We all get the hiccups from time to time. Nevertheless, it is mainly babies who get the hiccups after they have drunk something. Parents try everything they can to stop the hiccups. If you enter the search term “hiccup babies” into Google, you’ll get almost 700,000 suggestions on what you can do about it. According to the latest insights, the best thing to do is to simply let the hiccups take their course. It would appear that this phenomenon has an important influence on the development of a newborn’s brain.
Hiccups are especially common in premature babies
A study at University College London (UCL) found that hiccups caused a surge of brain activity which help the baby learn to regulate its breathing. The scientists’ theory is supported by the fact that hiccups start in babies after just 9 weeks in the womb. This makes it one of the earliest patterns of activity in the unborn child. On top of that, premature babies are especially sensitive to hiccups, with a daily duration of about 15 minutes.
“The reasons behind our hiccups are not entirely clear. But it could be down to a a developmental reason as to why fetuses and newborns hiccup so often,” says Kimberley Whitehead, the main author of the study and a researcher at the Research Department of Neuroscience, Physiology and Pharmacology (NPP) at UCL.
During their study, the scientists recorded the brain activity of 13 newborns who had hiccups. Brain activity was recorded using EEG (electroencephalogram) electrodes on their scalps. Motion sensors on the babies’ bodies recorded when they swallowed. The premature babies were all born between the 30th and 42nd week of pregnancy. This may be a reflection of what usually happens in the last trimester of pregnancy.
Babies learn to control their breathing
The researchers found that the contractions of the diaphragm muscle caused by the hiccup caused a pronounced reaction in the cerebral cortex – as in two powerful brainwaves followed by a third. Since the third brain current is similar to that of a sound, the researchers believe that the brain of a newborn may be able to combine the “hiccup sound” of the hiccup with contraction of a muscle in the diaphragm. Researchers believe that this “postnatal processing of multisensory inputs” is important for the development of brain connections.
“The activity induced by a hiccup can help the baby’s brain to learn how to control its respiratory muscles. As a result, breathing can ultimately be controlled at random by moving the diaphragm up and down, says Dr. Lorenzo Fabrizi, the principal author of the study. “At birth, the circuits that process physical sensations are not yet fully developed. So building these kinds of networks is a crucial stage for the development of newborn babies.
The question remains as to why we still get the hiccups later on in life. For example, in stressful situations or while eating, or when drinking carbonated drinks. Scientists can only make assumptions about this. “Our results have raised the question as to whether hiccups in adults (which are actually just a nuisance) can indeed be caused by a spastic reflex left over from childhood when it used to have an important function.”
The research project was conducted at the Research Department of Neuroscience, Physiology and Pharmacology (NPP) at UCL and at the Elizabeth Garrett Anderson Maternity Department of University College London Hospitals NHS Foundation Trust (UCLH). It had been funded by the Medical Research Council with support from the National Institute for Health Research UCLH Biomedical Research Centre. The results have been published in the medical journal Science Direct.