Meta-analysis is even trickier when different studies use different definitions, different data sources or different verification criteria.
However, the article implies that the statistical methodology here was quite sound. I expect the Abortion Industry to come down on it with a blizzard of obfuscation, shuffling and denial in 3 - 2- 1 . . . . .
I’d think the Chinese study would be MORE accurate than the others. They’d have more complete records about abortions a woman has had.