At birth, newborns are endowed with maternal antibodies. igg production normally begins at the age of two months. a delay in recovery from this physiological hypogammaglobulinemia between the 3rd and the 6th month of life, and of recovery period between 18 and 36 months defines transient newborn hypogammaglobulinemia. [https://orcid.org/0000-0002-0736-9199]