I heard this on BBC Newshour but found this link for this thread. A neonatalogy research group in Barcelona has confirmed that babies register hearing very early in the fetal stage - 16 weeks. If you scroll down, you will see a review of the study where they show how this positioned the microphone. The women who volunteered certainly put up with a lot.
As for the study itself - I find the science fascinating, but also assume it will be used in the context of women’s rights issues. So it goes.