In this study of 36 #pregnant ppl with #COVID19, 4 showed infection and other pathological changes in the placenta. This correlated with fetal distress, even though all mothers were only mildly ill/asymptomatic. 1/
Why is effectiveness vs hospitalisation lower than against all infection? This is the opposite of what we see in larger studies of the whole population, eg. this PHE data… 2/
This is a follow-up to this older study in the same cohort. The older version of the study showed no increased risk of miscarriage following vaccination, but the follow-up time was shorter (10-12 weeks). 2/
Although the data from this study was reassuring, the limited follow-up time made it difficult to exactly calculate the miscarriage rate following vaccination, so an estimate was used.
After I wrote this thread about the potential effects of COVID vaccination in pregnancy and the lack of such effects in other vaccines, perinatal epidemilogist @deshaynef got in touch to tell me about some work she has done in this area... 🧵