Data extraction
All of the potentially relevant literature were reviewed independently by two investigators and consensus was reached on all of the items. Any disagreements were resolved by discussion or with involvement of a third review author. CPR (presence of at least one gestational sac or fetal heartbeat, confirmed by transvaginal ultrasound) and LBR (a baby born alive after 24 weeks gestation) were the primary outcomes, and the secondary outcomes were ongoing pregnancy rate (OPR, pregnancy beyond 12 weeks of gestation, as confirmed by fetal heart activity on ultrasound),miscarriage rate (MR) and adverse events related to acupuncture. The following information was also needed: first author and published year, sample size, age of the study participants, acupuncture sessions or timing.