Rh factor

American  

[ahr-eych fak-ter] / ˈɑrˈeɪtʃ ˌfæk tər /

noun

Physiology.

1. an inherited antigen found on the red blood cells of most people and certain other primates: those with this antigen are Rh positive while those lacking it are Rh negative, the determination of which is especially important when assessing blood-type compatibility for transfusions and pregnancy.

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Rh factor British  

noun

1. Full name: rhesus factor.  an agglutinogen commonly found in human blood: it may cause a haemolytic reaction, esp during pregnancy or following transfusion of blood that does not contain this agglutinogen See also Rh positive Rh negative

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Rh factor Scientific  

/ är′āch′ /

1. Any of several antigens present on the surface of red blood cells in most humans. People with Rh factors are classified as having a blood type that is Rh positive, while people who lack the antigen are said to be Rh negative and can produce powerful antibodies that destroy red blood cells if given a blood transfusion from an Rh–positive donor. A woman who is Rh negative and is pregnant with an Rh–positive fetus can produce antibodies that are life threatening to the fetus.

2. See Note at blood type

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Rh factor Cultural  

1. Any of several substances found on the surface of red blood cells in persons.

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An Rh-negative woman who gives birth to an Rh-positive baby may develop antibodies to the Rh factor during her first pregnancy. These antibodies may cause a disorder in Rh-positive babies conceived afterward that could result in the death of the infant if the condition is not recognized and treated.

Etymology

Origin of Rh factor

First recorded in 1940–45; so called because first found in the blood of rhesus monkeys

Example Sentences

In addition, red blood cells may have a protein called Rh factor.

From Los Angeles Times • Jul. 9, 2020

In 1937, Landsteiner and Alexander Wiener identified another essential feature of blood, the Rh factor, which explained blood incompatibilities between certain mothers and fetuses—a leading cause of stillbirths at the time.

From The New Yorker • Jan. 7, 2019

The allele for Rh factor comes in two forms: Rh+ and Rh−.

From Textbooks • Jan. 1, 2018

Looking at just the Rh factor, the team found that diabetes risk was the same whether or a not a woman was Rh positive or Rh negative.

From US News • Dec. 18, 2014

It's a wise child that knows his own father, but henceforth the Rh* factor will make it easier to establish paternity.

From Time Magazine Archive