Menarche in adolescents from Vojvodina (the Republic of Serbia) in the period 2001-2019.

Menarcheal age is the starting point of reproductive life and could be a marker of health and socioeconomic status of a population.The aim of this study was to assess the temporal pattern in variability of menarcheal age from 2001 to 2019 and the relationship with biological factors and educational level of parents. : A cross-sectional anthropometric survey was conducted in three intervals: 2001-2004, 2011-2014 and in 2019. In total, 5201 adolescent girls from Vojvodina (North Serbia) aged 11-18 were surveyed, 3272 (62.91%) of them with menarche. Data on the age at menarche was gathered applying method and the age at menarche was calculated by probit analysis. The surveyed traits included height, weight and Body mass index (BMI). : Mean menarcheal age declined from 12.60 ± 1.11 years to 12.33 ± 1.20 years during the period from 2001 to 2019. Within three investigated periods variance decreased after the first decade from 1.23 year to 1.09 year, and then increased to 1.44 year. On average, postmenarcheal girls were 4.36 cm taller, 8.03 kg heavier, and their BMI was 1.96 kg/m higher than in premenarcheal girls of the same calendar age. An inverse effect of BMI and mother's education on the menarcheal age was detected, but the interaction between the variables was not statistically significant. These results indicate continuing decrease in menarcheal age in girls from Vojvodina. Menarche is closely associated with BMI and it appears that this factor effects the age at menarche irrespective of the parents' education.