Mine did go up in size,with one exception.Don't knowif their weights had anything to do with whether they were boy or girl,possibly,but also how late they were.Mine were all late but one and she was the smallest,even though only three days early,so not really early.
1st 7lb11.5oz boy 5 days late
2nd 8lb 2oz girl 5 days late
3rd 8lb 5oz girl 9 days late
4th 8lb 7oz boy 7 days late
5th 7lb 11oz girl 3 days early
6th 8lb 11oz girl 8 days late
7th 9lb 4oz boy 11 days late