Fear....of losing something precious.
Mind you , hormones throw all rational thinking out of the window.

Fear. Makes you do all sorts of desperate things.

Nothing compared to the amount of people who find "Jesus" after age 60. Seems people become "born avain" when they realize how close they are to deaths door. Normally their younger days were filled to the brim with indiscretions that hurt a lot of their family and friends.

That did not happen to me.

Yes! Preach!!! I know exactly what you mean!! The pothead rebel kid growing up is now the loudest bible beater on Facebook. This lady has it out to annoy the crap out of me at all stages of life, apparently!!

I have heard some friends say it’s important to them that their kids grow up with moral instruction. There’s that assumption that religion is required for morality!! I prefer my moral instruction with more history and reverence for mystery.

TBH, I can empathize. The community of concern and support one finds in a church is harder to find the secular world, in my experience. I just joined a UU church for that reason. No creed required!!

Postnatal psychosis? I dunno, I've never been pregnant, but it's pretty well-established that pregnancy hormones can do a number on the brain sometimes.

Probably fear. Need for support they are not getting anywhere else. If they get it there they likely take that as a sign they are where they need to be.

When I first became a mom I didn't have much support but church was the last thing on my mind. Like anything else I pretty much faced and tackled it. Information digging and making sure daddy took in some baby time so I could catch my breath and take a break.

People only find religion when they need something to believe in during a difficult time. God isn't found during good times in people's lives.

They suddenly feel responsible, all the big questions they of a non deep thinking mind, of non phiolosophic bent, never consider; come leaping to the forefront,and they have no answers for those.
Religion offers ready answers with no need for deep thinking.
A ready to eat microwave meal
Instead of a homemade Lasagna

Alot of people think that a church will help with teaching morals to children.However where you raise children is important.I feel for people in areas where peer pressure is so hard on children.Country raised,and less materials spoils are far better,than high powered jobs,jj and demands.

Where are you getting that information? I know I didn’t turn to mythology when my son was born, nor did I turn to it when he died.

Its like everybody's saying... its fear.

Fear and the "just in case" type thing. I once read that Walter Brennan wanted to check into religion a little further because "he wasn't getting any younger." That explains a lot for me.
Pregnant women might often think they have to get serious now because they are bringing another child into the world and they have to raise it right. OK. What does that have to do with gods or religion?

Fear. It is a 'just in case' move. I met a lady yesterday that will not do yoga because she is Christian, and does not want to be hear a Hindu thing. Same concept. Just scared

I have no idea but I have seen it, and I agree with your sentiment of "ugh"

I suppose some folks doubt their ability to create a moral structure they can justify to their kids, so they take the easy way out and let religion do it for them. Bad idea, if you ask me, and it's just a guess, but I bet it's true a lot of the times this happens.

First and foremost fear. Add in the changing family dynamics with a new baby (most especially the first new baby ) and many people decide that maybe there is something to be said for church. I fell into the same trap with new kids, a business that was under tremendous pressure to start being something other than a money pit, and the stress of marriage itself.

Perhaps looking for somewhere to dump sudden responsibility? (I'm not ready for this!)

I wonder if it has something weird to do with the idea of baptism. Also maybe even though they didn't go to church they really hadn't given up the idea of religion and there are certain rites they feel they must take part in. Makes me wonder though if once the child is born and grows up a bit if they stick to their church

Doesn't really happen in Britain. Engaged couples will often 'fake it' for a few months before the wedding and attend some services if they want to be married in church, but they just revert to normal once the knot is tied.

The fear element created by our society that drives people to do things that is cordoned by society

Some were probably were always prone to being persuaded but did not grow up in a particularly religious environment; others just had other priorities which change with their lifestyle, but were also prone all along. Bottom line is, as humans, we are all prone, some of us just had the audacity to look beyond the easy.

For the same reason ex smokers start smoking again, Stupidity !

Is this a varifiable trend or just a few people you know? I have not seen this with people I know but that also doesn’t prove you wrong. If we are atheists because we are critical thinkers then I would say without evidence we don’t know.