The methodological challenges of attempting to compare the safety of home and hospital birth in terms of the risk of perinatal death.

This paper identifies a number of methodological difficulties associated with the comparison of home and hospital birth in terms of the risk of perinatal death, and suggests ways in which these problems can be overcome. A review of recent studies suggests that most available data sources are unable to overcome all of these challenges, which is one of the reasons why the debate about whether perinatal death is more likely if a home birth is planned or if a hospital birth is planned has not been satisfactorily resolved. We argue that the debate will be settled only if perinatal mortality data from a sufficiently large number of maternity care providers over a sufficiently long period of time can be pooled and made available for analysis. The pooling of data will bring about its own difficulties due to variations over time and between providers and geographical areas, which would need to be taken into account when analysing pooled data. However, given the impracticality of a randomised controlled trial and the rarity of home birth in most of the Western world, we argue that more effort should be made to pool data for perinatal mortality and other rare pregnancy outcomes, and share them between health providers and researchers. Thus, high-quality analyses could be conducted, allowing all women to make an informed choice about place of birth. However, pooling data from countries or states with very different maternity care systems should be avoided.