Much attention has been focused on the consequences of breech presentation and on strategies to minimise risk for both the fetus and the mother. Studies, including the landmark term breech trial, have had a positive effect on clinical practice and set a standard in developed countries of caesarean delivery for persisting breech presentation.1 2 3 Less attention, however, has been focused on why some fetuses deliver in breech position. In the accompanying paper, Nordtveit and colleagues investigate whether the risk of breech delivery can be passed on through generations via both men and women.4

The prevalence of breech presentation decreases through gestation as fetuses mature, and most fetuses move into cephalic position before delivery. The prevalence of breech presentation is 25% at 28 weeks’ gestation and 3-4% at term.5 Risk factors include maternal characteristics (primiparity, contracted pelvis, high maternal age, and uterine abnormality); characteristics of the …