This can be different for everyone. It is recommended to make a plan with your caseworker before giving birth as to what you want contact to look like. Your caseworker can help you communicate your desires of openness with the prospective adoptive family and a mutually agreed upon plan can form. This is with an understanding that it can change and adapt over time, depending on circumstances.
Flexibility and honesty can create space for a healthy open adoption. Talk to your caseworker for help developing these agreements and to better understand what can and cannot be enforced with open agreements in your state.