Sunday, June 14, 2009

Maternal mortality in NY state under review

The Poughkeepsie Journal notes efforts in NY state to investigate rising maternal death rates and notes that they have risen along with cesarean rates.

A few thoughts about this: it's easy to say "more women have cesarean sections because more women are high risk" (this is essentially what one OB in the article says). Very true - sing it with me, "Correlation does not imply causation". (By far the most important thing you learn in epidemiology.) High-risk women are more likely to have c-sections, and also more likely to suffer serious complications. But research also shows that cesarean section rates have risen for ALL women in ALL risk categories. So yes - it's not just that there are more high risk women, it's that there are more c-sections done on them.

I also wish the article had been willing to make it clear - c-sections DO carry a higher risk of maternal mortality. Maternal mortality is very rare - that's why it's measured per 100,000 (vs. infant mortality, which is measured per 1,000), so an increase may not be quickly visible because the rise in absolute numbers is very small. But if we get to a 40% cesarean rate, or 70% cesarean rate, or 100% like in some places in Brazil - we may not be able to say for sure which deaths were caused by cesarean, and which would have happened anyway, but it will be statistically guaranteed that some women will die from unnecessary cesarean surgeries. It doesn't really seem debatable.

Finally, as a caveat to all this and the entire article - I was curious to know whether New York state maternal mortality reporting has changed in the decade in question. Many states have adopted new death certificates and new reporting rules that have really upped the number of pregnancy-related deaths reported. The changes in reporting have made it really challenging to say anything reliable about national trends, and I wonder if the same holds true for NY.

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