I always knew I wanted to have at least two kids. So, after I had my first child, I didn't have to decide whether or not have a second, but when. In other words, I had to try to figure out what's the best age gap between siblings.
Of course, child spacing isn't 100% in anyone's control. Surprise pregnancies do happen to a lot of people (in 2011, 45% of pregnancies in the United States were unintended, according to the Guttmacher Institute). But my partner doesn't make sperm, so instead of worrying about a "surprise" I had to worry about contacting my sperm donor and setting up our monthly vial-transfer rendezvous. And, of course, I didn't know exactly when I'd get pregnant. And that figured into the calculations.
A 2011 study published in Journal of Human Resources surveyed over 12,000 parents and found that when age gaps were greater, older children benefited academically (and not to the detriment of younger children). And a 2006 study published in Journal of the American Medical Association found that "interpregnancy intervals shorter than 18 months and longer than 59 months are significantly associated with increased risk of adverse perinatal outcomes." I originally thought I wanted kids about two years apart. So when my first was 1, I started thinking about trying again.
My decision to start trying was followed by a stall period. A difficult first pregnancy had me doubting my ability to keep up with an energetic toddler under the weight of crushing fatigue. But, eventually, I talked myself into it. The sperm donor legal paperwork took a few months, and getting pregnant took a few more. As a result, my kids are three years and five months apart.
I'm so happy with how everything turned out. Because, in my (limited and clearly biased) experience, I've come to think that three years is the perfect age gap. While that might not be true for everyone, here's why it's true for me and my family:
Because You Only Have One Kid In Diapers
Ok, this isn't 100% true. My older son, who I'll call Emmett, was potty trained before he was 3, before I got pregnant. And then, as a response, reaction, or toddler-size protest to my pregnancy, he un-potty-trained. (Thankfully, only in the pee department.)
All through the nauseating first trimester, I didn't have to deal with poop-filled diapers. Accidents, yes, until I gave up and put him back in pull-ups full time, which turned out to be easier. And, once the baby (who I'll call Tyler) came, and my energy returned and I could be more present in Emmett's life, he re-learned how to pee in the potty pretty quickly.
Because The "Big Kid" Can Walk Places
The baby is going to need to be carried. The baby's gear is going to need to be carried. The big kid's gear is going to need to be carried. The groceries, library books, and blankets will need to be carried. If, even sometimes, the big kid can propel themselves in the direction you want, it's a huge help.
Because You Don't Have To Push Around A Double Stroller
Yes, you can if you want to. Or you can get a sit-stand, or one of those ride-along-board attachment things. But you don't have to. And when you have two children, the ability to minimize purchases and just, you know, stuff, is always beneficial.
Because The "Big Kid" Can Follow Some Simple Safety Rules
Again, this statement comes with a few caveats, like "when he feels like it" or "for a few seconds." But that makes a big difference! If I can, even sometimes, trust the big kid to hold on to the side of the overloaded stroller, that makes it easier to cross the street. If I can ask the big kid not to whack the baby, I can, if everyone's in a good mood, close my eyes for a moment while I splash water on my face, hoping that a quick scrub will adequately replace a shower two days in a row.
Because The Kids Are In The Same Age Range For Activities
With a baby and a 3-year-old toddler, I could go to story time at the library. I think if I had a 5-year-old child, though, they would have been bored. With a baby and a 3-year-old, I can go to the little kid's playground. As they get older, a 1-year-old and a 4-year old will both like the children's museum. A 2-year-old and a 5-year-old both think the swings at the playground are the best.
Because You Can Reuse Clothes...
At three years apart, they won't be in the same size clothes until at least middle school, so you can get double use out of everything.
(And, yes, I hear some of you saying, "But only if they're the same gender." To which, I reply, "Only if you think boys can't wear dresses or the color pink." And, well, they can.)
... & Car Seats
By the time baby comes along, the big one will be done with the bucket car seat. Then, when the baby is growing out of the bucket, the big one will be ready to upgrade to a booster, so baby can have the rear-facing convertible.
Let's face it, car seats are expensive, especially the baby and convertible seats. Yes, you'll probably eventually need two booster seats, but those seats are way less pricey. (And, of course, stay up-to-date on any potential recalls or changes in car seat safety, as that would impact whether or no you can have your child use their sibling's car seat.)
Because The "Big Kid" Can Understand That A Baby Is Coming
My son knew we were trying to get pregnant. At age 2 he could count to two, so he helped me count the lines on my pregnancy test. He went with me to almost all of my prenatal appointments with my midwife and doctor. And he was there to watch his brother enter the world. With a smaller age gap, the arrival of a baby can seem very sudden and shocking. With a three year age gap, my son knew what was going on and had lots of time to get ready.
Because The "Big Kid" Can Hold The Newborn...
One of my favorite photos of my kids is of Emmett holding Tyler just hours after Tyler was born. Yes, I was right next to them, supporting Tyler's head, but Emmett was really holding him, doing his best to be careful and take good care of his tiny baby.
... &, If They Want, Even Cut The Chord
Since I had a home birth, Emmett was there for Tyler's birth, and his little hands were just big enough, and just skilled enough, to attempt to cut the cord.
(It turned out his tiny hands weren't quite strong enough, so he got some help, but he still felt like he did it all by himself.)
Because A Non-Matching Nap Schedule Can Be A Good Thing
Yes, it's hard when the kids' nap schedules don't line up. Or, in my case, when the big kid gives up on napping entirely before the baby comes, so I never got a break at all.
But, the staggered nap schedule turned out to be a good thing. One of the hardest things for the big kid is that they no longer have the parent's undivided attention. So, Tyler's nap time became a chance for Emmett, who craves attention more than anything else in the entire world, to get some one-on-one time.
Buckles, K. S.; Munnich, E. L. (2011) Birth Spacing and Sibling Outcomes, Journal of Human Resources, https://www.sole-jole.org/12106.pdf
Conde-Agudelo, A.; Rosas-Bermúdez, A.; Kafury-Goeta, A. C., (2006) Birth spacing and risk of adverse perinatal outcomes: A meta-analysis. Journal of the American Medical Association, doi: 10.1001/jama.295.15.1809