Rh Blood Group

The Rh blood group was named after the rhesus monkey in which it was first studied. In humans, this group includes several Rh antigens (factors). The most important of these is antigen D: however, if any of the antigen D and other Rh antigens are present on the red blood cell membranes, the blood is said to be Rh-positive. Conversely, if the red blood cells lack the Rh antigens, the blood is called Rh-negative.

As in the case of antigens A and B, the presence (or absence) of Rh antigens is an inherited trait. Unlike anti-A and anti-B, antibodies for Rh (anti-Rh) do not appear spontaneously. Instead, they form only in Rh-negative persons in response to special stimulation.

If an Rh-negative person receives a transfusion of Rh-positive blood, the recipient's antibody-producing cells are stimulated by the presence of the Rh antigens

What is the Rh blood group?

What are two ways that Rh incompatibility can arise?

Erythroblastosis fetalis is extremely rare today because obstetricians carefully track Rh status. An Rh- woman who might carry an Rh+ fetus is given an injection of a drug called RhoGAM. This is actually anti-Rh antibodies, which bind to and shield any Rh+ fetal cells that might contact the woman's cells, sensitizing her immune system. RhoGAM must be given within seventy-two hours of possible contact with Rh+ cells — such situations include giving birth, terminating a pregnancy, miscarrying, or undergoing amniocentesis (a prenatal test in which a needle is inserted into the uterus).

Blood Grouping

Cells from Rh-positive fetus enter woman's bloodstream

Rh-negative woman with Rh-positive fetus

Rh-negative woman and Rh-positive man conceive a child

Factor Pregnancy

Rh-negative woman with Rh-positive fetus

Cells from Rh-positive fetus enter woman's bloodstream

Rh-negative woman and Rh-positive man conceive a child

Woman becomes sensitized— antibodies ( +) form to fight Rh-positive red blood cells

In the next

Rh-positive pregnancy, maternal antibodies attack fetal red blood cells

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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Responses

  • joshua
    What are two ways that rh incompatibility can arise?
    5 years ago
  • robert
    What are two ways Rh incompatability can arise?
    3 years ago

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