This systematic review and meta-analysis examined fifty-two studies to look at how pregnancy-related factors might affect breast cancer risk in daughters. The researchers looked at maternal and paternal age, gestational age at birth, twin status, and maternal preeclampsia. The main goal was to see if these exposures were connected to breast cancer risk in the next generation.
The analysis found no clear associations for gestational age, twin status, or maternal preeclampsia. For maternal age, there was a signal of increased risk up to thirty years, but the statistical evidence was not strong enough to be certain. The possible link with paternal age disappeared when the data was broken down into subgroups.
The findings remain inconclusive overall. Uncertainty exists because of differences between the studies included in the review. Because the evidence is limited and not practice-changing, readers should not assume these factors cause cancer. More research is needed to understand these connections before any firm conclusions can be made.