The dictionary definition of the word perinatal states

Perinatal:

Pertaining to the period immediately before and after birth. The perinatal period is defined in diverse ways. Depending on the definition, it starts at the 20th to 28th week of gestation and ends 1 to 4 weeks after birth. The word "perinatal" is a hybrid of the Greek "peri-" meaning "around or about" and "natal" from the Latin "natus" meaning "born."

With this in mind, Perinatal Illness can include:

Antenatal depression or anxiety

Postnatal depression or anxiety

Birth trauma (postnatal Post traumatic stress)

PNI is not confined just to mums - partners can suffer too.

Perinatal illness strikes indiscriminantly and can affect up to 10% of women (according to recent studies by the Royal College of Midwives,2007)

Although certain factors can contribute to a parent developing PNI, more often than not it 'just happens'.

The good news is that it is temporary and a sufferer will recover once they have the correct treatment.

Current NICE guidelines suggest the use of antidepressant medication for the treatment of postnatal depression/anxiety and in some cases of antenatal depression/anxiety too (this is when the GP and or specialist agree that it is important to do so for the wellbeing of mum and the unborn child)

Talking therapies are also recommended by NICE - especially in the case of Postnatal PTSD where early debriefing is paramount. In the case of depression/anxiety though it is often considered to be advantageous to wait until antidepressants are well established prior to therapy due to the large range of emotions that can be raised during sessions - a mum who already feels vulnerable can be made to feel even worse by these emotions and therefore the therapy may be much less effective.