Immune system influenced in the womb

A pregnant woman's body undergoes considerable physiological changes that need to be monitored very carefully to ensure the well being of the mother and child. The environment in the womb may play a role in deciding the susceptibility of infants to asthma and allergies in childhood. Previous research has found that first-born children or those who have few siblings are more likely to have asthma and allergies than those with many siblings. Children with many siblings are more exposed to germs early on and develop stronger immune systems, while children who are first-born or only children do not receive this benefit.The researchers studied nearly 1,000 infants born on the Isle of Wight in England between 1989 and 1990. They tested the infant's umbilical cord blood for levels of immunoglobulin E (IgE), an antibody linked to allergies. They noted that first-born children were twice as likely to have a higher concentration of IgE, with 16% of first-born children having a certain level of IgE compared with only 8% of third-born children. They also conducted an allergy test on the children at age four and found that those with higher levels of IgE did show a significant increase in allergic reactions. The findings suggest that the environment in the womb does play an important role in the infant's developing immune system. The cord IgE is reduced in pregnancies with higher order, however, they did not find a direct correlation between birth order and skin allergic reactions.