Baby gains about half a pound a week, so i would say if you go to 42 weeks your looking at an extra pound of weight...xx
No it won't keep getting bigger, after 40 weeks the placenta doesn't work as efficiently, hence them not wanting women to go over 42 weeks. Babies tend to actually weigh less at 41 weeks then at 40 weeks. So don't worry about your baby getting too big if you go overdue.
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