The prevalence and influencing factors of anaemia among pre-pregnant women in mainland China: a large population-based, cross-sectional study

Anaemia is a global public health problem affecting women worldwide, and reproductive-age women are at increased risk. We conducted a population-based cross-sectional study analysing the prevalence of overall anaemia and anaemia according to severity in Chinese pre-pregnant women to update current knowledge on anaemia epidemiology. Based on the National Free Preconception Check-up Projects supported by the Chinese government, 5 679 782 women participating in this project in 2017 were included in the present study. The cyanmethemoglobin method was applied to assess Hb concentrations. Univariate and multivariate logistic regressions were applied for associated factors. The prevalence of anaemia among Chinese pre-pregnant women was 21 center dot 64 % (mild: 14 center dot 10 %, moderate: 7 center dot 17 % and severe : 0 center dot 37 %). The prevalence of overall and severe anaemia was the highest in Tibet and the lowest in Beijing among thirty-one provinces. Women's age, region, ethnic origin, educational level, occupation and pregnancy history were all correlated with anaemia. Women with B blood type (adjusted OR (aOR) = 0 center dot 89), higher BMI (overweight: aOR = 0 center dot 84; obesity: aOR = 0 center dot 70) and alcohol consumption (aOR = 0 center dot 69) were less likely to have anaemia, while those with rhesus negative blood type (aOR = 1 center dot 10), history of anaemia (aOR = 2 center dot 60), older age at menarche (aOR = 1 center dot 19), heavy menstrual blood loss (aOR = 1 center dot 39), longer menstrual period (aOR = 1 center dot 09) and shorter menstrual cycle (aOR = 1 center dot 08) were more likely to suffer from anaemia. Meat or egg eaters were not significantly associated with severe anaemia. Anaemia is of moderate public health significance among Chinese pre-pregnant women. Interventions should be considered to prevent anaemia to the greatest extent possible to avoid potential harm in this population.