The postpartum recovery window as a determinant of maternal aging

Higher parity predicts an elevated mortality risk in many cohorts, yet the association is inconsistent across populations and poorly explained by existing mechanistic accounts. Accumulating evidence indicates that pregnancy transiently accelerates biological age and that the postpartum period represents a recovery window during which this acceleration partially reverses. When a subsequent pregnancy begins before recovery is complete, this normalization is truncated and the aging burden may compound across successive pregnancies. We propose that the interpregnancy interval, as the determinant of how much recovery occurs between pregnancies, is the missing variable linking reproductive history to the long-term maternal aging trajectory. We develop falsifiable predictions, identify the study designs needed to test them, and argue that reproductive spacing may be a modifiable determinant of the lifelong aging trajectory.