1.1 Search strategy.
We selected relevant studies by searching PubMed, Embase, Web of
Science, Cochrane Library, SinoMed, CNKI, WanFang Data and VIP. We also
searched Chinese Clinical Trial Registry
(https://www.chictr.org.cn/)
and Clinical Trials.gov
(https://clinicaltrials.gov/).
All the databases were searched from inceptions to July, 2021. The
search strategy consisted of 3 components: participant (parturition,
parturitions, birth, childbirth, deliveries), intervention (auricular
acupuncture, auricular acupressure) and study type (randomized clinical
trial).
Study Selection
Two independent investigators (Z.W. and H. Z.) reviewed study titles and
abstracts. Studies that satisfied the inclusion criteria were retrieved
for full-text assessment.
1.2.1 Inclusion criteria. Relevant studies were included if the
following criteria were met. (1) Types of studies: randomized controlled
trials (RCTs) with or without blinding. (2) Participants: women intended
vaginal delivery with a fetus at full term. (3) Types of intervention:
with obstetric care routine, treatment groups that received auricular
therapy (including auricular acupressure and auricular acupuncture)
during the whole labour process or only the first stage of labour were
included; we compared ear point therapy with obstetric care routine
during the whole labour process or the first stage of labour. (4) Types
of outcome measures: we included studies that measured pain level,
visual analogue scale (VAS) score, duration of any stage of labour,
maternal satisfaction, neonatal Apgar score, number of spontaneous
delivery cases, number of caesarean section cases and postpartum blood
loss.
1.2.2 Exclusion criteria. (1) Duplicate publications. (2) Studies
with incomplete information which was still not available after attempts
to contact the authors. (3) Studies combined other acupuncture therapies
(manual/laser acupuncture, electroacupuncture, body acupressure,
moxibustion and transcutaneous electrical nerve stimulation).