Hello,
When I was infant teacher in daycare one of the things I learned was the importance of letting a child know that I was going to get up and do something. I was left alone with three infants (which is ratio) so if I had three babies who were new and needed me to hold at the same time and I had no helper then I had to let them know what I was up to so that they could feel more secure. I think we forget that babies are people with feelings and require the same courtesy from us. So for example, if all three babies were on my lap and I needed to start warming bottles or getting their coats ready for outside "I would say "I am getting up to warm bottles." They may all start crying, but giving them reassuring glances and saying I will be back to bring your bottle okay." I found that in time they were so used to me telling them what I was doing that they eventually settled. All day if I was on my own with three babies this is how I did things to help the infants feel reassured. Think of it this way: You are sitting with a good friend over coffee chatting away when all of a sudden with no explanation she stands up to leave with no explanation. How would you feel? Many times we almost have to place ourselves in their shoes to get a feeling of how to help an infant through these stressful times. All the best.