To the Editor: In 2000, the United Nations Millennium Summit produced an agenda for reducing global poverty. It listed eight Millennium Development Goals (MDGs) and was signed by 189 countries. Improving maternal health (with the aim of reducing the maternal mortality ratio by three-quarters between 1990 and 2015) is the fifth and perhaps the core health-related MDG if we consider the centrality of mothers in social development and health.1,2 Globally, the number of maternal deaths remains high at 529 000 per annum.2 Ensuring maternal survival demands functional health care systems with skilled health care workers. However, migration of health care workers (mostly to wealthier English-speaking countries) is a major threat to achieving the MDGs.3-5 Here, I estimate the associations between maternal health and physician migration and human resources for health.

I used recently updated physician migration3 and global health workforce data4 to look at correlations between physician migration and two core maternal health indicators — the maternal mortality ratio, and the percentage of births attended by skilled personnel.1,2 I also explored the associations between these maternal health indicators and human health care resources. Migration was measured as the number of physician émigrés working in Australia, the United Kingdom, Canada, and the United States during 1999–2002, per 1000 population of their source countries.5 Physician migration density values for all four countries combined, and for each country individually, were determined (Box). Human health care resources included current densities of health care workers remaining in the source countries (Box).

I calculated the Pearson’s correlation coefficients between these variables and the two core maternal MDG indicators.

The Box shows that countries with better maternal health are likely to have higher physician migration and more human resources for health care. For example, higher migration to Australia is seen from countries with lower maternal mortality (r = − 0.29; P = 0.011) and more births attended by skilled staff (r = 0.25; P = 0.037).

I acknowledge that, like most health system and global health analyses, these correlations are based on an ecological (cross-country) design which does not lend itself to causal inference. These findings are therefore descriptive and require further exploration. Furthermore, the two maternal health indicators used here (which are the core maternal health MDG indicators used by the United Nations) could be viewed as indicators of health system and population health progress. Although physicians and other health care workers play major roles in maternal survival, especially in pregnancy, they cannot be seen as the only requirements for better maternal health. Physicians’ roles can also be substituted by other health care workers in many situations in resource-poor settings.

However, less-poor source countries often have higher capacities than poor nations to turn out skilled workers who subsequently migrate. Contrary to conventional wisdom, Australia, the UK, Canada, and the US draw substantially more migrant physicians from countries with higher health care worker capacities. Many countries may be losing physicians just when they should be reaping the benefits of their improving fortune. Given the patchy progress towards achieving the MDGs,1 health care worker shortages may impede many countries’ progress in improving health standards if migration rates exceed workforce replacement in the face of changing but increasingly complex health care needs.1,2,4

Physician migration must be taken seriously if the global target of reducing maternal mortality by three-quarters between 1990 and 2015 is to be realised and sustained. Australia and other Western countries must partner with source countries to develop strong political commitment and scaled-up investments in human resources for health.