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: