More than half of teenage girls experienced heavy bleeding and 40 per cent had an iron deficiency. The research, led from Lund University in Sweden, also shows that young teenage girls who experience heavy menstrual bleeding - and are therefore at greater risk of iron deficiency - can be identified using a simple questionnaire.
As many as half of the teenage girls in the study published in PLOS One experienced heavy menstrual bleeding, and four out of ten had an iron deficiency. The 2023 study was carried out in two Swedish upper-secondary schools; a total of 394 girls aged 15 and over took part. They responded to questions about menstruation and eating habits and provided blood samples for analysis of blood count (Hb) and iron stores (ferritin). Lund University has previously reported how the research team saw a particularly high risk of iron deficiency and anaemia among those eating a vegetarian or pescetarian diet. Now, researchers have gone further and investigated how the extent of menstruation affects iron deficiency and anaemia.
"We see a lot of young girls who are tired and distracted. Linking that to menstruation or diet is not obvious," says Moa Wolff, researcher and associate professor at Lund University, specialist physician in general medicine at Region Skåne and the researcher in charge.
Girls with heavy menstruation were three times more likely to have an iron deficiency, with an even higher risk for those who restricted the quantity of meat in their diet.
"Many of them only compare with their own previous experiences without knowing what counts as heavy menstrual bleeding. We also note that many are not aware of the over-the-counter medicines available that reduce the volume of blood," says Lisa Söderman, gynaecologist and postdoc researcher at Karolinska Institutet who collated the results for the article in question.
SAMANTA questionnaire could be a new tool for school health services
Part of the study evaluated a Spanish questionnaire which asks six questions. This is the first time it has been used in Sweden and the first time it has been tested on teenage girls anywhere, even though it is a validated screening instrument for adult women.
"Based on the answers to the questionnaire, it was possible to clearly identify which secondary school students were at risk of having low iron levels. It is easy to use and could be a valuable tool for school health services and youth clinics or other care healthcare settings where we meet these girls," says Moa Wolff.
Previous research shows that iron deficiency in young people may affect their energy levels, schoolwork and general wellbeing. Iron stores - Ferritin - form an important component in the formation of red blood cells and is needed for oxygen transport. Therefore, iron deficiency with low ferritin levels can eventually lead to a drop in haemoglobin, which can result in anaemia.
"In the next few years, some of these girls will get pregnant. When that happens, we would like them to have good stores of iron to enable as complication-free a pregnancy as possible, with a successful labour," says Lisa Söderman.
