Shiga Medical Center for Children and Kyoto University in Japan, said: “Individuals with increased birth order have a smaller risk of allergy.”
Scientists also cite the “hygiene hypothesis”, where nervous first-time parents over-sterilise. Subsequent children build a stronger immune system after being exposed to more germs in the home.