Thank you for your query.
I do understand your concern.
Prominant sutures in some parts are common in premature children due to overlapping of sutures.
If it was of conecrn your doctor will notify you in due time.The soft spot is called fontanalle and is normal.
The birth defect
is unlikely from drug abuse
Do talk with the neonatologist about the drug abuse of the mother and to check for probable defects arising from them.
Consult your doctor if the problem persists.
If you have any further queries you are free to consult me.
Hope this answers your query.
Wishing a speedy recovery.
Have a nice day.