The mid-century Baby Boom came after WWII, and probably had very little to do with technology. The upswing started some time in late 1944 to mid 1945 as combat was winding down in Europe and a lot of young men were returning home. Otherwise fertility has been declining steadily since 1800 in western countries.
No, this is exactly the opposite of true: you need to do more reading about the baby boom. It happened across many countries, including ones which had little involvement in WWII, and in almost all cases it began in the 1930s, even with the Great Depression underway. It got supercharged by the end of the war because that's when the economic doldrums finally ended, but upward trend in fertility predated even the beginning of the war, never mind the end.
https://www.statista.com/statistics/1033027/fertility-rate-u...
The above shows the boom started in the 40s in the U.S. after 140 years of gradual decline.
The technological explanation wouldn’t really account for any increase in places where 1930s and 40s technology hadn’t been deployed. I’d need a little more than hand waving to evaluate or engage with your argument.
See https://www.derekthompson.org/p/what-caused-the-baby-boom-wh...
I don’t agree with Thompson, his start date is the place where fertility hit a local minimum, not the year where the rate really took off which was 1946. A lot of the technological innovations actually predated his arguable start date by 5-10 years and several happened well into the boom.
I think his explanation fits the thesis of his recent book, which I actually like, but it seem a bit off here.