Immune System
A baby's immune system is not fully developed until he/she is about six months-old. The placenta functions as a selective maternal-fetal barrier against transmission of microbes. However, insufficiency in this function may still cause mother-to-child transmission of infectious diseases.
Also, maternal IgG antibodies cross the placenta, giving the fetus passive immunity against diseases for which the mother has antibodies. This transfer of antibodies begin as early as the 20th week of gestational age, and certainly by the 24th week. IgG antibodies are the smallest, but most abundant antibodies, making up 75-80% of all the antibodies in the body.
Read more about this topic: Fetus
Famous quotes related to immune system:
“The moral immune system of this country has been weakened and attacked, and the AIDS virus is the perfect metaphor for it. The malignant neglect of the last twelve years has led to breakdown of our country’s immune system, environmentally, culturally, politically, spiritually and physically.”
—Barbra Streisand (b. 1942)