rePost::How Your Birth Order Can Influence Who You Are

Health
Birth order can also have an impact in unexpected areas.
For example, researchers found that firstborn children have a greater difficulty absorbing sugars into the blood and have a higher daytime blood pressure than later born children. Firstborns, therefore, may be at a greater risk of metabolic and cardiovascular diseases in adult life. They surmise that this difference may be attributable to physical changes in the mother’s uterus during her first pregnancy.
Japanese researchers have also discovered that first-borns may be more susceptible to food allergies.
First-borns may also be predisposed, for unknown reasons, to high-functioning autism (or what used to be called Asperger’s syndrome). It may have something to do with birth stoppage, obstetric complications, or immunological processes — but scientists aren’t really sure. Relatedly, closely spaced pregnancies have been linked to autism.
Researchers have also found a decreasing risk with increasing birth order for certain childhood cancers (but the opposite for acute myeloid leukemia). In terms of an explanation, the researchers write, “It is possible that firstborn children have higher estrogen exposures that may contribute to greater risk of cancer than later born children. Estrogen levels in maternal and umbilical cord blood samples are somewhat greater in first pregnancies compared with second or third pregnancies.”
Also, children with older siblings are more likely to experience respiratory symptoms at four years of age. One possible explanation is that children with older siblings have more exposure to respiratory infections at an early age than oldest or only children.
via How Your Birth Order Can Influence Who You Are.