When a woman waits to start having kids for just an extra five years, from the age of 30 to 35, it can have profound consequences.
The biological difference is the most obvious one, though every woman will have a different experience. A woman’s fertility generally begins to decrease around age 32, so for most women, it will be more difficult to conceive at 35 than it would have been at 30. Fertility declines more sharply after age 37.
In addition to potential difficulties getting pregnant, miscarriages and a number of complications to pregnancy, including gestational diabetes and high blood pressure, are more common for women over 35.
But there’s a significant, positive effect of waiting to have kids, Elizabeth Gregory explains in “Ready: Why Women Are Embracing the New Later Motherhood.”
Women who delay having kids earn significantly more per year than women who start having kids earlier, and this effect shows up even in women who started families at 35 instead of 30.
Gregory, who directs the Women, Gender & Sexuality Studies Program at the University of Houston, used US Census data from 2000 to compare the annual salaries of women between the ages of 40-45 who had professional degrees and full-time jobs.
Those who gave birth to their first child at age 35 made more than $US50,000 more per year than women who had their first child at 20, on average. But even waiting just those five years from 30 to 35 was associated with a difference of an extra $US16,000 per year, on average. (It’s impossible to tease out cause and effect with a study like this; the data show an intriguing correlation, not a smoking gun.)
These higher earnings among those who delay having kids isn’t just for women with professional degrees.
Women who had their first child between the ages of 21 and 33 earned 6% more for every year they waited to start a family, Amalia Miller, an economist at the University of Virginia, reports in a paper published in the Journal of Population Economics. If Miller’s findings can be extended to women who had their first child at 35, that means a woman who waits five more years to start a family will be earning 30% more per year than if she started her family when she was 30, generally speaking.
Women who wait to have kids make more money because they have built up experience and progressed up the ladder in their careers, Gregory told Business Insider.
Besides higher salaries, women who wait until they’re at least 35 to have kids generally have accrued experience and clout at work that helps them create what Gregory calls a “shadow benefits system” to supplement official benefits for parents (or lack thereof). They may have lots of stored up vacation time, or may be able to negotiate more flexible work schedules or the ability to work from home, while more junior colleagues might not.
All this means waiting five years to start having kids can make a big difference for how much a woman earns in her career. Multiply that effect (and more) by all the women waiting even longer to start families, and the trend to delay parenthood becomes a really big deal.
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