In comparison to women who have never had children, women who have delivered a child may have a greater breast cancer risk that may continue for up to 23 years after their latest delivery, as per the study published in the journal Annals of Internal Medicine on Monday.

Hazel Nichols, assistant professor of epidemiology at the University of North Carolina at Chapel Hill’s Gillings School of Global Public Health, mentioned that they saw a pattern where risk was highest about five years after childbirth, and then it steadily reduced as time passes.

Yet after those 23 years, the risk appears to change so that childbirth then seems to be protective against breast cancer, according to the study.