Analgesia requirements and predictors of analgesia use for women undergoing medical abortion up to 22 weeks of gestation

Objective To assess analgesia use and the predictors for requiring analgesia in women undergoing medical abortion at all gestations up to 22 weeks.

Design Retrospective observational study.

Setting Aberdeen Royal Infirmary, Scotland.

Population Consecutive women undergoing medical abortion under the terms of the 1967 Abortion Act.

Methods Analgesia requirements and characteristics of women undergoing abortion were analysed using logistic regression.

Main outcome measures The effect of age, gestation, reproductive history, route and dose of misoprostol administration on analgesia requirements.

Results Of the total 4343 women included in this review, 3139 women (72%) required analgesia. Of these, 3054 women (97%) used oral analgesia, 75 women (2.4%) used opiates while 10 women (0.3%) had diclofenac sodium given rectally. There was no significant difference in analgesia use whether women used the vaginal or sublingual route of misoprostol administration. Logistic regression showed a significant positive association with gestation at termination (odds ratio [OR] 1.09, 95% confidence interval [CI] 1.05-1.12), number of misoprostol doses used (OR 1.31, 95% CI 1.13-1.51) and induction to abortion interval (OR 1.08, 95% CI 1.03-1.12) and a negative association with the age of women undergoing abortion (OR 0.98, 95% CI 0.97-0.99) and previous live birth (OR 0.43, 95% CI 0.33-0.56).

Conclusions Analgesia requirement was significantly higher in women of younger age, higher gestation, longer induction to abortion interval and with increased number of misoprostol doses used while women with previous live birth were significantly less likely to use analgesia.