Previously, scientists have thought women’s ovarian reserve – effectively the size of their egg bank – came down to genes or their race.
But the conditions women of a similar ethnicity and social background lived through as girls may also have a profound effect, the senior author of a study published in the journal Fertility And Sterility has said.
Professor Gillian Bentley, an anthropologist from Durham University, explained how a study looked at a group of 129 middle-class Bangladeshi women aged 35-59 from Sylhet.
Some of them had remained in Bangladesh, some moved to London as children and others migrated there as adults. A group of 50 white British women were also part of the study.
The levels of four hormones in their bodies were read, and the researchers found the women who stayed in Bangladesh or moved to the UK as adults had a similar-sized ovarian reserve.
The Bangladeshi women who moved to the UK as children and the British-born women had a much larger ovarian reserve than the other groups, indicating a later menopause.
Professor Bentley said the cause was likely to be the stress of a body under attack from disease during childhood having an impact on future reproductive capacity.