Hi and welcome to Healthcare Magic... Thanks for your question.
I'm sorry to hear that your sister hasn't been doing well and can understand how stressful and concerning this can be to you.
Now, I am assuming that the diagnosis you have mentioned (postnatal
depression) is correct and has been confirmed by the doctors treating her and my opinion here is based on that.
Post-natal depression affects about 10-15% of mothers and can be sometimes be quite disabling and difficult for the mother as well as the baby.
As a general rule most facilities would try to keep the baby with the mother as it is very important for 'bonding'... Unless there is a risk of harm to the baby. Psychiatrists should keep assessing this risk periodically and their management decisions should also be based on this.
As regards the treatment is concerned, there are various options available such as medication, psychological therapies and in very specific cases electro-convulsive therapy (ECT). Since you have mentioned that the depression is severe, I presume that she would already be on anti-depressant medication. Now, it is to be remembered that anti-depressants can take some time (2-3 weeks) to bring about its effects, and that may be a reason why her doctors want to wait for some time.
However, if at any time, they feel that there is any risk to either the baby or the mother, they should take appropriate measures to ensure safety of the baby and the mother. In certain severe cases, especially if the patient is very suicidal or if there is severe self-neglect or certain symptoms called 'catatonic' symptoms, then electro-convulsive therapy would be the recommended treatment.
I hope that your doctors are assessing her periodically and are keeping in mind the risk to the baby and the mother. I suggest that you could keep in touch with you sister's husband regarding her improvements and the treatment plans, as any major decision regarding treatment will be taken only after discussing with and getting the consent of her husband. If there arises a situation to keep the baby away from her, then again, where and with whom will also be discussed with her husband.
Hope this helps and hope your sister gets well soon...
Regards,
Dr. Jonas Sundarakumar
Consultant Psychiatrist