Carbon monoxide (CO) poisoning during pregnancy can be fatal for the fetus, or cause bone malformations or encephalopathy, depending on the stage of pregnancy at which the poisoning occurs. Fewer cases of death and encephalopathy have been reported since the adoption of maternal hyperbaric oxygen (HBO) therapy in this setting, but these children's long-term psychomotor development and growth remains to be documented. A prospective single-center cohort study spanning 25 years (1983 - 2008) included all pregnant women living in the Nord-Pas-de-Calais region of France who received HBO for CO poisoning and who gave birth to a living child. A descriptive analysis of the women and children was performed first. A control group of children was created by matching with anonymous files from local authorities. The results of the children's compulsory health & development assessments were used to compare the two groups. 406 women were included in the study, of whom 6 were expecting twins. The psychomotor development of 412 children was monitored, up to the day 8 assessments in 388 cases, the year 2 assessments in 276 cases, and the year 6 assessments in 232 cases. Sixty children have not yet reached the age of 6 years. No significant differences in psychomotor or height/weight criteria (p > 0.05 for both) were found between the exposed and unexposed children. No malformations were reported. These findings support the use of HBO therapy for all expectant mothers exposed to CO poisoning. No specific follow-up of the children is necessary if their neonatal status is normal.