• Cost-effectiveness;
  • economic evaluation;
  • first trimester;
  • miscarriage

Objectives  To compare the cost-effectiveness of alternative management methods of first-trimester miscarriage.

Design  Economic evaluation conducted alongside a large randomised controlled trial (the MIST trial).

Setting  Early pregnancy assessment units of seven participating hospitals in southern England.

Sample  A total of 1200 women with a confirmed pregnancy of less than 13 weeks of gestation with a diagnosis of incomplete miscarriage or missed miscarriage.

Methods  Random allocation to expectant management, medical management or surgical management. Collection of health service and broader resource use data, unit costs for each resource item and clinical outcomes.

Main outcome measures  Costs (£, 2001–02 prices) to the health service, social services, women, carers and wider society during the first 8 weeks postrandomisation. Cost-effectiveness estimates, expressed in terms of incremental cost per gynaecological infection prevented; cost-effectiveness acceptability curves presented at alternative willingness-to-pay thresholds for preventing gynaecological infection.

Results  There was no significant difference in the incidence of gynaecological infection between groups. The net societal cost per woman was estimated at £1086.20 in the expectant group, £1410.40 in the medical group and £1585.30 in the surgical group. Expectant management had a 97.8% probability of being the most cost-effective management method at a willingness-to-pay threshold of £10,000 for preventing one gynaecological infection, while medical management had a 2.2% probability of being the most cost-effective management method. Expectant management retained the highest probability of being the most cost-effective management method at all willingness-to-pay thresholds of less than £70,000 for preventing one gynaecological infection.

Conclusions  Expectant and medical management of first-trimester miscarriage possess significant economic advantages over traditional surgical management.