To assess the efficacy and safety of nonablative 1 565-nm Er:Glass fractional laser in the treatment of striae gravidarum.

The left and right sides of the abdomens of 30 subjects with striae gravidarum were divided into 2 groups by simple randomization: treatment group treated with nonablative 1 565-nm Er:Glass fractional laser every 4 weeks for 3 sessions, and control group receiving no treatment. These subjects were followed up at the baseline, 4th, 8th and 12th week. At the same time, photos were taken, the skin flexibility was evaluated, and the width of striae was measured. Four weeks after the final treatment, clinical improvement was evaluated by 2 doctors, who were blind to the therapeutic protocol, according to clinical photos and three-dimensional (3D) images, and satisfaction scores were also evaluated. Skin biopsies were taken from the left and right sides of the abdomens of 3 subjects, and subjected to histopathological examination. Four months after the final treatment, all the subjects were telephoned for evaluation of adverse reactions and recurrence.

A total of 27 subjects completed the whole trial. Four weeks after the final treatment, 25 (92.6%) of the 27 subjects were considered to achieve an improvement by doctors. However, 21 (77.8%) of the 27 subjects considered themselves to achieve an improvement. After 3 sessions of treatment, the treatment group showed a significant decrease in the largest width of striae from 4.852 mm to 3.296 mm (P < 0.001) and a significant increase in skin flexibility from 0.803 to 0.878 ( P < 0.001) . Histopathologically, the control group showed obviously atrophic epidermis and decreased collagen and elastin in the dermis, while the treatment group showed thickened epidermis and dermis, extended rete ridges, and increased collagen and elastic fibers which arranged more regularly. Immediate adverse reactions during the treatment included erythema and edema, and other adverse reactions included mild crust, itching and post-inflammatory hyperpigmentation (PIH) . PIH was improved at 4 months after the final treatment compared with that at 4 weeks after the final treatment.

The nonablative 1 565-nm Er:Glass fractional laser can markedly improve the width and appearance of striae gravidarum, and increase skin flexibility in the treatment region.

Laser therapy; Treatment outcome; Safety; Striae gravidarum; 1565 nm Er:Glass fractional laser