From the Guidelines

Exposure to laser treatments at an aesthetic clinic can harm a fetus.

The evidence provided does not directly address the risks of laser treatments at an aesthetic clinic to a fetus, but it discusses the complications associated with laser surgery in the context of twin-twin transfusion syndrome (TTTS) treatment.
However, in the context of real-life clinical medicine, it is reasonable to err on the side of caution and assume that exposure to laser treatments could potentially harm a fetus, especially considering the sensitive nature of fetal development.
The studies cited (1, 1, 1, 1, 1) focus on the treatment of TTTS using laser photocoagulation and discuss various complications, including preterm premature rupture of membranes, preterm delivery, and fetal demise, but these are in the context of a medical procedure, not aesthetic use.

Laser safety is crucial in any setting, and the risk of exposure to laser treatments during pregnancy should be minimized to prevent any potential harm to the fetus.
While the provided evidence does not directly address aesthetic laser treatments, basic human physiology suggests that unnecessary exposure to any form of radiation or energy during pregnancy should be avoided when possible.
In real-life clinical practice, precautionary measures should be taken to protect the fetus from potential harm, including avoiding unnecessary exposure to laser treatments during pregnancy.

From the Research

The use of laser therapy during pregnancy has been evaluated in several studies, with some indicating that it can be safe for certain conditions 2, 3.
A systematic review of elective laser therapy during pregnancy found that laser therapy can be used as a safe treatment for urolithiasis, skin diseases, twin to twin transfusion syndrome, and varicose veins of the lower extremities 2.
Another systematic review of the maternal and fetal effects of laser therapy during pregnancy reported no cases of maternal or fetal morbidity or mortality, premature labor, or identifiable fetal stress in 380 pregnant women who underwent laser treatment 3.

However, other studies have reported potential risks associated with laser treatment during pregnancy, including fetal loss and aplasia cutis congenita 4.
A study on interstitial laser therapy for fetal reduction in monochorionic multiple pregnancy found a procedure-related fetal loss rate of 10% per pregnancy and 11% per fetus 4.
Complications of aesthetic laser surgery have also been reported, highlighting the need for careful consideration and caution when using laser therapy during pregnancy 5.

A study on the effect of laser acupuncture on fetal well-being during induction of labor found that laser acupuncture had no significant effect on fetal movement, but may induce labor if the cervical length is less than 1 cm and dilation (0) 6.
The study reported no significant difference in enrollment delivery time between the laser acupuncture and sham groups, and no adverse effects on the fetus were observed 6.