The space is narrow and it can take time. So how does the baby experience delivery? Very little is known about this, but what we do know is it's a tough journey.
A narrow birth canal
Despite all this, we know that babies are subjected to considerable strain during labour and the delivery itself. This is mainly due to the simple physical fact that its body has to adjust in order to squeeze through the birth canal. This is clear when you look at a baby’s head after it has been born – the back of the head, which normally presents first, is swollen. As the bones in the baby’s skull have not yet merged, this does not endanger the baby. It is, however, important that pressure does not increase too suddenly. The labour therefore needs to take its time – both for the sake of the baby and of the mother-to-be.
Labour prepares the baby for breathing
The passage through the birth canal also compresses the chest so that the fluid in the lungs is forced out, making it much easier for babies to take their first breath.
The blood flow to the placenta decreases during the labour process, which means that for a short while the baby is getting less oxygen and nutrition. The baby was built to withstand this strain but if labour is prolonged, the baby’s resources may be depleted and its heart rhythm may change. This is why babies are so well-monitored throughout labour.