Abstract: This updated review includes nine new studies, in total 26 studies with 28 comparisons and involving 2790 participants. No study of local paracervical versus general anaesthesia met our criteria. Ten studies compared local anaesthetic versus placebo. Paracervical local anaesthetic (PLA) reduced pain on cervical dilatation with a standardized mean difference (SMD) of 0.37 (95% CI 0.17 to 0.58) and a relative risk (RR) of severe pain of 0.16 (95% CI 0.06 to 0.74). PLA also reduced abdominal pain during, but not after, uterine intervention (SMD 0.74, 95% CI 0.28 to 1.19); there was no evidence of any effect on postoperative back or shoulder pain. Comparisons against no treatment did not demonstrate any effect of PLA. Five studies compared paracervical block with uterosacral block, intracervical block, or intrauterine topical anaesthesia. Two of these studies showed no significant difference in pain during the procedure. Compared to intrauterine instillation, PLA slightly reduced severe pain (from 8.3 to 7.6 on a 10-point scale), which may be negligible. Six studies compared PLA with sedation. There were no statistically significant differences in pain during or after the procedure, postoperative analgesia requirement, adverse effects, patient satisfaction, and the operator's perception of analgesia. We performed risk of bias assessment using six domains and found that more than half of the included studies had low risk of bias. We found that no technique provided reliable pain control in the 26 included studies. Some studies reported that women experienced severe pain (mean scores of 7 to 9 out of 10) during uterine intervention, irrespective of the analgesic technique used. We concluded that the available evidence fails to show whether paracervical block is inferior, equivalent, or superior to alternative analgesic techniques in terms of efficacy and safety for women undergoing cervical dilatation and uterine interventions. We suggest that woman are likely to consider the rates and severity of pain during uterine interventions when performed awake to be unacceptable in the absence of neuraxial blockade, which are unaltered by paracervical block.

Plain-language summary: Cervical dilatation and uterine interventions (such as hysteroscopy, endometrial biopsies, fractional curettage, and suction terminations) can be performed without any analgesia or anaesthesia; with regional anaesthetic injections as with paracervical block; using oral or intravenous analgesics and sedatives; or under general anaesthesia. Many gynaecologists use paracervical block for uterine intervention but it is unclear how effective and safe this method is. We included nine new studies in this updated review with a total of 26 studies involving 2790 women undergoing uterine interventions. The women were randomly allocated to paracervical block or an alternative. We found that, statistically, women had significantly less pain during cervical dilatation and uterine intervention with paracervical block than with placebo injection (saline or water) but clinically this difference may be unimportant. Paracervical block had no effect in five uncontrolled studies. There was no evidence that paracervical block reduced pain compared to alternative regional anaesthetic methods or systemic analgesics and sedatives. There was little information on important side effects. After updating, this review found that no local anaesthetic technique prevented pain as well as one would expect from general anaesthesia.