The foetus is fully formed at the end of the sixth month. The
womb then enters the incubation period. All the baby's bodily
organs and systems develop fully during that time, and the womb
accelerates this growth by providing nourishment for the foetus.
This period continues until the baby emerges from the mother's
womb. The birth canal is normally very narrow and it is
difficult for the foetus to pass through it. During birth,
however, a number of physiological changes take place in the
mother's body. These changes allow the foetus to move easily
through the birth canal. Some of these changes include: the
expansion of the joints in the pelvic bones in order to widen
the birth canal, the relaxation of the muscles to further widen
the canal and the lubrication of the canal with amniotic
fluid.92 These pre-birth changes are described in one scientific
source in these terms: As birth approaches, the amniotic fluid
embarks on those activities that will be necessary to facilitate
that birth. This fluid comprises sa