The Scottish Conservatives called for society and families to unite to change attitudes towards sex following the news.
Health spokeswoman Nanette Milne MSP said: "This news will have shocked many people and the impact on the lives of the two children, the mum-to-be and her baby must be the first concern.
"I hope that this incident will draw attention to failings that have allowed such a young girl to go on a night out, get drunk, get pregnant, yet seemingly be ignorant about the risks and consequences."
A Catholic Church spokesman criticised "an increasingly promiscuous culture".
ADDENDUM: Libby Brooks:
If it's a decision made freely, and properly supported, there is nothing essentially wrong with having a baby before you're twenty. But, instead of condemning the root causes, like social exclusion, poor sex education or lack of opportunities, it is the young women themselves who have been continually vilified by the press and politicians as slags or scroungers - despite there being no evidence that teenagers get pregnant to procure better housing or benefits.