Pregnancy Pillow Glossary
5 terms explained. Updated 2026.
Lumbar Support
Lumbar support in pregnancy pillows — what it means, how C-shape and U-shape pillows differ, and when lumbar support is the priority.
Round Ligament Pain
Round ligament pain — sharp pregnancy pain in the lower abdomen or groin caused by stretching ligaments. Explained with sleep positioning guidance.
Sleep On Side (SOS)
SOS (Sleep On Side) — NHS and ACOG guidance on left-side sleeping from 28 weeks, and how pregnancy pillows support the transition.
SPD (Symphysis Pubis Dysfunction)
SPD (symphysis pubis dysfunction) — pelvic joint pain in pregnancy caused by relaxin-softened ligaments. Explained with positioning guidance for sleep.
Trimester
Trimester explained — three stages of pregnancy, what happens in each, and how pregnancy pillow needs change across trimesters.