The worry is common. The trials do not bear it out.
A 2021 review of twelve randomized trials, all starting at twelve weeks or later, found that massage in uncomplicated pregnancies reduced stress, anxiety, low mood and back and leg pain. Only two trials reported side effects, and they were minor and passing; the complications that occurred were judged most likely unrelated to massage. The precautions the authors name are the ones this room follows: on your side, nothing on the belly, no deep work through the legs, no concentrated essential oils.
- Mueller SM, Grunwald M (2021). Effects, Side Effects and Contraindications of Relaxation Massage during Pregnancy: A Systematic Review of Randomized Controlled Trials. Journal of Clinical Medicine. PubMed