The Schoenicks are proof that there’s more than one way to plan a family. After the birth of their first child, parents often agonize over how long to wait before moving on to number two or three. Will too much of an interval mean raising two kids with nothing in common? Will too little throw the household into chaos? In this country the average space between births is four years–the same span as among the hunter-gatherers, who typically delayed pregnancy by nursing around the clock for so long and staying so lean that it took them a long time to ovulate again. But some give birth to future playmates who are only one year apart. (Women can ovulate as soon as 27 days after they deliver if they’re using formula instead of breast milk.)
The American College of Obstetricians and Gynecologists recommends an interval of 18 months to two years. A study published in The New England Journal of Medicine in February found that infants born about two and a half years after a sibling were least likely to be premature or to be unusually small. Researchers who looked at 173,205 infants born to Utah moms between 1989 and 1996 found these undesirable outcomes were 30 to 40 percent higher among infants conceived less than six months after a birth than among infants conceived 18 to 23 months after a birth. They suspect that these babies suffered because their moms were still recovering from vitamin depletion, blood loss, reproductive-system damage–and the stress of caring for a newborn. Utah mothers who waited 10 years between children were twice as likely to give birth prematurely.
Older moms, concerned about infertility, often want to reproduce quickly. But younger parents may wait longer so that they have more time and money for each child. Tightly spaced siblings, after all, tend to perform worse academically and are less likely to enter and finish college, says Indiana University sociologist Brian Powell, an authority on the effects of spacing. And they can exhaust their parents. “It’s to everybody’s advantage to have only one child in infancy at a time in a family,” says anthropologist Helen Fisher.
Still, kids are remarkably resilient. Chicago lawyer Helen Friedli, 42, is No. 9 among 13 children her mom delivered in 18 years. Her siblings, who all completed postgraduate degrees, include five lawyers and one doctor. “The amount of affection children get from their parents is critical, but that’s not determined by spacing,” she says. And nature doesn’t always cooperate. “People can’t get pregnant like turning on and off the light switch,” says pediatrician Mark Klebanoff of the National Institute of Child Health and Human Development. “I don’t think people should get excessively concerned about spacing.” Children are rewarding–and hard work–whether they’re one or 10 years apart.
