The hazards of childbirth are an inevitable consequence of those two unique features of our species: standing upright, which narrows the outlet of the pelvis, and the (relatively) large size of the infant’s head. As a result the force of the uterine contractions necessary to impel the baby down the birth canal are ten times more powerful, and painful, than those of our primate cousins. Those labour pains may in addition be compounded by a constant excruciating back pain caused by stretching of the ligaments around the womb.
Those travails might be ameliorated in some women were greater use made of the astonishingly simple method of preventing those excruciating back pains during labour â€“ injecting a small amount of sterile water into the skin on either side of the lumbar spine. This works by stimulating the local nerve fibres that then ‘block off’ the painful sensations induced by the stretching of the ligaments around the womb. The injections abolish the back pains for up to three hours with a measurable effect in improving the experience of childbirth.