3.1 Main findings
Meta-analysis showed that auricular acupressure was more effective for
latent analgesia in the first stage of labour, but not in the active
stage, which may be related to different severity of pain in the active
and latent stages of labour. However, the incidence of grade III pain
throughout labour was reduced in the auricular acupressure group,
suggesting that auricular acupressure is effective in relieving
breakthrough pain in labour. Since breakthrough pain after receiving
pain relief can increase patient’s
dissatisfaction[27],the maternal satisfaction
shown in the meta-analysis was improved.
For the duration of labour, the first stage of labour was shorter in the
auricular acupressure group, whereas the second and third stages of
labour were not significantly different, which may be associated with
the longer duration of the first stage of labour.
The safety of auricular acupressure is investigated through Apgar score,
delivery mode and postpartum hemorrhage. These outcomes did not show any
significant difference between auricular acupressure groups and the
controls.
3.2 Limitations
First, only published Chinese and English articles were retrieved, which
may lead to publication bias due to incomplete literature collection.
Second, most included studies did not provide methodological details on
randomization, allocation concealment and blinding, which reduced the
reliability of the findings. Besides, although only one study used
auricular acupuncture, the stimulation of auricular acupressure and
auricular acupuncture is different, and the intensity of stimulation may
vary between studies due to the degree or frequency of pressure. The
significant heterogeneity of some outcomes may be attributable to this.
In addition, although labour pain is different between nulliparous and
multiparous women, the size of the fetus can also affect labour pain,
some studies failed to specify these factors.
3.3 Implication for clinical trial design
As a subjective feeling, labour pain is highly complex, further
well-designed trials with high methodological quality should be
conducted, and careful trained clinicians and standardized intervention
protocols are needed to minimize the subjective effect. Besides, to
explore the differential analgesic effects among nulliparous and
multiparous women and the effect of fetus size on labour analgesia,
further studies as well as the manipulate methods (e.g. acupressure and
acupuncture) are needed.