Popular Science has a great (and occasionally horrifying) slideshow of gadgets it once suggested were essential for enlightened, tech-minded parents. A lot of the inventions merely look way sketchy. For instance, the infant-sized "sleeping porch" that is actually a screened box bolted into an apartment window frame is probably mounted well enough that it's not going to kill anybody. It's just that, from the vantage point of a 100 years later, it seems a little disturbing to stick your baby into something that looks like a large AC window unit.
Other suggestions, though, are legitimately concerning. Above, you can see an image of a nurse "branding" a newborn by essentially sunburning its parent's initials onto its flesh with a UV lamp. In 1938, somebody thought this would be a good way to ensure that nobody left the hospital with the wrong baby.