A long term study published today in the Proceedings of the Royal Society B shows that certain factors in early childhood affect when a woman is likely to get pregnant for the first time later in life.
The scientists used data from the National Child Development Study, which has an ongoing group of people who have been tracked since they were between 3 and 9 years old.
Decades later, they found that four factors moved the date at which the women had their first babies forward — not being breastfed, having parents who were not as involved in her upbringing, having an absent father, and moving houses frequently.
The effect held up after factoring in education and socioeconomic status.
What’s going on here?
The researchers think that early stress can make small changes to a girl’s reproductive biology. It’s not the first time we’ve seen this idea — remember a few months ago, studies showing girls from middle class homes in which father wasn’t present, or with working moms were more likely to go into puberty early?
The evolutionary explanation: if early life is stressful, it signals to the person, way back in their “old brain” that they should get out there an make babies because the window may be limited (they might not live as long, for example).
I buy the overall theory, but I don’t think any of us has to worry about the particulars. Not being breastfed is not inherently more stressful to a child — my guess is that it’s confounded by other related variables. Unfortunately you can’t isolate breastfeeding from the rest of the picture for a study like this.
As for the rest of it, sure, stress affects our kids. But remember, it’s not the events in our child’s life that matter as much as how we handle them. So while moving or being a single parent might overall contribute to stress in the house, every family handles this differently and it’s far from being the be-all-end-all.
Each “factor” bumped up the age of first pregnancy by about 6 months — significant but not drastic.
Our goal isn’t to eliminate stress in our kids lives (impossible). So don’t cancel your move just yet.
image: flickr/pink sherbet