If you know you will have more than one child, deciding on when to have that second (or third) baby can be a big decision. There are a lot of advantages and disadvantages to spacing your kids close together (instant hand-me-downs!) as well as farther apart (who needs a mother's helper?).

Here's a breakdown by age of things to mull as you're looking ahead to your next baby.

Pros and cons of a 1-year age gap between children

Your kids may more likely become good buddies when they're so close in age. That said, so little time between children can be hard on you.

Possible benefits of a 1-year age gap

  • You'll become incredibly efficient. Yes, those first few years with two under 2 will go by in a sleep-challenged blur — but the upside is that you become quickly adept at diapering, bathing and all those other day-to-day tasks. 
  • Your eldest may be less bothered by the change. Your older child is too young to fully understand what all this means — so he may be less likely to act out or reject the new baby than if he was older.[1] Plus, because he hasn't had his parents all to himself for all that long, he may not expect as much attention or preferential treatment.
  • Your kids could become closer. While there may be more squabbles, kids so close in age can be closer emotionally, too, sharing friends and enjoying the same games, TV shows and activities.

Potential challenges of a 1-year age gap

  • It's hard on your body. Having another child so soon after the first means your body doesn't necessarily have sufficient time to recover fully. Your iron and calcium levels may be depleted, and you may suffer from prenatal anemia or just feel tired and run down. Some research has shown that getting pregnant again within a year of giving birth puts you at higher risk of giving birth prematurely.[2] Plus, you may be more likely to develop the baby blues after having a second child so quickly in succession to the first. If your first was born by C-section less than 18 months before your second arrives, it may be difficult (or dangerous) for you to deliver vaginally. All of this is why experts recommend waiting at least 18 months between pregnancies.
  • It's a lot of work! Adding to that sense of exhaustion? You have a very demanding toddler who still has many needs you need to meet. And the years of sleepless nights, diapers, breastfeeding and baby spit-up will run consecutively if the age gap between kids is this small.
  • Your attention is divided. It's more challenging to nurture the mother-baby bond when your hands are full with back-to-back babies.  
  • You can't pass down baby gear. Because your kids are so close in age, you'll probably need to invest in some extra baby gear, like a second crib and a double stroller.

Pros and cons of a 2-year age gap between children

At this point your kids are still close enough in age to share plenty of interests — and with a little more time before a second pregnancy, it's easier on you, too.

Possible benefits of a 2-year age gap

  • Your body is ready. When it comes to how prepared your body is for the next baby, a two-year gap is healthier for you than waiting less time: Your body has had enough time to bounce back from the last pregnancy.
  • It reduces risk of pregnancy complications. Experts recommend waiting at least 18 months between pregnancies because it reduces the risk of your youngest child being preterm or low birthweight (especially if you're over 35).
  • You've got this. At this point you won't have forgotten the basics of caring for a newborn, while at the same time you'll feel the confidence that comes from being an old pro.

Potential challenges of a 2-year age gap

  • Sibling jealousy might be more intense. Rivalry may be greater than with either a smaller or larger age gap: At the toddler age, your child not only demands center stage — but demands that stage be empty.
  • Your kids may act out. As a toddler, your older child doesn't like to share — and that goes for attention, too (especially yours!). So your tot may be more likely to be demanding and defiant towards you when a new sibling arrives.
  • Your child may regress. Most kids experience some regression after the birth of a sibling (think potty-training accidents, baby talk, thumb-sucking), but these behaviors are especially common in the toddler years.
  • It can be (temporarily) chaotic. Fussy newborn plus terrible twos can mean stress and disharmony are double in your house, at least for a while.

Pros and cons of a 3-year age gap between children

Now that your firstborn has graduated from the baby and toddler years, he may be a bit easier to take care of (most days). 

Possible benefits of a 3-year age gap

  • Labor may be safest. According to some research, you may have the lowest risk of labor complications when you have your second baby around three years after your first.
  • Pregnancy may carry less risk for you and your baby. Again, this time frame seems to be easier on your body versus having a baby earlier (when you haven't had as much time to recover) or later (when you're older and may potentially face age-related risks).
  • It's easier on you. A 3-year-old can (theoretically at least) entertain himself and in general show some independence while you're dealing with the little one. He's probably potty-trained, so you won't have to be dealing with diapers for two. Plus, your older child may be in preschool for some of the day, allowing you some snuggle time with your second child.

Potential challenges of a 3-year age gap

  • You've still got a lot on your hands. This can be a difficult age gap for parents, as the older sibling isn't capable of caring for himself but has needs that aren't as easily met as a younger firstborn's are.
  • Sibling jealousy can still be a problem. Your older child understands that he is getting less attention but can't cope with the feelings that realization engenders, and he may lash out at you or the baby. In fact, physical aggression tends to peak at around age 2 to 3.
  • Regression is still common. With the birth of a younger sibling, many kids at this age are apt to revert to baby behavior, like clamoring for diapers and babbling like a baby.

Pros and cons of a 4-year (or more) age gap between children

Once the memories of sleep-deprivation and diaper blowouts fade, many first-time parents start seriously mulling over when to turn their threesome into a foursome (or more). 

Possible benefits of a 4-year age gap

  • You'll get more one-on-one time with each child. Since the time-consuming aspects associated with having two younger children are fewer, you'll likely have more time to read, play and otherwise enjoy each of your kids individually.
  • Your eldest may handle it better. By 4 years old, firstborns are a bit more mature — which means they may be less likely to feel threatened, jealous or insecure with the arrival of a sibling. And since physical aggression is most pronounced between the ages of 2 and 4, your older sib is apt to be gentler with the baby, too.
  • You're at ease. You're less likely to sweat the small stuff when you've been a parent this long.
  • Your older child can help. Your eldest child is independent enough not to need your constant attention — which means he may be able to assist you in caring for the baby. And he may help in more subtle ways, too. For example, your younger child could pick up talking, reading and even potty training from her older sibling.

Potential challenges of a 4-year age gap

  • Birth complications may be more common. Compared to women who wait two years to conceive, the risk for labor or delivery complications may be higher (especially if you're over 35).
  • You might be a little rustier. With more time between babies, you might have forgotten some baby basics, like how to swaddle. And you may also miss the free time you've gotten used to at this point, since your older child is relatively self-sufficient.
  • Your kids may not relate as well. Trips to Disney World, movie night — your kids might not enjoy some of the same family activities as if they were close in age, which could mean you have to split activities with your partner.