Measurements of Baby's Size
We carefully measure our infant research participants including each baby’s length, weight, head circumference, abdominal circumference and limb circumferences. In addition we use an instrument called a caliper to measure your baby’s skin fold thickness. This is done by gently pulling the skin up and placing the two pads on the tip of the calipers around the slightly pinched skin. We use calipers to measure the thickness of the skin folds in the arm, hip, back, and thigh areas of the body. We have performed these measurements on many infants and taking these measurements does not appear to cause any significant discomfort for the infants.
The “PEA POD” is a different technique for measuring the amount of fat in our infant research participants. It uses air to determine body fat. It just takes a few minutes to complete and is painless. The infants will lie in a special chamber, but are visible to at all times. He or she can lie awake or go to sleep, and can move around during the test. PEA POD does not involve any radiation and there are no dangers to your infant.
Maternal Body Composition/BODPOD
We measure our adult research participant’s body composition using a tape measure, skinfold calipers, and the BODPOD. The BODPOD machine uses air to determine body fat, just like the PEAPOD. This procedure takes just a few minutes to complete, is painless, and does not involve any radiation or danger.
Women in the CHOICE study and the Sleep in Pregnancy study will both wear continuous glucose monitors (CGMs) from DEXCOM for 3 days. The video below shows how these CGMs work, and will give you a look into what those 3 study days will be like. One difference between research based CGMs and personal CGMs, is that the CGM of the participant will be in blinded mode. You will not be able to see your glucose pattern until the end of the three days, and you will continue to take finger sticks to monitor your glucose levels. At the end of the three days, a member of the research team will show you the results of your CGM and answer any questions you may have.
Measurements of the Baby's Size/ Infant DXA
By the time our research infant participants reach 12 months of age, they no longer fit inside the PEA POD.Instead, we use a test called DXA, which stands for dual-energy X-ray absorptiometry, to measure body composition. In this test the babies are wrapped in a blanket and placed on a flat surface. A small amount of X-rays are passed through the baby’s body to measure the amount of bone, fat, and lean tissue (muscle) in his or her body. This test takes about 3 minutes. The toddler DXA causes no discomfort. The total radiation dose an infant receives during a DXA scan is thought to be less than 0.001% of the yearly safe limit recommended by the Food and Drug Administration.
In our gestational diabetes study we examine the liver of our infants with Magnetic Resonance Imaging (MRI). This procedure is optional and is not required for participation in the study. If you consent for the MRI scan we have you feed, swaddle, and rock your baby to sleep. Then we place infant earplugs in your baby’s ear so that his/her sleep is not disturbed by the MRI machine. Your baby will then be placed into the scanner, where we will perform the experimental measurements of liver fat, visceral fat, and subcutaneous fat. MRI does not involve radiation, is painless, and there are no dangers to your infant. We estimate that the scan will take approximately 35 minutes total. Along with the study research team, a pediatrician co-investigator (Dr. David Brumbaugh) will be present for the entire scan.