One hundred and five articles were included in the review, comprising 42 RCTs, six CCTs, 54 case series/reports, and three surveys. The quality of data from RCTs and CCTs was mostly poor (findings were fully reported in the review).
Fifty five studies did not mention adverse events, 22 studies reported there were no adverse events, and one study reported that fewer adverse events occurred in the acupuncture group, but with no further details. Twenty five studies (27 articles) reported details on 429 adverse events. The total incidence of adverse events in the acupuncture group was 1.9% (429 events in 22,283 sessions). The risk of mild/moderate adverse events was 1.5%
Mild adverse events (322 events): Mild adverse events (302) involved maternal complications, mostly needle or unspecified pain or local bleeding, but also including events such as rash or sleep disturbance and excessive fatigue. Mild foetal adverse events (20) included small for date and multiple twists of the umbilical cord or shoulder.
Moderate adverse events (6 events): Moderate adverse events included fainting and transient fall in blood pressure.
Severe adverse events (99 events): Severe maternal complications (86) mainly included events such as hypertension and/or pre-eclampsia, but also included preterm delivery (<37 weeks), tachycardia and atrial sinus arrhythmia. Severe adverse events were considered unlikely to have been caused by acupuncture treatment. Foetal complications included congenital defects and admission to neonatal intensive care units due to preterm delivery. There were two infant deaths considered unlikely to be caused by acupuncture and no maternal deaths.
Sensitivity analysis reported that the total incidence of adverse events in the acupuncture groups was 4.8%.
Further results were reported in the review.