The Royal College of Obstetricians and Gynaecologists (RCOG) was in the news yesterday encouraging pregnant women to get vaccinated against Covid by quoting new data showing that “nearly 20% of the most critically ill COVID-19 patients are pregnant women who have not been vaccinated”. According to their website:
Since July, one in five COVID-19 patients receiving treatment through a special lung-bypass machine were expectant mums who have not had their first jab.
Pregnant women have been treated with a therapy, called Extracorporeal Membrane Oxygenation (ECMO), used only when a patient’s lungs are so damaged by COVID-19 that a ventilator cannot maintain oxygen levels.
Out of all women between the ages of 16 and 49 on ECMO in intensive care, pregnant women make up almost a third (32%) – up from just 6% at the start of the pandemic, March 2020.
The numbers from ICNARC back up the claim that pregnant and recently pregnant women have been admitted to ICU with a positive Covid test in greater numbers during the Delta surge than previously.
However, what the news stories don’t tell you is that the mortality rate since May among pregnant women admitted to ICU with Covid is around a tenth of that of non-pregnant women aged 16-49, 1.4% versus 14%, even though their average age differs only by around five years. It is true that the median age differs by a bit more, seven years, and the interquartile range reaches up nine years higher. This may explain much of the difference. Nonetheless, ten times higher is a lot and the age difference is unlikely to explain all of it so that pregnant women would come out at higher risk once age is accounted for. In terms of absolute numbers, just three pregnant women have died with Covid in ICU since May, versus 127 non-pregnant women aged 16-49.
In addition to this, the mortality rate among pregnant women admitted to ICU with Covid since May is less than half what it was between September 1st 2020 and April 30th 2021, 1.4% versus 3.6%. Meanwhile, the mortality rate in non-pregnant women aged 16-49 has declined only 27% in the same period, from 19.1% to 13.9%. Yet the vaccination rate is likely to be substantially higher in the non-pregnant than in the pregnant owing to greater wariness about vaccination among pregnant women.
The reasons for the increase in Covid ICU numbers among pregnant women since the summer are unclear, though I understand ICU, and ECMO in particular, is prioritised for younger people. However, put in the context of the mortality rate compared to non-pregnant women of a similar age, and compared to earlier in the pandemic, the figures cease to be so alarming, while the role of the vaccines becomes much less clear. There is nothing here that I can see to suggest that Covid is especially deadly for pregnant women, or that vaccination should be an urgent priority for them.
Stop Press: Pathologist Dr. Clare Craig has been tweeting about this story: “Mortality rate for those on ICU is 10 fold lower in pregnant women than non-pregnant.”
