After giving birth to a child, most women experience a period of temporary infecundability, or biological inability to procreate. Breast-feeding seems to have a major effect on how long this stage lasts. In the absence of breast- feeding, the break is less than two months. If breast-feeding is done often and for a long period, it may last one or two years. This impact is thought to be caused by a mix of neurological and hormonal processes that are triggered by suckling.