In most mammals, birth is straightforward: the fetus enters the birth canal head-first through a canal wide enough that rotation is minimal. In humans, the same process requires a precise choreography of rotations — and still frequently doesn’t go according to plan. Breech presentation occurs in about 3–4% of term pregnancies. From an evolutionary perspective, this is a predictable consequence of one of the most constrained births in the animal kingdom.
The obstetric dilemma
Bipedalism narrowed the human pelvis. Brain expansion enlarged the human skull. These two evolutionary pressures pulled in opposite directions, and the birth canal became the contested terrain between them. The result is a pelvic outlet that is barely large enough — and in some women, not large enough — to allow cephalic (head-first) presentation to navigate without difficulty.
Breech presentation may, in some cases, represent the fetus’s own adaptive response to this constraint. If the head cannot engage smoothly in the pelvis, remaining breech is arguably a rational, if ultimately problematic, alternative. Modern caesarean rates for breech — which have climbed from near zero to near 100% in many countries over 50 years — tell their own story about how poorly calibrated human birth has become.
The sacropelvic environment
Breech presentation is associated with uterine shape and placental position — but also with sacropelvic mechanics. Restrictions in sacral mobility and asymmetries in the uterine ligaments can create uneven uterine tone, influencing fetal position in the third trimester. This is the basis of osteopathic sacropelvic work in late pregnancy aimed at optimising the mechanical environment for fetal positioning.
What this means at OQ
At OQ, we work with women throughout pregnancy, including in the third trimester. Sacropelvic assessment and gentle pelvic balancing work aims to create conditions in which optimal fetal positioning becomes more likely — not to force a specific position. This is always done in communication with the patient’s obstetric team.
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