Arterial Blood Gases. Test Overview. An arterial blood gas (ABG) test measures the acidity (pH) and the levels of oxygen and carbon dioxide in the blood from an artery. This test is used to check how well your lungs are able to move oxygen into the blood and remove carbon dioxide from the blood.
How Often the Test Is Done During Your Pregnancy. Your doctor may use the Doppler often to listen to your baby's heartbeat during routine checkups, starting at about 8 to 10 weeks. Handheld Dopplers will not work quite this early.
Equipment for Hearing the Fetal Heartbeat. The way we listen to a heartbeat is by using some equipment. I have in front of me here something that used to be used prior to the electronic age. This is called a Fetal Stethoscope.ometimes youâll hear a heart beat a little bit slower, sometimes you might hear a heart beat that goes much faster. These can be very normal and are not necessarily signs of a problem. When the baby is moving a lot, the babyâs heart rate might go up to as high as 180, 190.