Recently released statistics on the infant mortality rate in the Western hemisphere yielded an odd conclusions — Cuba’s infant mortality rate, 16 6.0 per 1,000, is now lower than the U.S. infant mortality rate, at 7.2 per 1,000. Given Cuba’s poverty level, its 6.0 rate is very impressive, but is it accurate to say that Cuba now has an infant mortality rate lower than the United States? No.
The problem is that international statistics on infant mortality are helpful in revealing large differences, but when it comes to small differences such as that between Cuba and the United States, often other factors are really behind the numbers.
The primary reason Cuba has a lower infant mortality rate than the United States is that the United States is a world leader in an odd category — the percentage of infants who die on their birthday. In any given year in the United States anywhere from 30-40 percent of infants die before they are even a day old.
Why? Because the United States also easily has the most intensive system of
emergency intervention to keep low birth weight and premature infants alive
in the world. The United States is, for example, one of only a handful countries that keeps detailed statistics on early fetal mortality — the survival rate of infants who are born as early as the 20th week of gestation.
How does this skew the statistics? Because in the United States if an infant is born weighing only 400 grams and not breathing, a doctor will likely spend lot of time and money trying to revive that infant. If the infant does not survive — and the mortality rate for such infants is in excess of 50 percent — that sequence of events will be recorded as a live birth and then a death.
In many countries, however, (including many European countries) such severe medical intervention would not be attempted and, moreover, regardless of whether or not it was, this would be recorded as a fetal death rather than a live birth. That unfortunate infant would never show up in infant mortality statistics.
This is clearly what is happening in Cuba. In the United States about 1.3 percent of all live births are very low birth weight — less than 1,500 grams. In Cuba, on the other hand, only about 0.4 percent of all births are less than 1,500 grams. This is despite the fact that the United States and Cuba have very similar low birth rates (births where the infant weighs less than 2500g). The United States actually has a much better low birth rate than Cuba if you control for multiple births — i.e. the growing number of multiple births in the United States due to technological interventions has resulted in a marked increase in the number of births under 2,500 g.
It is odd if both Cuba and the U.S. have similar birth weight distributions that the U.S. has more than 3 times the number of births under 1,500g, unless there is a marked discrepancy in the way that very low birth weight births are recorded. Cuba probably does much the same thing that many other countries do and does not register births under 1000g. In fact, this is precisely what the World Health Organization itself recommends that for official record keeping purposes, only live births of greater than 1,000g should be included.
The result is that the statistics make it appear as if Cuba’s infant mortality rate is significantly better than the United States’, but in fact what is really being measured in this difference is that the United States takes far more serious (and expensive) interventions among extremely low birth weight and extremely premature infants than Cuba (or much of the rest of the world for that matter) does.
This does not diminish in any way Cuba’s progress on infant mortality, which is one of the few long term improvements that the Cuban state has made, but infant mortality statistics that are that close to one another are often extremely difficult to compare cross-culturally.