Steve Kirsch is a well-known covid troll. https://duckduckgo.com/?q=%22Steve+Kirsch%22+misinformation&t=hy&va=g&ia=web

The journal article he is referring to cites no warnings and indicates a cautious optimism, but calls for further study. Characterizing it as "no evidence that vaccines are safe for pregnant women" is Russian Troll level misinformation.

Some quotes from the article:

"These are reassuring data based on reports from pregnant women mostly vaccinated in the third trimester."

"In addition, rates of local and systemic reactions after vaccination among v-safe participants who identified as pregnant were similar to those in a larger group of nonpregnant women, which suggests that the physiologic changes in pregnancy do not materially affect such reactions."

"With the pandemic ongoing and pregnant women at high risk for serious illness if infected with Covid-19, vaccination is a critical prevention strategy."

https://www.nejm.org/doi/full/10.1056/nejme2107070