Sisters' Late Babies Might Help Brothers Live Longer

There's a fascinating link between sisters having babies later in life and their brothers living longer. This isn't about lifestyle choices but likely about genes. Studies show that women who have children in their 40s and 50s without fertility help tend to live longer after menopause. This got scientists curious about how this might affect their brothers. Researchers looked at two big groups of people from the past. One group was 1. 6 million Utah Mormon pioneers and their descendants. The other was 400, 000 people from Quebec. In both groups, birth control and fertility treatments weren't common. They found that brothers with three or more sisters, including at least one who had a baby at 45 or older, were up to 22% less likely to die after age 50. The brothers' wives didn't see the same benefit, which points to genes being the key factor. This study also confirmed that women who have babies later in life tend to live longer. For example, Utah pioneer women who had their last baby between 41 and 44 cut their risk of dying after 50 by 6%. Having a baby at 45 or older reduced that risk by 14%. Similar patterns were seen in Quebec. Having babies later in life isn't as rare as you might think. In 2020, nearly 1, 000 American women aged 50 or older gave birth. Some women even have babies in their 60s. This trend is part of a bigger picture where American women are waiting longer to have children. In 2023, the average age of first-time mothers in the US was 27. 5, up from 21. 4 in 1970.