In the third trimester of pregnancy, all women will notice the onset of daily hiccups from their babies in utero. Why is this? Is it normal?
It is perfectly normal and reassuring of a normally developing nervous system. The nervous system begins to mature in a fetus around 26 weeks gestation and , as a result, a series of reflexes begin to become apparent in the growing baby by 32 weeks. The term hiccup (or hiccough) originates from the Latin meaning “to gasp”. Hiccups are actually a reflex caused by involuntary contractions of the diaphragm and rib muscles that result in a sudden inspiration and closure of the glottis (AKA “voice box”). These reflexes, hiccups included, persist through the third trimester and generally disappear when the baby is around 3 months of age.
When a fetus has a hiccup, the muscles involved with breathing contract and it is suspected that this exercises the breathing muscles before the baby is born. As the nervous system is maturing, a fetus will have several episodes of hiccups every day.
So, next time your feel those sudden intermittent little spasms in your uterus in the third trimester, be reassured that your baby is maturing normally and exercising the little breathing muscles in preparation for taking his or her first breath in the first moments of life.