If you're wondering what this pregnant belly business is about, you have to know that mpreg (or male impregnation) is another popular trope of knotting. And while that deserves a whole post on its own (it exists both inside and outside the world of knotting and fan fiction) its connection to knotting can't be denied.
The term levocurvature of the lumbar spine means leftward deviation of the lumbar spine. The curvature is greatest (apex) at l4. Dextrocurvature or dextroscoliosis would refer to a rightward deviation of the spine. Would you like to video or text chat with me?
What is Levoscoliosis? Is a clinical condition where a part of the spine is abnormally curved to the left. It commonly affects the lumbar part of the spine (also called Lumbar Levoscoliosis) though it can also have an effect on the thoracic spine and as a result can have an impact on the heart and lungs i.e. the structures within the thoracic cage.