100kg isn't a particularly large mass for an adult. Particularly not these days.And that's a pretty big birthing assistant! I didn't realize how tremendously different it was, though.
I mass ~100kg, and at 182cm tall, am not unhealthily overweight. If I get down to 90kg, I look and feel underweight.
BMI calculator says you're obese.
I think even more relevant is changes in birthing approaches. More friendly rooms (thus not full of hospital equipment) and especially water birth. If she's not in the center of the birthing pool that will have an even bigger effect.Allowing husbands to be present in the room when their wives give birth has a greater gravitational effect on a newborn than the Sun, Moon, or planets. I wonder if astrologers have taken this late twentieth century change in social norms into account in preparing their charts.