Answer: that the well-off have less regard for the poor than for livestock.
In this excerpt, Jonathan Swift argues that men have little concern for pregnant women of low classes, because the well-off have no regard for the poor. He exaggerates this point by comparing the women to livestock. He argues that a man would never kick or beat a pregnant mare or a cow for fear of miscarriage, and that perhaps women could at some point become valued enough to not be kicked when pregnant. The analogy implies that women are considered less important than livestock.