Why the world's most powerful country has the second-worst infant- mortality rate in the developed world, just pipping Malta and Slovakia, is a puzzle. The usual answer to why so many American babies die before they are one year old is inadequate health care funding. But a paediatrician at the University of Massachusetts Medical School, Darshak Sanghavi, has a different idea. He believes that it is "the unintended side effect of increased spending on medical care".

Writing in the on-line magazine Slate, Dr Sanghavi points out that one-third or even one-half of infant mortality is due to complications of prematurity. And a large contributor to prematurity is fertility treatment. About half of IVF pregnancies in the US result in multiple births, with a high risk of premature delivery. In effect, better and more IVF has worsened the rate of prematurity.

How about changing the dismal statistics with better care, then? This is the conventional solution and neonatal intensive care units are multiplying across the US. Although this sounds impressive, studies suggest that this is harming the health of babies. If the facilities are available, babies without serious illness may be admitted and submitted to risky procedures. Outcomes also tend to be worse in smaller, less experienced units. "Less money and less patient choice sound heretical -- but, in this case, eminently sensible," concludes Dr Sanghavi.