I read the same article just a few minutes ago. I think the idea was kind of a variation on the "thrifty gene" theme. If the baby in utero senses that carbs are super scarce "out there", it is going to become a carb hoarding machine.
Nowhere was pigging out on sugar advocated for pregnant women. Just maybe that pregnancy is not the best time to be seeing how low you can go on the VLC. Some sweet potatoes and fruit perhaps?