I think the last few weeks before the end of the pregnancy can be very uncomfortable for working women. They have fatigue. Their balance is bad. They're probably more in danger of having accidents at work. They have backaches.
There's a lot of evidence that women are hugely uncomfortable in all sorts of welding jobs during those last few weeks. As I said earlier, 80% of women in these physically demanding jobs stop by 28 weeks, so those last 15 weeks are really barely covered by that.
I would certainly support women being able to take their maternity leave earlier, but it doesn't have a huge effect on the outcome of the pregnancy in terms of the child's health, other than it may stop some lighter-weight babies from being born. On the whole, that's for the woman's health and comfort rather than the baby's.