Should I have an early fetal ultrasound?
Introduction
This information will help you understand your choices, whether you
share in the decision-making process or rely on your doctor's or certified
nurse-midwife's recommendation.
Key points in making your decision
Consider the following as you decide whether to have an early
ultrasound, before 20 weeks of pregnancy:
- Fetal ultrasound is a safe and simple way to
look at your fetus. If your ultrasound doesn't show any problems, you may feel
more reassured and relaxed during your pregnancy.
- If you aren't
sure of your last menstrual period, an ultrasound can help confirm the age of
the fetus and predict your due date.
- If you have first trimester
bleeding, an ultrasound may be able to rule out a miscarriage and reassure you
that your fetus is okay.
- Ultrasound may raise concern about a
possible problem without necessarily offering a diagnosis. In such a case, you
will need to have other tests to confirm ultrasound findings.
- If
you are sure of your last menstrual period and don't have any risk factors for
birth defects, an ultrasound may not be necessary.
This information may not apply to you if your health professional
recommends that you have a fetal ultrasound. Your doctor or nurse-midwife may
recommend an ultrasound for a specific medical reason—if there is a need to
accurately date your pregnancy, if you are having unusual symptoms, or if you
have had abnormal results from another test.
Medical Information
What is a fetal ultrasound?
Fetal ultrasound uses reflected sound waves to provide an image
of a fetus and
placenta within the uterus. Fetal ultrasound is the
safest way to obtain information about the fetus, such as size and position.
A fetal ultrasound can be done as early as the fifth week of
pregnancy. During the test, a small handheld instrument called a transducer is
used to direct sound waves toward the body. A computer analyzes the sound waves
that are reflected back from structures inside the body and converts them into
an image. Fetal ultrasound can be done by moving the transducer across the
woman's abdomen (transabdominal) or by putting the transducer in her vagina
(transvaginal). After about the 11th week of pregnancy, almost all ultrasound
tests are done using the transabdominal method.
What information can a fetal ultrasound provide?
An ultrasound done before 20 weeks of pregnancy can give you
information about:
- Fetal condition, if vaginal bleeding or other symptoms of
miscarriage have raised concern.
- Fetal age and size (sex can often
be identified at around 20 weeks of pregnancy).
- The number of
fetuses present.
- Some types of birth defects, such as a defect of
the spinal cord (neural tube defect), heart, abdominal
organs, or brain.
- The condition of the
placenta and the amount of
amniotic fluid around a fetus.
Ultrasound may raise concern about a possible problem without
necessarily offering a definite diagnosis. In such a case, other tests are used
to confirm ultrasound findings.
What would I do with information from a fetal ultrasound?
A normal ultrasound does not guarantee a healthy child. However,
ultrasound results can give you useful information.
- If your ultrasound doesn't show any fetal
problems, you can feel more reassured and relaxed during your pregnancy.
- If you learn that you are carrying more than one fetus, you and
your health professional can plan ahead for a healthy pregnancy and delivery.
For more information, see the topic
Multiple Pregnancy: Twins or More.
- If you
find out that the fetus has a problem, you, your partner, and your health
professional can discuss your options. The first step may be to repeat the
ultrasound or have other tests that can confirm the results.
- Some problems are treatable soon after
the baby is born and may not seriously affect the baby's life. You may be able
to plan your delivery in a hospital that offers specialized care for sick
newborns.
- Some defects, such as certain types of
neural tube defects and
Down syndrome, may not be fatal but will affect the
baby for his or her entire life.
- Rarely, a defect is so severe that
the fetus may not survive the pregnancy or may die soon after birth.
- Sometimes a possible defect is suspected but
not confirmed, and the baby is born perfectly healthy.
The decision about what to do if you find out that you are
carrying a fetus with a severe defect is very personal. Some women who learn
that they are carrying a fetus with a serious defect choose the option of
ending the pregnancy with a therapeutic abortion. Others make plans for raising
a sick or disabled child.
What are the risks of fetal ultrasound?
Fetal ultrasound is a very safe test and does not seem to have
any risks. However, an abnormal ultrasound can cause a lot of stress and
anxiety. An ultrasound:
- Can show an unusual result that requires more
tests, such as another ultrasound or
amniocentesis, to confirm. In most cases, these
additional tests are normal. However, the additional tests may carry risks.
Amniocentesis has more risks than ultrasound, including a very small risk of
miscarriage.
- Can show an abnormality that disappears later in the
pregnancy.
- May indicate a serious problem when there isn't one. In
such a case, additional tests are needed before you can know that there is not
a problem. It can be very stressful while you wait for the results.
What are the risks of not having a fetal ultrasound?
If you don't have an ultrasound, there is a slight chance that
you may not find out until later in the pregnancy or delivery that:
- You are pregnant with more than one fetus.
- A birth defect is present. Rarely, a fetus has a birth defect that
is so serious that the fetus will die later in the pregnancy, during delivery,
or soon after birth. Some women would choose to end a severely affected
pregnancy rather than suffer a stillbirth or death of a newborn.
For more information, see the topic
Fetal Ultrasound.
Your Information
Your choices are:
- Have a fetal ultrasound.
- Do not
have a fetal ultrasound.
The decision about whether to have a fetal ultrasound takes into account
your personal feelings and the medical facts.
Fetal ultrasound
| Reasons to have a fetal ultrasound | Reasons not to have a fetal
ultrasound |
- You have had vaginal bleeding or
cramping, which are signs of a possible miscarriage or preterm labor.
- You're not sure of the date of your last menstrual period; your
health professional therefore needs an estimate of your fetus's
age.
- You have had a prenatal test that suggests a possible fetal
problem.
- You have risk factors for a birth defect that might be
detected by ultrasound.
Are there other reasons you might want to have a fetal
ultrasound?
|
- You haven't had any vaginal bleeding or
cramping, which are signs of a possible miscarriage or preterm
labor.
- You are sure of the date of your last menstrual period and
therefore your fetus's age.
- Prenatal tests do not suggest a
possible fetal problem.
- You have no risk factors for birth defects
that might be detected by ultrasound.
- You are only interested in
knowing the fetus's sex or having a picture or video of the fetus.
Are there other reasons you might not want to have a fetal
ultrasound?
|
These
personal stories may help you make your
decision.
Wise Health Decision
Use this worksheet to help you make your decision. After
completing it, you should have a better idea of how you feel about having a
fetal ultrasound. Discuss the worksheet with your health professional.
Circle the answer that best applies to you.
| I am comfortable with the idea of having a fetal
ultrasound. | Yes | No | Unsure |
| My doctor has recommended that I have an
ultrasound for medical reasons. | Yes | No | Unsure |
| I have no major risk factors for a fetal problem
but would feel better knowing that my fetus looks normal. | Yes | No | Unsure |
Use the following space to list any other important concerns you
have about this decision.
What is your overall impression?
Your answers in the above worksheet are meant to give you a
general idea of where you stand on this decision. You may have one overriding
reason for having or not having a fetal ultrasound.
Check the box below that represents your overall impression about
your decision.
|
Leaning toward having a fetal
ultrasound
| |
Leaning toward NOT having a fetal
ultrasound
|
Return to the topics:
Credits
| Author | Shannon Erstad, MBA/MPH |
| Editor | Kathleen M. Ariss, MS |
| Associate Editor | Pat Truman |
| Primary Medical Reviewer | Renée M. Crichlow, MD - Family Medicine |
| Specialist Medical Reviewer | Kirtly Jones, MD - Obstetrics and Gynecology |
| Last Updated | November 30, 2006 |
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