Objectives Underage pregnancy is associated with lower socioeconomic status and poorer birth outcome. Teenage pregnant workers may also have less experience in occupational safety. This study was aimed to investigate the possible association between underage pregnancy in employees and perception on occupational risk.

Methods A cross-sectional survey was conducted to collect data from pregnant factory workers visiting antenatal care clinic and post-partum ward in general and community hospitals at a north-east province of Thailand.

Results Pregnant employees who were underage pregnancy (less than 20 compared to 21–30 year of age) were found to be associated with higher perception on physical risk (OR, 3.01; 95% CI,1.44 to 6.31); chemical risk (OR,1.54; 95% CI,0.68 to 3.49); biological risk (OR,7.16; 95% CI,1.66 to 30.8) ergonomic risk (OR,2.79; 95% CI,1.27 to 6.09) and mental risk (OR, 1.48; 95% CI,0.62 to 3.51). The underage pregnancy was not associated with protective behaviour (OR,1.041; 95% CI, 0.52 to 2.10).

Conclusions underage pregnancy in employees have higher perception on physical, biological and ergonomic occupational risk but not for protective behaviour.