Quick follow-up: UK Vaccines and Pregnancy

I'm concerned

***Jan 7 2022: See Part 3 for some updated estimates

My post from a few minutes back attempted to be cautious in drawing any conclusions based on the data on vaccinations and stillborn births in the UK. Please read that post 1st before this one.

The primary reason for caution was not knowing how age was impacting my analysis. As I just walked to lunch, I realized that data I shared in that post will allow me to estimate that impact. Namely, these two pieces of data:

Together, I can estimate what the difference between fetal mortality rates should be based solely on the ages of the women in the Vaccinated vs. Unvaccinated cohort:

So, based purely on the Vaccinated women being older, we would expect them to have fetal death at a rate (5.92/5.7) = 1.04 that of Unvaccinated women. This does not account for the time of vaccination and time of fetal death as I discussed in the last post. What I need to do now is modify my equation for the expected stillborn rate for Vaccinated women:

[28.5% (women vaccinated before 3rd trimester) x 1.04 R] + [71.5% (women vaccinated during 3rd trimester) x 1.04 R x 53% (fraction of stillbirth expected in 3rd trimester)] =  69% R

As you can see, I have replaced simply multiplying by R (the assumed rate of stillborn among unvaccinated) with 1.04 R to account for the vaccinated being older.

Therefore, to the best of my ability to estimate the impact of age, I conclude that Vaccinated women should be reasonably expected to experience stillborn births at a rate of 69% of Unvaccinated women (31% lower). Instead, the UK reports shows them at only ~7.5% lower. This would lead me to a lower, but more well founded, estimate of additional risk of stillborn to women by being vaccinated by ~23%.

Again, please correct any errors in my thinking. I truly want to get this right and only raise a concern if one is warranted.