What is the ideal gap between two pregnancies

A funny thing happens in groups of friends who welcomed their first children around the same time. By your kids' first birthdays, you may notice said friends splitting off into one of two categories: those who've announced they're pregnant with baby number two and those who are wondering if it's too soon to have the next one.

Not all round-two expectant moms are intentionally ahead of the curve on family planning (some of us were, ahem, surprised!) and many worry about the effects a second baby will have on their family at that point—will the firstborn be shortchanged on attention? Will we get eight hours of sleep any time in this decade?

There's also your health to consider: A 2018 study published in the journal JAMA Internal Medicine found that women who wait fewer than 12 months between giving birth to one child and the conceiving the next face greater risk of illness, death, and spontaneous preterm delivery.

"If the mother is in good physical and emotional health, I generally recommend she waits [to conceive] until her [youngest] child is about 18 months," says Patrice Harold, OBGYN, director of minimally invasive gynecology at Detroit Medical Center's Hutzel Women's Hospital.

The World Health Organization recommends a minimum of two-year intervals between pregnancies. "Studies have suggested that intervals shorter than 18 months are associated with increased risk to the infant—including preterm birth, low birth weight, small size for their gestational age, and NICU admissions," notes Dr. Harold.

Rachel Firk, a mom of seven whose oldest two were born 14 months apart, wishes she had waited 2 years between kids. "My oldest didn't get much of a chance to be a baby: He was 5 months old when I got pregnant, and I was weak and had severe morning sickness, so I had to stop breastfeeding him," says Firk, an editor at parentingpod.com.

"When the baby was born, my older son was expected to act as the 'big brother' but he was a baby himself, and didn't have the skills or ability to understand the needs of others," she adds. "But I did learn my lesson—my other kids were all born 3 years apart."

On the flip side, longer intervals—more than 59 months between pregnancies—have been associated with increased risk for mothers, such as developing preeclampsia, says Dr. Harold.

Most women we talked to about timing pregnancies say they can't imagine a better situation for their family than the one they've got, but they have plenty of advice about having offspring close together or farther apart. If you're feeling conflicted about how long to wait, consider their experiences—they might help you decide when to have a second baby.

Here's what to expect from different sibling spacing scenarios:

The Playground Wisdom: Rapid-fire family additions means condensing the time you spend in baby mode. This can be a good thing—the nuances of tummy time and teething are fresh in your mind when number two (or three!) comes along. "I was already doing diapers, so the learning curve was not that big," says Janerl Lampson, of Bakersfield, California, whose first two children are 16 months apart. "I would have loved twins—I'm the kind who says, if you're already doing it, you might as well do it more." Women who tried for a long time to conceive their first child or those who marry after 30 may be motivated to pick up the baby pace before that pesky biological clock becomes a factor.

The Highs: You may be rewarded within a year or so with kids who entertain each other well and are nicely in sync when it comes to toys and activities. Many moms also find that kids under 2 tend to be less jealous of a new sibling. "My girls are always with each other," says Dara Federman, a Brooklyn mom of two, ages 3 and 2. "Eliana said the other day that she wants to live with Leah forever."

This may be the most affordable option: While you may dread double costs with back-to-back kids, plenty of activities such as dance classes, camps, and even some preschools offer discounts for younger siblings. The biggest relief may come at college time. Families with two or more kids in school at the same time are generally expected to make a smaller contribution to tuition, which in turn could lead to more financial aid in the form of grants and loans.

The Lows: Hello, chaos. "The first two years were really tough," says Susan Hayden, of Seattle, the mother of Charlie, 5, and Clara, 4. "Someone was always sick or not sleeping. I think I missed out on really enjoying a lot of their stages because we were always in 'crisis mode.'"

Your marriage may get tested in these early days, too, with both parents feeling spread thin by the treadmill of feedings, laundry, and sleepless nights.

Expert Wisdom: Watch for signs of jealousy in your older child. "A 1- to 2-year-old may not be able to articulate his feelings or even understand why he's confused and angry," says Valerie Maholmes, Ph.D., a child-development expert at the National Institutes of Health's Institute of Child Health and Human Development. Take care to cuddle both kids so no one feels left out. "When you're cuddling the baby and your older child is in the room, you can say, 'Let me tell you about your big brother—he knows how to do lots of neat things!' Then give some examples like stacking blocks or kicking a ball," says Adele Faber, coauthor of Siblings Without Rivalry.

Harmony-at-Home Tip: Ask for help—from your partner, your parents, or a babysitter who can offer both a break for you and some extra attention for your toddler. "Take things slower," says Courtney Kennedy, of Emmaus, Pennsylvania, the mom of three closely spaced kids. "You'll need every ounce of energy to keep yourself and the kids happy."

The Playground Wisdom: This close-but-not-too-close gap is meant to preserve everyone's sanity. You and your husband may have even found time for regular date nights again.

The Highs: With your older child heading off for preschool, you'll get the freedom to bond with your new bambino. "I didn't realize how nicely the spacing would work in terms of individual time with each of my children," says Jennifer Page, a Tulsa mother of three kids spaced three to four years apart. "It's funny how different the kids are one-on-one as opposed to when we're all together."

Meanwhile, siblings are still close enough in age to share common interests, and many moms say the older child is a built-in mentor. "I'm always surprised at how much further ahead A.J. is than Kobe was at the same age," says Kelley Thompson, of Flower Mound, Texas, about her 4- and 7-year-old sons. "A.J. has a big brother to keep up with. He walked earlier, plus he's showing much more finesse at soccer, thanks to Kobe's teaching him what to do. Now they actually play together."

Careerwise, a 2- to 4-year age gap between kids may be ideal, assuming that you're doing classic maternity leaves and then returning full-time to your job. "This spacing let me concentrate on learning to be a mother for a few years while at the same time continuing to work hard at my career," says Mary Plaza, a Basking Ridge, New Jersey, insurance consultant and mother of three kids born three years apart. If you want to stay home until the kids are school-age, a tighter spacing is best for consolidating your career time-out.

The Lows: This revolving door—from baby to toddler mode, and then back again—can make you feel like you're in a very smelly remake of Groundhog Day. "Except for a few months along the way," says mom-of-three Page, "I have been changing diapers now for almost 10 years!" It can be especially vicious during naptime—your older child will be outgrowing his siesta just when you really need that afternoon break again.

It's also tough to ask for babysitting help when you have a rambunctious toddler and a new baby. "When my older child was little, finding someone to watch her for an hour or two was a snap. Family would line up to offer," says Jeri Ann Hall, a Memphis mom of two kids two years apart. "But a toddler and a baby—and when they get older, a 5-year-old and a 3-year-old—well, no one flat-out refuses, but they definitely make it clear they should be our last resort."

Expert Wisdom: Your firstborn was used to having you all to herself and now, whenever you're not free to play with her, she may become frustrated and pull some mean-kid moves on the new baby. Your reactions to her behavior can nip sibling rivalry in the bud. "Constantly telling your toddler 'No' may foster jealousy, because you'll be seen as taking the baby's 'side,'" says Linda Sonna, Ph.D., a child psychologist and author of The Everything Parent's Guide to Raising Siblings. Immediately discipline any aggressive acts, but quickly shift the emphasis to showing big sib how to handle—and enjoy—her new brother or sister.

Harmony-at-Home Tip: Getting your preschooler to help with the baby makes her feel like an important member of the family. "Megan liked getting bottles, diapers, and wipes," says Page. "We'd also sing songs to calm Macy when she cried, and I even assigned Megan 'babysitting' duties, like dancing while Macy was in her bouncy chair."

The Playground Wisdom: There are big winners with this spacing. Your kids each get the benefits of being an only child—lots of individual attention—but also the companionship of a sibling, even if they're not super tight. Meanwhile, you get to focus on each child with more freedom. "I definitely feel like I'm getting to know my kids as individuals," says Mary Ann Guman, a mother of three from Bethlehem, Pennsylvania, who had an eight-year break between her firstborn and her second. Lisa Laurente, of Bakersfield, California, who has three kids—ages 12, 10, and 5—agrees: "A large gap between children has allowed me to cherish the moments I have with my youngest child."

The Highs: Like Cher on a comeback tour, you're a little older but smarter and more confident. "I'm not as frazzled as I was with my two older children," says Laurente. "I have a more patient take on parenting." Your partner will likely feel the same way too. As a couple, you've had years to practice being a united front for the kids while also making time for each other, so this spacing may be the easiest on your marriage. Your firstborn may get a boost too. Laurente says her older kids were mature enough to really pitch in. "They learned to be more independent and help each other."

Meanwhile, don't write off the buddy potential. "I didn't know whether a 4-year-old and 10-year-old would want to spend a lot of time together, but the kids play, and sometimes fight, like the best of friends," says Lachelle Nettles from Dripping Springs, Texas. Your little one gets a more sophisticated mentor than he would with a sibling closer in age. As they grow up together, the older child can help guide his younger sibling through the world of playground rules, schoolwork, cliques, and lots more.

The Lows: You're commuting every day between Kid Nation—with grade-school obligations and evening Little League—and Planet Baby, which requires that you carry a cubic ton of gear, and likely a fussy infant, everywhere you go. "It was quite an adjustment," says Laurente, of returning to diapers and naps after such a long break. "I didn't think about how exhausted I'd be trying to entertain a toddler while attending baseball games." That may mean less time and energy for baby-friendly "Mommy and Me" activities.

Financially, this spacing has some downfalls. Your stroller and car seat will be out-of-date, so you'll need all new gear.

Expert Wisdom: Forget jealous—your older child might act positively bitter. "The arrival of a new baby can be more difficult for someone who's been an only child for a long time," says Dr. Maholmes. "You have nine months to prepare him; use this time to talk about all the good and potentially tough changes coming."

Harmony-at-Home Tip: The baby will get plenty of the spotlight, so remember to dote on your former only. "Abby loves to read bedtime stories to her little sisters," says Guman, "but we also give her special privileges like letting her stay up a little later at night. She likes to just hang out with us."