When to Have a Second Baby, According to Parents and Experts

A funny thing often 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 expecting baby number two and those who are wondering if it's too soon to have another.

Not all round-two expectant parents 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?

Research suggests waiting 18 to 24 months between pregnancies. Patrice Harold, OB-GYN, director of minimally invasive gynecology at Hutzel Women's Hospital in Detroit, generally advises birthing parents to wait until their youngest child is about 18 months, if they are "in good physical and emotional health."

"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. One such study published in JAMA Internal Medicine found there can also be a risk to the pregnant person's health.

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

It can be a tough decision to make but most people we talked to about timing pregnancies say they can't imagine a better situation for their family than the one they've got. They also have plenty of advice about having offspring close together or further 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.

Less Than 2 Years Apart

The pros

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.

You may also 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 parents 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. "Eliana said the other day that she wants to live with Leah forever."

Another plus: 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 multiple siblings attending.

The cons

"The first two years were really tough," says Susan Hayden, of Seattle. "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.'"

If you have a partner, your relationship may get tested in these early days, too, with both feeling spread thin by the treadmill of feedings, laundry, and sleepless nights.

Tips to keep in mind

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., CAS, chief of the pediatric trauma and critical illness branch at the Eunice Kennedy Shriver National 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.

And 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, a mom of three closely spaced kids. "You'll need every ounce of energy to keep yourself and the kids happy."

2 to 4 Years Apart

The pros

This close-but-not-too-close gap is meant to preserve everyone's sanity and allow for more time with each kid. "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, Oklahoma 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 parents 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. "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 a classic parental leave 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.

The cons

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 their siesta just when you really need that afternoon break again.

It can also be 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."

Tips to keep in mind

Your firstborn was used to having you all to themselves and now, whenever you're not free to play with them, they may become frustrated and pull some mean-kid moves on the new baby. Your reactions to this 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 the older one how to handle—and enjoy—their new sibling.

Also, getting your preschooler to help with the baby can make them 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."

5 Years Apart or More

The pros

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 agrees: "A large gap between children has allowed me to cherish the moments I have with my youngest child."

As a parent, you'll likely also be more confident because you've had a lot more practice. "I'm not as frazzled as I was with my two older children," says Laurente. "I have a more patient take on parenting." 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 they 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 cons

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 activities.

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

Tips to keep in mind

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."

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."