Why did maternal mortality in white women but not black women increase after 2020?

White pregnant women were more than three time likely to get the covid vaccine

Our colleague Clare Craig has posted about the new report by MBRACE on Maternal mortality 2021-2023.

If you read just the summary of the report everything appears to be just hunky dory:

There was a statistically non-significant decrease in the overall maternal death rate in the UK between 2020-22 and 2021-23. When deaths due to COVID-19 were excluded maternal death rates were similar between the two periods.

Note that this refers to overlapping time periods (2020-22 and 2021-23) which pollutes the statistical tests; this is typical of the sort of trick/obfuscation used in Government statistics reports during the covid era. But Figure 3 of the report (which provides a breakdown by different ethnic groups) tells a different story. Here is a screenshot, but the actual report allows you to download the data.

Also, Clare Craig notes that “For unfathomable reasons MBRRACE uses three year cohorts and the x axis shows the middle year. Therefore 2019 includes covid and 2020 includes vaccines.”

When we download the data we can more easily directly compare the rates of the two largest groups: whites and blacks.

The fact that maternal mortality rates for blacks have been significantly higher than for whites has long been recognised. But the interesting thing about this data relates to the years ending 2021 and 2022. In these two years the mortality rate for whites (12.2) was 26% higher than the highest rate (9.7) in any of the preceding 10 years including the main covid year 2020. In contrast, the mortality rates for blacks decreased.

Now we might have expected an overall increase in mortality after 2020 due to lockdowns and poor medical care during the covid era. But, why would that have caused the significant increase in maternal mortality rates of whites at the same time that maternal mortality rates of blacks was decreasing? It could be that staying away from hospitals improved mortality for blacks. However, an alternative and perhaps more likely, explanation lies in the comparative covid vaccination rates.

In England the covid vaccine was recommended for pregnant women in early 2021. According to UKHSA data, the number of pregnant women in England who, by October 2021, had received at least one covid vaccine dose by the time of delivery were:

1. White women: 41.3%

2. Black women: 13.3%

Of course, we know ‘correlation is not causation’ ….

The ‘good news’ is that, since there are approximately 660,000 pregnancies among white women in England per year, the increase in absolute number of deaths was only about 16 in total (increasing from about 64 to 81).