As long as you can account for and adapt to optimize the well-being for each of their descendants, no problem. If, however, you are foisting an unknown number

As long as you can account for and adapt to optimize the well-being for each of their descendants, no problem. If, however, you are foisting an unknown number of new sentient beings into this world with no idea of who will take ownership of them or otherwise be accountable for their happiness, this behavior is seriously unethical and potentially negligent in a legal sense.