Exposure to Rubella (German measles) during pregnancy
Most mothers born after the mid-1960s will have been immunized and over 90 per cent
of these will have acquired long-term immunity. A fair proportion of the rest will
have had the infection and acquired immunity that way.
If you get exposed to Rubella while pregnant and you are unsure whether you are immune
or not, you should see your doctor promptly to have a blood test to establish your
If you are immune, you cannot acquire the Rubella infection and therefore cannot
pass it on to the fetus.
For those mothers who are not immune to rubella
If you acquire a rubella infection during pregnancy, there is nothing that can be
done to influence what happens to the baby. Since most Rubella infections tend to
pass off more or less silently, if you have been exposed, a blood tests will be required
to confirm whether the infection has indeed been passed on to you.
Effects of Rubella infection on the fetus
Rubella infection of the baby in the womb could lead to what is called "Congenital
The earlier in pregnancy the infection is acquired, the more severe the features
of the syndrome. These may include some or all of the following:
· Enlargement of the spleen
· Heart disease
· A small head (microcephaly) together with mental retardation
· Thyroid dysfunction.
The syndrome could be so severe as to make the quality of life of the child quite
Most (over 70%) of babies will be affected, to varying degrees, if the mother acquires
the infection in the first 12 weeks of pregnancy.
Tests to identify whether a baby has been affected by Rubella
A test can be done to check whether a mother’s rubella infection has affected the
baby also. Unfortunately this can only be done and is only reliable after twenty
weeks of gestation.
A cord blood sample is taken and analyzed to establish whether the infection was
passed to the fetus. This procedure does carry a small but significant risk of killing
the fetus or provoking a miscarriage.