Safety is a priority. You must have insurance, in any case, but have a good awareness of some conditions that maternity and newborn clients may have, which will direct the session. You must know when to 'call it' if you have a mother or baby who seems to be unwell, or you aren't sure what it is but have a gut feeling.
While we are not there to diagnose, though sometimes I have a vague idea of what something could potentially be, it is really important to have an awareness and to recommend that they seek professional / clinical advice at their earliest opportunity. Health comes first, always before photographs.