Ten to fifteen percent of pregnant women experience post-partum depression. These are not necessarily the same women.
This depression is hormonal, it is situational, it is to do with the character and disposition of the woman involved, it has to do with prior history and the quality of the relationships in her life. There are even links to breast-feeding (though old, this information has not been disproven, and is backed up anecdotally).
This depression has nothing to do with the baby or how the mum feels about her baby or her ability to be a mother once past the pregnancy and newborn hurdle.
This week is PND Awareness Week at KK Hospital. KK Women and Children's Hospital in Singapore has a unit specialized in peri-natal depression, and is working hard in making sure they find and help all the mothers in Singapore who need them. Of course, there are more places to turn to, such as the Mother and Child Centre in Tanglin Mall and on East Coast for the expat crowd.
The great majority, eighty to ninety percent, of mothers will never have to deal with any of this. But for those who do, follow the links. Get help. You may not believe you deserve it, but you owe it to your baby.