I (and several others it seems) failed to take into account the short 2.5 month period during which the data were collected for this study. That means women vaccinated in their first or second trimester did not have enough time to have a full term pregnancy. The early miscarriages were logged, but because the study only looked at completed pregnancy outcomes, no full-term births for those inoculated early in pregnancy had time to occur.
So the miscarriage rate, compared to the rate of normal births, cannot be calculated from these data.
But 4 months have elapsed since the data collection ended. So CDC now has 4 more months of data, and the necessary calculations could be made at this time or in the near future. Then we would know about the benefit vs risk in pregnancy.
Please excuse my error.