Your first ultrasound appointment! You'll probably go in with a mixture of excitement and concern, and you may have many questions, such as:
- How much can they see?
- Will they be able to tell me if it's a girl or boy?
- Will they be able to tell if anything's wrong?
- What if there is something wrong?
- Will they tell me everything I want to know at the visit, or will I have to wait?
- Why do I have to have a full bladder?
- How safe is ultrasound?
Most ultrasound screens are performed at about 18 to 20 weeks because this is an appropriate time for dating the pregnancy and evaluating baby's structures and organs. The heart is the last organ to develop, and development of two atria and two ventricles should be complete by 18 weeks from the first day of your last period.
Here, some of the words and phrases you'll come across during your ultrasound:
- Fetal biometry -- measurements of important structures that, when taken together, give an approximation of fetal gestational age
- Biparietal diameter -- measurement made between two points through the baby's head from about one ear to the other
- Abdominal circumference -- distance around the abdomen at about the level of the umbilicus
- Femur length -- length of the thighbone
Structures
Every ultrasound report done at 18 weeks and beyond will provide an interpretation of baby's:
- Brain
Examining the:
—Cerebral ventricles -- cavities filled with cerebrospinal fluid inside the brain
—Posterior fossa -- a depression on the interior back portion of the base of the skull
Looking for:
—Choroids plexus cysts, usually resolved by 28 weeks and rarely associated with chromosomal abnormality (If these cysts persist into the second trimester, suspicion is raised for a chromosomal defect known as Trisomy 18.)
- Face: Looking for clefts and symmetry
- Spine: Looking for completeness and an intact neural tube
- Heart: Looking for the presence of two atria and two ventricles
- Stomach: Looking at size and symmetry
- Kidneys: Looking at size and patency of the ureters to make sure that no obstruction is present
- Bladder: Observing the filling of the bladder and the outflow pathway
- Abdominal cord insertion
Looking at the area where the cord inserts into baby's abdomen, checking for completeness of the abdominal wall
- Cord vessels
- Arms and hands
- Legs and feet
- Genitals
- Amniotic fluid
