Reporting rates of ectopic pregnancy: are we any closer to achieving consensus?

Calculating rates of ectopic pregnancy in a reliable and reproducible way can be challenging. To date, there is no consensus as to which denominators to use but the authors suggest using the total number of deliveries as a benchmark. In many developing countries where ectopic pregnancy is a major cause of maternal morbidity and mortality, standardisation of epidemiological data is arguably even more important. Using the number of deliveries is probably the most pragmatic and reliable way of quoting ectopic pregnancy rates in developing countries, as structures are usually already in place to record births/deliveries. This would ensure greater consistency and allow more meaningful comparisons to be made, both within individual units over time as well as globally. Using additional denominators is more labour intensive and lends itself to inaccuracy but may nevertheless be useful depending on the issues being addressed. Ultimately, the correct denominator(s) to use should be determined by the clinical question(s) of interest. The authors acknowledge that the statistical analysis used in this paper is based on one retrospective study alone and that further work is required in this area before definitive conclusions can be made.