Excessive crying in babies is an issue for up to one in five families, causing pain for the baby and stress for the parents.
Acupuncture is associated with relieving pain, restoring gut function, and inducing calm, and the researchers wanted to see if it might also resolve excessive crying in colicky babies.
They therefore compared two types of acupuncture with standard care alone in 147 babies whose colic was confirmed at statutory routine check-ups in four child health centres in Sweden.
All the babies were aged between 2 and 8 weeks of age and were otherwise healthy. And they had all been on a cow's milk exclusion diet for at least 5 days in a bid to curb excess crying/fussing.
Each child was randomly allocated to one of three groups (A-C), which required additional twice weekly visits to the child health centre for two weeks. These included a half hour appointment with a nurse to discuss symptoms while the statutory appointments included routine childcare advice plus weighing and measuring.
Group A received standard minimal acupuncture at one acupuncture point (L14) for 2-5 seconds without stimulation; group B were given tailored acupuncture at a maximum of five acupuncture points for up to 30 seconds with mild stimulation; and group C received no acupuncture.
Parents were asked to keep a detailed diary of how often and how long their child cried.
The procedure was carried out by 10 clinicians, nine of whom were fully trained acupuncturists, who had been in practice for an average of 20 years. They all also attended an education day on acupuncture for colic.
In all, 144 babies completed the two week trial. The amount of time spent crying excessively fell in all three groups, which is not unexpected as colic tends to clear up by itself eventually, say the researchers.
But the magnitude of this reduction was greater in those given either type of acupuncture than it was in those given standard care alone.
And a significantly higher proportion of babies in the acupuncture groups no longer fulfilled the criteria for colic compared with those in the standard care group after two weeks of treatment.
During the second week of the trial, 16 babies in group A still had infantile colic, compared with 21 in group B and 31 in group C.
Parents continued to record bouts of crying for six days after their final clinic visit, and these differences in outcome between the three groups were still evident then.
The babies seemed to tolerate acupuncture fairly well. Out of 388 treatments given, the baby didn't cry at all on 200 occasions, and cried for less than a minute on 157 occasions. Only 31 treatments triggered a crying jag of more than 1 minute. A single drop of blood was evident in 15 treatments.
"Fussing and crying are normal communications for a baby, therefore a reduction to normal levels (rather than silence) is the goal of treatment," say the researchers, who emphasise that parents should record how long their baby cries to see if it is excessive and then try eliminating cow's milk from their feeds before seeking further help.
But they conclude: "For those infants that continue to cry for more than 3 hours/day, acupuncture may be an effective treatment option."