An ultrasound examination is a non-invasive imaging study. The transducer (a small, hand-held instrument) produces sound waves to create a picture based on the density of the body tissues.

The ultrasound exam can be used to identify the gestational age of the fetus and whether the level of growth is appropriate,  assess the number of babies in the pregnancy, evaluate the placental structure, location and blood flow, and - most importantly - it allows a physical examination of the fetus. It is this complete evaluation of the fetus that allows the most appropriate treatments to be undertaken. 

A fetal MRI (magnetic resonance imaging) is another imaging test that offers physicians information about anatomic structures. This test does not use ionizing radiation to obtain the images, rather a magnetic field is used to create the pictures for evaluation. It is safe for pregnant woman and fetuses during the second and third trimesters.  

The MRI images can supplement the information obtained from the fetal ultrasound and can provide additional information regarding the fetal brain that can not be obtained from ultrasound, as well as information about other fetal anatomic structures that may guide care for the baby after delivery.

A fetal echocardiogram is an ultrasound specifically looking at the unborn baby's heart structure and function. The fetal echocardiogram is performed using similar equipment as that used for the detailed ultrasound of the whole baby, but more specialized pictures and information are obtained of the baby's heart. 

The fetal heart evaluation may be very important to help physicians prepare and plan for infant’s delivery and for any special interventions needed.  It is also important with many different types of birth defects other than heart defects to assess the heart’s function and determine appropriate treatment or fetal therapies that may be needed.

An amniocentesis is a prenatal test that allows information about the baby to be obtained from the amniotic fluid. This test can be done any time after the 15th week of gestation. While watching with ultrasound, a thin needle is guided through the mother's abdominal wall into a pocket of amniotic fluid located in the uterus. The amniotic fluid removed can be sent for testing depending on what is indicated. Amniocentesis may provide important information about the fetal chromosomes in addition to many other tests which can be run if indicated.

Chorionic villus sampling is a prenatal test performed between the 10th and 13th week of the pregnancy. It can be performed with a needle through the abdomen, or through the cervix using a small catheter (tiny tube). This is also done under direct ultrasound guidance. A small amount of tissue from the placenta is removed and sent to the lab for evaluation of chromosomes, or for specific genetic tests.

Fetal blood sampling (cordocentesis) can be performed in rare situations where fetal blood is required to evaluate the fetus. Medication can be administered and fetal blood transfusions can be performed when needed for treatment of the unborn baby.