Joanna posted video of the ultrasound Wednesday after the couple announced they'd soon be welcoming their fifth kid. "Fixer Upper" fans speculated something was wrong with the images, because of excess fluid around the fetus. They've been commenting that the condition appears to mimic hydrops fetalis, a sometimes fatal condition.

Radiologist Nicole Saphier -- who has extensive experience in interpreting ultrasounds -- tells us there does appear to be skin edema (excess fluid in the skin). But Dr. Saphier is quick to add, although the ultrasound gives cause for concern, it's not conclusive. She says she'd need to see the whole ultrasound to determine if excess fluid is present in additional cavities such as the heart, lungs or abdomen.