Abstrakt
We read with great interest the article of Østborg et al.1 The main conclusion was the positive relationship between a high body mass index (BMI) and a shorter duration of the active second stage of labour, which is based on robust evidence from population data. In the discussion the authors refer to our work as one of the possible explanations for their observation: their article states, 'One study found that adults with a history of obesity from adolescence tend to have a wider bony pelvis in adulthood [a reference to our work], which could facilitate the expulsion of the fetus'.
We would like to clarify this statement and point out some limitations of our study, which also limit the interpretation presented by Østborg et al. In our longitudinal study,2 we observed the relationship between obesity in adolescence and pelvic dimensions in early adulthood, i.e. a broader pelvis in individuals with a history of obesity from adolescence.
However, we were focused only on the bi-iliac and bi-cristal breadths, which are parameters of the greater pelvis (which are easy to measure using non-invasive anthropometry). It is essential to highlight that vaginal delivery is limited to the lesser (true) pelvis, which was outside the scope of our research.