, outcomes after subsequent births are not independent of previous births. Finally, in a sibling-controlled study it would be difficult to adjust for the time-varying confounding by parity, as women tend to slightly gain weight over time.
,outcomes after subsequent births are not independent of previousbirths. Finally, in a sibling-controlled study it would be difficultto adjust for the time-varying confounding by parity, as womentend to slightly gain weight over time.