Strengths and limitations
Immediate insertion of the IUD after medical abortion at 17-20 GW has not to our knowledge been studied. Most women in our study represented a group which is particularly vulnerable to infringements on their sexual and reproductive health and rights, which makes this study of particular relevance.
The study estimated sample size did not accurately predict how many women would not receive an IUD in the immediate group or how many would fail to follow-through for delayed insertion. Despite this, findings were statistically significant and loss-to-follow-up lower than predicted. Our sensitivity analysis used a conservative scenario that minimized outcome differences between groups in order to adjust for the uncertainty of missing and self-reported data and did not change the direction or significance of our findings.
The study was embedded in clinical services which currently have relatively little experience with IUD insertions which may make results less generalizable to other contexts. To mitigate this both hospital staff and CHC staff received structured mentoring sessions in IUD insertion after medical abortion prior to the study start. It is however unlikely that varying experience had a measurable impact on expulsion as expulsion rates were low with interval placement and replacement of the IUD.
Compared to a non-study situation, the study environment and other interventions may have influenced women´s behaviours or opinions but they should not affect relative results. The impact of study procedures on results as well as the feasibility of the intervention is being explored in a separate process evaluation.