Covid vaccination and miscarriage

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2805029

JAMA came out with a paper in late spring 2023 trying to debunk the theory that covid vaccines during pregnancy lead to increased miscarriage rates.

Time period evaluated: November 1, 2021- June 12, 2022. This is concerning because it was a 7 month trial, nearly a year after most people received their first 2 vaccines, and the study clearly says they were only looking at people who received a 3rd vaccine booster during this time period.

The setting: “Data for this case-control surveillance study came from 8 VSD sites (Kaiser Permanente: Washington, Northwest, Northern California, Southern California, and Colorado; Denver Health; HealthPartners; and Marshfield Clinic). People in the VSD population aged 16 to 49 years with a pregnancy 6 to 19 weeks’ gestation between November 1, 2021, and June 12, 2022.” They looked at women who received a booster in a 28-42 day window post vaccine. Well, what about the women who miscarried prior to day 28? Or after day 42? Shouldn’t the study have ran for the duration of the entire pregnancy and looked at not only miscarriages but also at still births that were term babies? What about the women who miscarried at 20 weeks? 21 weeks? Anytime prior to viability?

The data:

In the primary data looking at 28 day time periods, there were 285 079 pregnancy patients with 14, 226 (12.1%) that resulted in spontaneous abortion cases.

Secondary analyses included 103 156 unique pregnancies across five 42-day surveillance periods from November 1, 2021, to May 29, 2022; 89 830 (87.1%) remained ongoing pregnancies and 13 326 (12.9%) ended in a spontaneous abortion. Secondary analyses using a 42-day surveillance period included a total of 182 025 pregnancy periods (13 326 cases and 168 699 ongoing pregnancy-period controls), with 11 669 (6.4%) having received a third mRNA vaccine and 12 494 (6.9%) having received any COVID-19 vaccine booster in a 42-day exposure window.

Here is the problem with this data. First off, most women had already had 2 vaccines prior to the 3rd booster studied in this data. The data period was short. It only looked at 8 hospitals, and it was not women enrolled in a study, it was ELECTRONIC HEALTH RECORDS that were reviewed retrospectively. How many less women got a 3rd booster compared to the first 2 shots? What does the retrospective data look like in women 6-19 weeks gestation during the deployment of shot 1 and 2? We need a comparative study for that in and of itself. It also fails to look at any pregnancy loss beyond 19 weeks. What about stillbirth rates at the time of delivery? Again, cherry-picking data to make these appear safe is not good robust credible data. But I guarantee you that OB/GYN will cite this study as why women can safely vaccinate during pregnancy.