Babies make all kinds of movements in utero, but one of the most distinctive is the sensation of hiccups. They can feel like baby is doing small, rhythmic hops, and they are normal and usually a fun sign that baby is preparing for life outside your body.
How do babies hiccup without breathing?
Babies do not breathe in the womb in the way we do because they are floating in warm and watery amniotic fluid. Your baby also does not need to breathe since the blood vessels in the placenta exchange blood that is rich with oxygen from your body with blood from which baby’s body has already removed the oxygen.
Even though babies do not breathe air in the uterus, they do start to practice breathing by inhaling amniotic fluid as early as week nine of pregnancy.  As baby inhales fluid, their diaphragm—the dome-shaped muscle below the lungs—contracts. If the diaphragm gets irritated and spasms, that is a hiccup. 
When will I feel my baby’s hiccups?
You will most likely feel baby’s hiccups after you have been feeling fetal movements for a while, so probably around the end of your second trimester.  Hiccups can feel like a small kick or jerky arm movement, but the way to truly identify them is by how rhythmic they are—much like adult hiccups. Some people say that fetal hiccups feel like popcorn popping in your belly and sometimes fetal hiccups are so consistent that you or your partner will be able to see them from the outside. Even though you probably will not feel baby hiccupping until a bit later in pregnancy, sometimes your care provider can detect them on an ultrasound in the first and second trimesters. [2,4] And though it is perfectly normal to feel baby hiccupping now and then, if you do not feel your baby hiccup, that is okay, too!
What do hiccups tell me about my baby?
Occasional hiccups are usually a signal that baby’s body is developing as it should. The ability to hiccup suggests that baby is practicing breathing, which is a positive indication that they will be able to breathe after they are born. Hiccups also are a sign that the nerves that control baby’s diaphragm are developing normally and communicating with baby’s brain. 
If you feel that your baby is having bouts of hiccups more than two to three times a day, it is worth mentioning to your care provider. A baby that hiccups often or for longer than about 15 minutes at a time in utero, especially in the third trimester, could have issues with their umbilical cord being compressed, which can make it tricky for baby to get the oxygen and nutrients they need. You are probably already tracking other fetal movements already, so pay attention to hiccups, too. If you notice anything that seems unusual for your baby, or if it seems like they are hiccupping a lot, check in with your doctor or midwife. 
Hiccups after birth
Just as babies hiccup on the inside, once they have joined you in the world they may also hiccup. Hiccups in newborns are common, normal, and often cute, but if you sense that your baby hiccups more than you would expect or if you feel concerns, you can always talk to your pediatrician. On very rare occasions, continuous newborn hiccupping could mean that your baby has reflux, but you would likely also notice other reflux symptoms, too.
If your newborn seems distressed by hiccups, here are some things you can try :
- Breastfeed: sometimes a bit of milk will help the diaphragm relax.
- Slow down feedings: if baby’s stomach fills with milk very quickly, it could expand and irritate the diaphragm. Try leaning back to breastfeed, especially if you have a fast letdown, which could help slow the release of milk from your breast. You can also burp your baby partway through a feed to slow down their milk intake.
- Gentle back rub or warm bath: a massage or bath might help baby’s muscles, including their diaphragm, relax.
- See your pediatrician: keep careful track of when and how often your baby has the hiccups, so you can talk it over with your baby’s doctor. Pay attention to other symptoms—spitting up, difficulty settling, tummy aches—so you can discuss those issues as well.
- Begin before Birth: Fetal Development
- Healthline, My Baby Hiccups in the Womb
- BabyCentre, Is it normal for my baby to get hiccups in the womb?
- The Bump, When Baby Has the Hiccups in the Womb
- WikiHow, How to Get Rid of Baby Hiccups