Getting Prepared for the Next Baby: Optimal Birth Spacing

The Full Belly Sisters are 21 months apart in age.
This guest post comes from brilliant doctor, wonderful mama, and decades-long friend to the Full Belly Sisters (she and I met in eighth grade!), Allison Bryant. Many thanks to her for sharing her personal and professional expertise!

I have come to the realization that I am, in fact, a mother of two.  And that two is, as a rule, more than one.  As obvious as this sounds, it’s taken more time than I’d thought for these messages to sink in.  So far, it’s been amazing and fun and breathtaking. And difficult.  My 3-month-old son is a little higher maintenance than my 2 ½-year old ever was.  All in all, I think we’re doing pretty well, though I listen with interest to other parents who warn that the roughest days still lie ahead of us and that the “promised land” won’t come until they’re about 4 and 6.

All of this has led me to rethink a subject I thought I knew inside and out: birth spacing.  In my work life, I am a high-risk obstetrician – in addition to seeing patients, I spend a part of my time doing research on birth outcomes like prematurity and pregnancy complications.  One of the areas I’ve been most interested in lately is how the amount of time a woman waits between pregnancies affects the outcomes of those pregnancies.  More and more evidence is mounting to suggest that there may be such thing as “too short” or “too long” between pregnancies.  

It turns out that the interval of time with the lowest risk of problems like early deliveries, stillbirths and small babies is around 18-24 months between the birth of one baby and the conception of the next pregnancy.  However, having talked to lots of new moms about this (and now as a mother of two myself) it always seems more natural to talk about how far apart in age your kids are – it’s awkward cocktail party talk to discuss when #2 was conceived.   

So, the oft-talked about ideal spacing of births two years apart is probably a tad short, though not by much. The problem with short intervals may have to do with not being able to replenish important micronutrients like folic acid, lost in the normal process of pregnancy, delivery and lactation.  It’s not as obvious why waiting longer periods of time might be associated with poorer outcomes, aside from the fact that women are older (which most studies already account for).

I’ve been singing the praises of the “ideal” interpregnancy interval from the mountaintop (or at least, from my office), advising postpartum families to think about waiting 1 ½ - 2 years before trying to conceive again.  And I took my own advice: I got pregnant almost exactly 18 months after my first delivery.  Yet, as I am now actually living it, I understand better than ever that no matter what the medical data say, no interval is perfect.  Had we waited longer, we might have given our older son more time to be our one and only, and might have saved him a little jealousy and angst.  Had we tried sooner, the boys would be closer in age and maybe would've had some advantages of that tight relationship.  We’d also be rid of the Diaper Genie that much faster, a milestone I look forward to with great anticipation.  

As with everything, there are pros and cons to any birth spacing strategy.  So, armed with my newfound respect for mothering more than one child, my advice to those contemplating pregnancy would be:

Have a plan! The Centers for Disease Control and Prevention recommend that all women of reproductive age have a “Reproductive Life Plan.” Sounds complicated, but it's really just a well-thought-out collection of ideas for one’s family: Do you want any/more kids?  How would you ideally like them spaced?  What steps will you take to make sure your goals are met?  Of course, not all of the plans we make will work out exactly as we intended; the RLP is meant to be a flexible roadmap that is updated over time.

Before you try to get pregnant (a first time or any time), make sure you are medically, emotionally, and financially ready.  If you’re able, see a health care provider for a preconception visit to make sure all the i’s are dotted and the t’s crossed – things like making sure your immunizations are up-to-date, any chronic medical issues are in check and that you’re taking care of any preventative health measures (like weight loss or oral hygiene).

Keep in mind that the lowest-risk time to conceive again after the birth of one baby is probably around 18-24 months later. But understand that this is not the right timing for everyone.  Some families may wish or need to wait much longer for a host of great reasons.  Plus, the information we have doesn’t take into account well the competing concern of getting older – for some women, waiting 18 months in between pregnancies is just not the right strategy to reach their ideal family structure.  For any questions about this, checking in with a health care provider is always a good idea.

No matter what your plans are, keep yourself as healthy as possible. Pursue a well-balanced diet, rich in those vital nutrients that will help to support you during a pregnancy and lactation.  I also recommend continuing to take some kind of multivitamin (prenatal or otherwise) with folic acid, both to protect against birth defects as well as to promote overall pregnancy and postpartum health.

Last, but not least, talk to your peeps!  Much as it’s great to involve your health care provider in your thought process, the people closest to you (partners, kids, extended family, close friends) are some of the most important sounding boards when it comes to figuring out the “best” time to have another baby, if that’s in your plan!

~Allison Bryant, MD, MPH

The author and her family.
As Allison mentions in her post, if you're thinking about getting pregnant, there are many things to think about; nutrition is an important one. For some ideas on eating more folate, try our Asparagus, Potato and Leek Hash, Mama Mujadarrah, Asparagus and Pea Soup, or some delicious avocado (in guacamole form or a salad).

How far apart in age are your kids? How about you and your siblings?


  1. Or at 11-12 months babies sleep a little better and you are more likely to have "alone time" with your parter?? :)

  2. Thanks, friend! Motherhood has made me smarter than anything else so far...

  3. It's hard when my *one* kid won't nap! Can't imagine also having to manage nursing/entertaining a baby, plus a non-napper...

  4. Oh, and my two are 23 months apart. I did a whole lot of crying during my first year as a mother of 2. And for the record, being pregnant with a toddler is not for amateurs! Things are truly much better now that they are 4 and 6. I don't know if I truly believe ideal spacing exists - it all depends on the family. Allie was right about one thing: make sure you are emotionally and financially ready for the 2nd because it is rare that siblingsnap at the same time!

  5. Wow - that Allie B was always the smart one, wasn't she? Seriously, great work, Allie!

  6. oh, and me and my older sister are 18 months apart but that's because my mother's Aunt Flo had yet to return and she thought she was safe. Bawhahahahah!

  7. I think it's because when your baby turns a year old, all of a sudden, you're like "what happened to my baby?! i need another one!" ha ha. 

  8. I never had, until Allison started doing research in the field. I think the second thing (pretty sure "YAY!" was the first) i said to her when I found out she was expecting #2 was, "Wait, Miss Birth Spacing, let me do my math to see if you waited long enough." Or something along those snarky lines.

  9. it's funny, i know quite a few people with the 21-month age difference (including me and Flan). Something magic about that number...

  10. My daughters are 21 months apart, which was a little closer than ideal for us. My OB said that since I had a c-section with my oldest, there should be at least 18 months between births, so I managed that! If I had to do it over again, I would've waited until my oldest was ready for preschool, for logistical reasons, mostly. I am relatively young (31), so I could wait a few years before having a third but that might be too much space for me. 

  11. (Great post, by the way. I hadn't considered the difference between conception spacing and birth spacing.)

  12. There is quite a lot of research data on this. There was public health campaign around three year spacing for sometime, and the World Health Organization says three to five years is best.

    This is good:
    This research update has come concise facts and figures.

  13. Thanks for sharing these informative links!

  14. Really nice atricle. This is very useful for me :)


Post a Comment

Popular Posts