Is Ultrasound Overused In Pregnancy?
Originally used only in high risk
pregnancies, ultrasound is now offered
routinely many times throughout
pregnancy. Routine use is now
officially recommended one time only at
16 to 18 weeks. Diagnostic ultrasound
is useful for high risk or complicated
pregnancies.
During an ultrasound examination, high
frequency sound waves scan the mother's
abdomen and then reflect the fetus and
placenta on a video screen. Ultrasound
technology has advanced to the point
where it can show genetic as well as
structural fetal abnormalities.
Research shows that routine ultrasound
does not improve the outcome for the
baby. Long term risks for the baby are
unknown and have not been adequately
studied. As with other technologies
like electronic fetal monitoring,
ultrasound was in widespread use before
its risk versus benefit ratio could be
studied.
Routine Ultrasound
- Performed on healthy low risk women.
- Identifies structural abnormalities of
baby.
- Predicts delivery date within two weeks
89 percent of the time.
- Shows placental position but 90 percent
of low lying placentas on first
ultrasound move into normal position by
birth.
- Down's syndrome can now be detected
with about 75 percent accuracy,
especially when combined with blood
tests.
Diagnostic Ultrasound
- Takes longer and answers specific
questions.
- Useful for high risk pregnancies in
women with diabetes, high blood
pressure and other complications.
- Required for amniocentesis (taking
sample of amniotic fluid to test for
genetic testing).
- Necessary when complications of
pregnancy develop such as tubal
pregnancy, suspected twins, abnormal
bleeding, too much or too little
waters, and baby small or growing too
slowly.
- To check for abnormal placental
position.
How To Avoid Unnecessary Ultrasounds
- Keep records of periods before
pregnancy to get accurate birth date.
- Have doctor or midwife check baby's
position manually and baby's heart with
fetal stethoscope.
- Decide how important it is to know
fetal abnormalities in advance.
- Ask your doctor what information is
expected from ultrasound and will that
information change my care. Could other
tests find out the same information?.
- No need for more than one ultrasound in
a normal low risk pregnancy.
