Fetal hiccups occur when an unborn baby's diaphragm contracts, typically due to breathing in amniotic fluid. They are considered normal, and often feel rhythmic, like a heartbeat in the womb that can often even be felt from the outside. Some unborn babies tend to hiccup more than others, even several times each day, and the same pattern may continue once they are born. Baby hiccups usually begin in the second or third trimester, though they sometimes can also start in the first trimester. Though they may appear to bother a baby once he is born, fetal hiccups do not tend to cause discomfort in the unborn baby, and may even soothe him to sleep while in the womb.
There is usually a reason for unborn baby hiccups, just as there is when children and adults get them. Fetuses practice breathing while in the womb, and since they are surrounded by amniotic fluid, they often breathe it in and out. When it enters the lungs and then exits, the diaphragm contracts, resulting in fetal hiccups. Since a developed nervous system is necessary in order to hiccup, unborn baby hiccups are not usually noticed until the second or third trimester, at which point it is an indication of proper growth.
Another reason for fetal hiccups is to practice the reflex of sucking and swallowing, which allows most babies to latch on to their mother's breast to eat directly after birth. Fetuses that do not practice this habit may not be able to effectively prevent milk from entering their lungs and choking them when they eat. Additionally, there is reason to believe these hiccups can help regulate the heart rate in the third trimester. Therefore, fetal hiccuping is not only normal, but is usually a good thing.
Despite the fact that hiccups in a fetusshould be considered a good sign of growth, sometimes doctors become worried about this type of fetal movement. This is likely because it can sometimes mean that the unborn baby is not getting sufficient air due to umbilical cord compression. This is when the cord wraps around the baby's neck so that he cannot breathe, causing his heart rate to become rapid. The main symptom of this issue is the sudden increase in hiccups, followed by a lot of fetal movement in general once the air supply is limited. An ultrasound should be sought immediately if these symptoms occur, though the cord tends to wrap around the neck over time rather than suddenly.