NO it doesn't.
based on my experience when my wife is pregnant, the most important is making sure your wife not getting too tired, have enough nutrient, and not in stress.
For me, all those like signal radiation is just some marketing scheme for people selling healthy product lol.(or those 5g pandemic believer)
Fact if your phone have signal, mean there are signal there, and wifi signal is everywhere (yes wifi and phone signal is different but they are basicly only diffrent Hz), so if those signal is hurtful, our only option is live in the jungle?? ooo wait in most jungle we can use satelite phone to get the signal..