To evaluate efficacy, side effects and complications of NO donors for cervical ripening before first-trimester surgical abortion.
SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register, MEDLINE, EMBASE and Popline. We also searched reference lists of retrieved papers. We contacted experts in the field for information on both published and unpublished trials.
SELECTION CRITERIA: Randomised controlled trials comparing NO donors alone or in combination with other methods for cervical ripening in first-trimester surgical abortion.
DATA COLLECTION AND ANALYSIS: Two reviewers independently selected and extracted the data onto a data extraction form. We processed the data using Review Manager (RevMan5) software.
MAIN RESULTS: We included eight studies involving 718 participants. There were no serious complications (
infection requiring
antibiotic treatment,
blood transfusion, complications requiring unintended operation, cervical injury,
uterine perforation, death or serious morbidity) in the trials included.NO donors were ineffective in cervical ripening comparing with placebo or no treatment. The cumulative force required to dilate the cervix to 8 mm (mean difference -4.29, 95% CI -9.92, 1.35), baseline cervical dilatation before the procedure (mean difference 0.21, 95% CI -0.12, 0.53),
headache (RR 1.73, 95% CI 0.86, 3.46),
abdominal pain (RR 0.87, 95% CI 0.51, 1.50) or patient satisfaction (RR 0.95, 95% CI 0.84, 1.07) were not different. More
nausea and
vomiting occurred in the women who received a NO donor (RR 2.62, 95% CI 1.07, 6.75).NO donors were inferior to
prostaglandins for cervical ripening. The cumulative force required to dilate the cervix to 8-9 mm was higher (mean difference 13.12, 95% CI 9.72, 16.52) and baseline cervical dilatation was less (mean difference -0.73, 95% CI -1.01, -0. 45) in the NO donor group. Side effects including
headache (RR 5.13, 95% CI 3.29, 8.00), palpitation (RR 3.43, 95% CI 1.64, 7.15),
dizziness (RR 3.29, 95% CI 1.46, 7.41) and intraoperative blood loss (mean difference 33.59 ml, 95% CI 24.50, 42.67) were also higher. However,
abdominal pain (RR 0.33, 95% CI 0.25, 0.44) and
vaginal bleeding (RR 0.14, 95% CI 0.07, 0.27) was less in the NO donor group. Patient satisfaction was not different.One trial compared a NO donor with a NO donor plus
prostaglandin. The cumulative force required to dilate the cervix to 8 mm was higher (mean difference 14.50, 95% CI 0.50, 28.50) in the NO donor group. There was no difference in
headache (RR 0.88, 95% CI 0.38, 2.00),
abdominal pain (RR 0.14, 95% CI 0.02, 1.07) or intraoperative blood loss (mean difference -50, 95% CI -164.19, 64.19).
AUTHORS' CONCLUSIONS: