Spooked cat- delayed stress?

Hello everyone. I was hoping for some help with one of my 9 month cats please.
We have had brothers Mittens and Mão since they were 10 weeks old and have been great ever since we brought them home from the shelter. Very playful and loving, perfect kitties really.

2 weeks ago we brought out newborn home ,to which I had prepared as best I could with a feliway plug in, additional posts and had played sounds of babies crying. Both reacted great, no usual signs of distress and carried on as normal (to my eyes anyway). We try and give them as much play and cuddle time as we can even if it isn't as much as it was prior to baby being here. We have had a few visitors over the 2 weeks and Mao would sit on the top of the stairs out of the way and be quite tense (Mittens couldn't care less and likes the attention). One set of visitors included boisterous children which resulted in Mao cowering under the bath for some time. He did come round within the hour and for the next few days was back to being himself.

However myself, partner and baby went out for 4 hours yesterday and came back to Mão hiding again in the bathroom, seeming to be scared of something in the house. No one had been in and nothing had changed. All night he was on edge and this morning still a little wary, looking at the hall way as if something is there (which in itself is spooky!)
Could this be a delayed reaction to everything that has happened in the past 2 weeks? He was walking with a low back to ground, dilated pupils and took some time to settle and play with his toys.
He is in our bedroom now asleep on his shelf and has purred but I'm still concerned for him. Any more visitors are banned until I can be sure it won't make him even more on edge.

I hate thinking he is distressed and so far he has thankfully ate, pooped and weed with no stress related marking.

Any advice would be great

>^..^

He is stressed by numerous things and when they all add up, it seems to be affecting him.  You have the new baby, visitors and a change in your behavior too.  He picks up on all of it.  Being a new Mom, your behavior is different and the daily schedule of the home is now different.  It may take him awhile. 

How many feliway diffusers do you have?  They only cover a very small area so you made need 3 or more in your home.  You should have one in every room where the cats hang out.  You also can try Composure liquid max.  It's a non sedating calming supplement.  You can add it to wet food 2x a day.  It can make a big difference.  You can find it on Amazon or EntirelyPets.com

Pet stores may carry the treat variety, but many cats do not like the treats.  They are large and it takes quite a few to get enough into the cats.  The liquid is much easier, but must be ordered online.

I would suggest that when visitors come, put the cat in a room and put on some calming music or white noise or even a tv to help drown out the sounds.  You may want to do this for awhile.  Make sure in the room you place him, he has things that are comforting to him. 

He will adjust, but it can take a long time.  Thank you for being proactive and helping to be sure he adjusts.  Kudos to you!!!  Also Congratulation on the birth of your child.  What an exciting time of your life.

Hi thanks for your response its great. I just have the 1 diffuser in the kitchen above their feeding station. I use the spray in the living room on their contact points. I still have an old style Feliway diffuser in the cupboard so will try source an old style refil for it and get that plugged in too. Why Ceva changed the product, I don't know. Im sure I read they were going back to the old design again.

Im getting some food calming supplement tomorrow whilst picking up their litter. Not the brand you mentioned, but M&C serene- um drops.

Mão has been great today and interacted with my partners parents when thet came round. He is used to them as they cat-sitted when we were on holiday earlier this year so I'm glad he hasnt been totally put off by guests. However if anyone else comes that he is unfamiliar with I will put him in our bedroom as he likes to sleep on the shelves above our bed and can hide under the bed if he wants to be totally out of the way. Also play some music like you suggested.

He has more or less returned to his usual behaviour, but I know he himself will still be experiencing the change in home life and will continue to try my best to keep him calm. I hate seeing him stressed.

One more question- if he gets really freaked out again and hides away, is it best to leave him alone and come round in his own time or make a fuss ie with treats and petting him. I would assume the former, but its hard not to go cuddle him as to reassure him (which i know is a human response)

Great news that he is doing better!!!  If he does it again, I would let him be.  I would only coax him out if he has been under there for hours and hours and won't come out to eat.  Allow him the space to hide and come out on his own.

One of my cats is afraid of anyone who comes into my home.  He is also petrified of the vacuum cleaner.  He will hide for hours and hours.  Yet that is where he feels safe.  He always comes out at meal time if the coast is clear.  If we have guests and it's meal time, I will often take the food into the room he is hiding. 

Just keep giving him extra attention while he is out and about.  If he goes to hide, just allow him that freedom.

Thanks for updating.