ad. 34. How to plan ultrasound examination in the second trimester if I am a high BMI woman?
Among people with extensive amount of subcutaneous tissue, ultrasound penetration is weakened, and a fetus is located in a greater distance from the abdominal surface and the transducer. In such cases, a sonologist assesses fetal structures distantly, like through a fog, which is a great impediment. Most patients, and even a number of physicians in charge do not realize the problem.
A scan of each patient should be performed with the same precision. Therefore, it is good to prepare a scan of a high BMI patient well. We propose to carry out the examination of the second trimester in two stages: the first stage at around 16 – 17 weeks, when a vaginal access is still possible and the second stage at around 20 weeks. When it comes to costs, we treat this kind of situation as one examination. That kind of approach simplifies the matter and gives the patient a guarantee that a baby was examined accurately. In case of any doubts it is worth asking the sonologist during assessment in the first trimester if a transabdominal ultrasound scan will not be hindered in the second trimester.