In which I answer your questions…
Q: Can laughing harm a fetus?
A: I think you need to be more clear. There are several ways to interpret that question.
1) Will laughing at a fetus harm it? For example, “Wow! You are an uuuuuuuuuuuugggglyyyyyy fetus!” *giggle*?
Yes. that will harm the fetus’s self esteem and when it is born, it will need to therapy immediately. Never laugh at the fetus.
2) I am pregnant, someone said something funny, and I laughed. Have I harmed my fetus?
I’m not a doctor or anything, but I believe that laughing during pregnancy is not only not harmful, but probably recommended.
3) I am a very funny person, and I told a joke to a pregnant woman, and although she didn’t laugh, her fetus did. Have I harmed the fetus?
Yes you have. Fetuses are discouraged from having a sense of humor due to the damage it can cause to their amygdala. (Also, I made that up.)