Design: Multicentre open-label randomised superiority trial
Population: 715 women under 60 with heavy menstrual bleeding eligible for ablation
Primary outcome: Hysterectomy within 2 years
Effect: 4% vs 10%; RR 0.43 (95% CI 0.24–0.77)

MIRA2 randomised 715 women under 60 with heavy menstrual bleeding at 34 Dutch hospitals to endometrial ablation alone or ablation followed immediately by a 52 mg levonorgestrel intrauterine system. Median age was 45.

At two years, 4% of women in the combined group had needed a hysterectomy against 10% with ablation alone (RR 0.43), about one avoided hysterectomy for every 17 women treated. Serious adverse events were similar, about 8% in each group.

Ablation fails in a predictable minority because residual endometrium regrows. Adding a progestogen coil at the same sitting is cheap, uses a familiar device and needs no extra procedure.

The trial was open-label, so decisions about hysterectomy could have been influenced by knowing allocation, and follow-up is two years. Bleeding patterns, satisfaction and later coil removal will matter for counselling.

Discuss inserting a levonorgestrel coil at the time of ablation with women choosing endometrial ablation.
Explain that combined treatment reduced the chance of later hysterectomy from about 1 in 10 to 1 in 25 at two years.
Counsel on hormonal side effects and the need for coil replacement.
Consider the coil alone first where it has not been tried, as standard practice.

Why it matters

A device already in every gynaecology clinic may spare a meaningful share of women a second, bigger operation.

The statistics, in plain English

A relative risk of 0.43 means less than half the risk, and the risk difference of 6 percentage points translates to one hysterectomy avoided per about 17 women. The confidence interval (0.24 to 0.77) is clear of 1. Serious adverse events had a relative risk of 0.98, meaning no detectable difference.