When I was in the last few months of pregnancy with my daughter, my belly made it hard to get into a good sleep position. I was most comfortable laying on my right side, but without fail every time I snuggled into bed this way, my daughter would start kicking up a storm until I moved. I have no idea why she hated me laying that way so much, but it did make me a little paranoid that I was hurting her somehow. If you've ever wondered, "Can babies in the womb feel pain?", you might be surprised by how controversial a question that is.
For the sake of consistency, I'm going to use the term baby as opposed to fetus (but there's no judgment implied there) while looking at the different ways to answer this question. There's conflicting research about whether babies feel pain before they're born, and it's mixed up in the debate over abortion.
According to Medscape, by eight weeks of gestational age an unborn baby has pain receptors and will react to pain by 20 weeks. On the basis of claims like that, The New York Times reported that Utah passed a law that requires women undergoing an abortion at 20 weeks or later to take pain medication that is meant for the baby.
The American Congress of Obstetricians and Gynecologists (ACOG) made its position plain in 2013, however. It released a statement that said an unborn baby cannot experience pain until it's viable outside the womb, which happens around 24 weeks. Before that point, ACOG noted that a baby lacks the connections between the brain and nerves to process the sensation of pain. But some research has concluded that the time frame is even later than that. The Daily Mail noted that one study found that babies in the womb don't react to pain until about 35 weeks gestation, as demonstrated by their brain activity when having blood drawn from their heel.
Despite the conflicting accounts of whether babies feel pain in the womb, it does seem like there's consensus on one thing: there's not much need to worry if you bump your bump. According to Parenting, your baby has plenty of protection from amniotic fluid, so don't freak out if your belly knocks into a table or gets karate chopped by a toddler. There's a good chance they won't feel a thing.