Another possible reason that birth outside hospital leads to much lower rates of OASI is birth position.
While, in theory, birthing women and people in hospital are free to move into any position they wish, in practice the fact that the bed is central to the room means that most people just ‘hop up on the bed’ and, when in bed, we lie down.
Unless women and people are discouraged from doing this it is the most likely position they will labour and birth in. Many women also report being asked to lie down, or to get into a semi-recumbent position for birth, even if they’ve been active in other positions during the earlier part of their labour. In our recent survey on birthing positions, a overwhelming majority are asked and encouraged by their midwife to lie down.
Women can be often be asked to open their legs, and sometimes their legs are held open (which is illegal assault), yet when supported to follow their own instincts they often close their legs at the point that the baby is about to crown. Overriding a woman’s instincts, which are driven by sensations that only she can feel, should be over-ridden by the birth attendant at their peril. Or, rather, at the peril of the woman’s perineum.