There’s not a right answer for this besides YES you need to communicate with the birth moms before the dinner. For some people that could be one exchange to confirm they’re coming and provide the address. For others, there could be more communication back and forth beforehand. As the host, making them feel welcome before they even arrive is the goal. And communication is a way to do that either by phone, email or text. Communicating pre-dinner builds some accountability too. By providing information and answering their questions, you’re setting expectations and hopefully easing some fears they have about even showing up.