I wouldn't call that a punchline, that's just one of the stated observations. This would be closer to the punchline: “Our study confirms sex-specific behaviora

I wouldn't call that a punchline, that's just one of the stated observations. This would be closer to the punchline: “Our study confirms sex-specific behavioral changes in offspring as a result of these exposures, highlighting the fact that exposure to these chemicals should be avoided during pregnancy” But the article is short enough to read in its entirety. I find all the observations alarming, not just that one, given how prevalent BPA use has been in the past decades.