Pain control in first-trimester surgical abortion: a systematic review of randomized controlled trials

First-trimester abortions especially cervical dilation and suction aspiration are associated with pain despite various methods of pain control.

Following the guidelines for a Cochrane review, we systematically searched for and reviewed randomized controlled trials comparing methods of pain control in first-trimester surgical abortion at less than 14 weeks gestational age using electric or manual suction aspiration. Outcomes included intra- and postoperative pain, side effects, recovery measures and satisfaction.

We included 40 trials with 5131 participants. Because of heterogeneity, we divided studies into seven groups: Local anesthesia: Data were insufficient to show a clear benefit of a paracervical block (PCB) compared to no PCB. Reported mean pain scores (10-point scale) during dilation and aspiration were improved with carbonated lidocaine [weighted mean difference (WMD), -0.80; 95% confidence interval (CI), -0.89 to -0.71; WMD, -0.96; 95% CI, -1.67 to -0.25], deep injection (WMD, -1.64; 95% CI, -3.21 to -0.08; WMD, 1.00; 95% CI, 1.09 to 0.91), and with adding a 4% intrauterine lidocaine infusion (WMD, -2.0; 95% CI, -3.29 to -0.71; WMD, -2.8; 95% CI, -3.95 to -1.65). PCB with premedication: Ibuprofen and naproxen resulted in small reduction of intra- and postoperative pain. Conscious sedation: The addition of conscious intravenous sedation using diazepam and fentanyl to PCB decreased procedural pain. General anesthesia: Conscious sedation increased intraoperative but decreased postoperative pain compared to general anesthesia (GA) [Peto odds ratio (Peto OR) 14.77 (95%, CI 4.91-44.38) and Peto OR 7.47 (95% CI, 2.2-25.36) for dilation and aspiration, respectively, and WMD -1.00 (95% CI, -1.77 to -0.23) postoperatively). Inhalation anesthetics are associated with increased blood loss (p<0.001). GA with premedication: The cyclooxygenase (COX)-2 inhibitor etoricoxib; the nonselective COX inhibitors lornoxicam, diclofenac and ketorolac IM; and the opioid nalbuphine improved postoperative pain. Nonpharmacological intervention: Listening to music decreased procedural pain. No major complication was observed.

Conscious sedation, GA and some nonpharmacological interventions decreased procedural and postoperative pain, while being safe and satisfactory to patients. Data on the widely used PCB are inadequate to support its use, and it needs to be further studied to determine any benefit.