The reason that the guidance has changed over time is both because we now have stronger evidence that COVID infection is dangerous in pregnancy, associated with increased risk of preterm birth, stillbirth and baby needing intensive care… 4/
… *and* because of the mounting evidence on the safety of #COVID19#vaccines in #pregnancy. Too much too summarise in a single tweet, but data on >40k pregnant people from 4 countries, across 7 studies. Links to studies here… 5/
Finally, this question about long-term effects is one I am often asked, and it’s a fair one. But we have every reason to believe that, like other non-live vaccines given in pregnancy, there will be no (bad) long-term effects from this vaccine. Whereas there can be from COVID. 6/
Finally, I would like to call on anyone in the media who wants to interview someone about this issue to do the responsible thing and invite someone from @RCObsGyn or @MidwivesRCM, who know the data and science on this, rather than just stopping the Rolodex at random. 7/7
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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... 🧵
Let’s start by looking at the effects at birth. We now have four large datasets from three countries telling us that babies born after vaccination in pregnancy are normal. 2/