The mid-century Baby Boom occurred after a surge in affordable home keeping technologies (vacuum cleaners, washing machines, refrigerators, etc). I think a rebound in fertility will have to come from technology. Specifically, robots to help with child care and new fertility treatments to allow women to have children later in their lives.
Tell me you don't have kids without telling me you don't have kids.
From an "efficiency" perspective, one can already eliminate 90% of the work of childcare by putting your kid in a sturdy playpen with a secure hard top and wearing noise canceling headphones. People don't really want to do this, for the most part.
The interactive learning is the entire point of childcare. Having machines raise your kids will make it so you end up with kids that were raised by machines. Is that what you want? It seems like this is basically already a thing, with the varying amounts of screen time that parents will allow kids.