Maternal mortality in California

What’s going on in California? Why has the maternal mortality rate risen so sharply?

Nathanael Johnson, of California Watch, broke the story yesterday:

The mortality rate of California women who die from causes directly related to pregnancy has nearly tripled in the past decade, prompting doctors to worry about the dangers of obesity in expectant mothers and about medical complications of cesarean sections.

For the past seven months, the state Department of Public Health declined to release a report outlining the trend.

California Watch spoke with investigators who wrote the report and they confirmed the most significant spike in pregnancy-related deaths since the 1930s. Although the number of deaths is relatively small, it’s more dangerous to give birth in California than it is in Kuwait or Bosnia.

Unfortunately, it is impossible to figure out what is going on because the state of California is withholding information on the deaths. We don’t know the causes of death, the demographics of the mothers, or the level of care they received.

Although the state of California refuses to release the case by case accounting of the deaths, we can find some information. The California Maternal Mortality Care Collaborative (the same entity that is withholding the complete report) has some startling graphs on its website.

The graph above reveals several interesting findings. First, the maternal mortality rates have been rising in the US as a whole, but have been rising faster in California. Second, the large increase after 2002 reflects the change in the way that maternal mortality is reported. It had been suspected for some time that maternal mortality in the US was being substantially underestimated. New data collection forms confirmed this undercounting; hence part of the rise in maternal mortality reflects better data gathering. Third, rates of maternal mortality are so low that a few deaths can dramatically change the rates, hence the sawtooth nature of the graphs. Fourth, although the rates fluctuate from year to year, the overall trend is upwards.

The graph displaying racial differences in California maternal mortality is truly mind boggling.

Maternal mortality among Asian and Hispanic women is lower than or equal to the rates for white women. The maternal mortality rate for black women is astoundingly high, topping out at an extraordinary 54.9/100,000. That number is more than triple the rate for women of other races, and is consistent with overall US data from 2006 (white maternal mortality of 9.5/100,000 compared to black maternal mortality of 32.7/100,000). African Americans make up only 6% of the population of California, less than half the nationwide percentage, so the high rate of black maternal mortality cannot be blamed for the increase in California maternal mortality.

What is the reason for the high and rising rate of maternal mortality in California? Without patient level data, it is impossible to know. However, there are three possibilities: changing characteristics of pregnant women, changing level of care provided, and change in the type of care, specifically the rising C-section rate.

Does the increase in maternal mortality reflect an increase in obesity, age or fertility treatment in pregnant women? We don’t have access to the data that will tell us. Is the increase in maternal mortality related to California’s worsening fiscal status and associated cutbacks in services? We don’t know that either. We do know that the C-section rate has been rising dramatically all across the US. The C-section rate in California in 2006 was 31.3% almost exactly the same as the overall US rate. This is an increase from the US rate in 2003 of 27.5%, representing an increase of 13.8%.

Is the rising C-section rate responsible for the rising maternal mortality rate? Without patient level data we cannot know, but it certainly is a possibility. I have written in the past about the diminishing returns of an ever increasing C-section rate and predicted that there would be a point at which the risks to mothers would outweigh the benefits to infants. I await the release of the California report to find out if we have reached that point.