An ultrasound is a diagnostic test that is conducted throughout a pregnancy, mainly to identify any health issues with the baby. It involves a machine that uses high-frequency waves that are transmitted through the abdominal wall to produce an image of the abdomen and pelvis. This is done using a transducer that is moved over the abdomen and pelvic area.

The first ultrasound in a pregnancy will probably be done some time around week 12 , unless there are reasons that your doctor feels may justify an earlier test.

Reasons for an Ultrasound

This prenatal test is used throughout a pregnancy to:

* Identify a pregnancy
* Identify a fetal heartbeat in early pregnancy
* Date the pregnancy
* Identify any congenital problems with the baby
* Estimate the size of the baby
* Identify the gender of the baby
* Identify a multiple pregnancy (such as twins or triplets)
* Determine the cause of early pregnancy bleeding
* Analyze the placenta
* Guide prenatal tests such as chorionic villus sampling or amniocentesis
* Identify reasons for lack of fetal heartbeat or movement
* Measure amniotic fluid

Before Having an Abdominal Ultrasound

Usually when an ultrasound is booked, the technician will inform you that you will need to have a full bladder. Most likely you will have to drink about 4 to 6 glasses of water (NOT milk!) about an hour before the test. This will push the bowel out of the way, and will give a better view of the uterus. Later on in pregnancy, a full bladder is not necessary.

The exam usually lasts about a half hour, and can be a little uncomfortable as the transducer is firmly pressed on your full bladder!

3D Ultrasound

Technology is a wonderful thing! Nowadays, a 3D ultrasound is available, which generates a 3D image of the baby! These tests work a little differently that regular 2 dimensional version by sending sound waves at different angles.

Transvaginal Ultrasound

A transvaginal ultrasound involves using a wand-shaped transducer that is placed inside the vagina to look at the uterus, fallopian tubes and ovaries. It is generally not used in pregnancy, but used to identify any fertility issues a woman who may be trying to get pregnant may have. It can also identify if any tissue has remained following a miscarriage .

Safety of Ultrasound

This prenatal test is safe for you and your baby because no harmful rays are used, such as those used in an x-ray. Sound waves are used instead to allow for visualization.