What's fascist is to forbid people from having children based on arbitrary criteria, which is just one obvious but wrong way to address an otherwise reasonable idea, that not everyone is fit for parenting. It doesn't mean the idea itself should be discarded. Here's another solution that doesn't trample on anyone's freedom: better informing people about the costs and benefits of parenthood. That would go a long way to prevent people from having children without the means to raise them.

You don't have to forbid anyone from having kids. Providing women with education and the pill is enough to drop in fertility below replacement level.