The age of menarche has been gradually declining since the end of the 20th century. Few studies have been carried out about dysmenorrhea in Europe and they mainly included girls over the age of 15 years.

We conducted an observational study among sixth-grade schoolgirls (usually 11-12 years) during the 2020 academic year in 72 randomly selected public schools in a French region (approval number #20.94).

Among 1712 girls interviewed, 257 (23 %) had reached menarche. Overall, 83 % of these teenagers had dysmenorrhea. Symptoms were reported to occur since the first periods in 59 % of the girls. School absenteeism was positively correlated with severe abdominal pain (p = 0.001). Median age at menarche was 11 years (10.7–11.5). Periods lasted less than 3 days, 3–8 days, and more than 8 days in, respectively, 18 %, 70 %, and 7 % of the girls. Symptoms were significantly more frequent and more severe in the urban group than the rural group (p = 0.005). Symptoms were abdominal pain (70 %), fatigue (48 %), difficulty in concentrating (26 %), headache (25 %), digestive disorders (16 %), and breast discomfort (11 %). Of the girls with dysmenorrhea, 61 % took painkillers; 10 % were uncomfortable despite taking painkillers. Sport exemption was more frequent in the urban group (p = 0.003) and among girls with severe abdominal pain (p = 0.001).

The duration of the menstrual cycle was similar between the various socioeconomic groups, but symptoms and ways of coping were significantly different. Dysmenorrhea is definitely an issue that has to be raised with teenagers as soon as menarche occurs or even before that. Easy access to skilled health practitioners should be widespread.