Hi friends! Whenever I catch myself writing a way-too-long reply on a Substack note, it usually means I should take it to a post. This essay is a response to the idea that it’s not only fine but maybe even good to intentionally space children very closely. That view is currently being promoted by
, the famous avowed pronatalist! In his exact words “It’s Very Good And Cool That You Can Have Two Under Two.” As someone who’s worked with childbearing families for two decades, and lived through my own version of the parenting trenches, I can’t help but push back.In a fascinating essay called There is No Natural Parenting, he makes the argument that humans—well, not all humans, but specifically “terminally-online Substack-reading 21st century European-ancestry” people—have evolved to tolerate lactose, thus making the ability to breastfeed our young less essential to their survival because we can substitute cow’s milk at a fairly early age. If you follow this “evolved to do less breastfeeding” argument to its natural end, mothers will have shorter periods of lactational amenorrhea-related infertility, less nutritional demands on their bodies, and therefore more closely spaced pregnancies.
He doesn’t really comment on the implications for the 80% of people who aren’t white, who also have varying levels of lactose tolerance. But still, it was a fascinating read, and Stone isn’t the first to suggest that one of our species’ greatest strengths is dietary flexibility. It makes sense that this evolutionary advantage would apply to babies as much as adults. However—as far as I can tell—prolonged breastfeeding is far more related to maternal desire, effort and cultural normativity than any specific genetic profile. But what do I know? I’ve only worked with hundreds of breastfeeding women of all different races for 20 years. 🤷
Stone’s essay was a response to other authors, such as
who recently wrote about her own experience of intentionally having two children very closely spaced, and then realizing afterwards how challenging this arrangement was. I really appreciate her humility in sharing her story. Since then, one of the battles she’s taken on is “explaining the evolutionary science behind how unnatural it is to have two children under two, especially if you are home alone without much help.”Here’s her description of her own experience:
But from the moment I had two under two in my care, it was no longer possible to even pretend to carry on as before. My son was attending a local daycare, but he was constantly home with some kind of viral illness. He was insanely jealous of my daughter. The first time he saw me breastfeeding her, he melted into a pool of despair. I felt constantly pulled in two directions by my two children who constantly wanted me and only me. I was wracked with anxiety over the fact that no matter how hard I tried I could not give them both what they needed. All of us were constantly crying. My daughter was crying, because she wanted to be held. My son was crying because he wanted to be held. And I was crying because I could not hold them both (and maybe because I also wanted to be held).
Dang, I am crying after reading that. It makes my heart hurt.
Of course some families thrive with kids close in age. But my concern isn’t that it’s always disastrous—it’s that we’re glossing over very real risks and selling women a story that doesn’t serve them. There are common sense health reasons why having two under two isn’t a good idea.
While I don’t love to throw the words “natural” and “unnatural” around, here’s my argument: Having closely spaced pregnancies is not ideal. It is not good for maternal health and is not good for infant/child health. While I don’t want to catastrophize or say that people who find themselves pregnant with unplanned, closely spaced pregnancies are doomed, we should not write off this very significant risk factor.
In healthcare circles, we even have a high-risk pregnancy code for it: O09.89x, short-interval pregnancy (the x is 1, 2 or 3 depending on the trimester). Here’s a definition:
Short interval pregnancy is defined in the medical literature as an interpregnancy interval of less than 18 months between a live birth and the conception of the subsequent pregnancy. Some studies and guidelines further stratify short intervals, with intervals less than 6 months considered to confer the highest risk, and intervals of 6–11 months and 12–17 months also associated with increased risk of adverse maternal and perinatal outcomes.
And here are some of those adverse outcomes gathered from Open Evidence AI (references at the bottom if you’re interested):
Neonatal risks include:
• Preterm birth: Adjusted odds ratios (OR) for preterm birth at intervals <6 months range from 1.49 to 1.65 compared to 18 months.[2-4]
• Low birth weight (LBW): ORs for LBW are 1.33–1.65 for intervals <6 months.[2-4]
• Small for gestational age (SGA): ORs are 1.14–1.24 for intervals <6 months.[2-4]
• Neonatal mortality: ORs for early neonatal death and overall neonatal mortality are 1.78–1.91 for short intervals.[2]
• Congenital anomalies: Slightly increased risk (OR ~1.10).[3]
Maternal risks include:
• Maternal mortality or severe morbidity: For women ≥35 years, risk at 6 months is 0.62% vs 0.26% at 18 months (adjusted risk ratio [aRR] 2.39); for women 20–34 years, no significant increase.[5]
• Uterine rupture: Increased risk in women undergoing trial of labor after cesarean with intervals <18 months.[1]
• Gestational diabetes and obesity: Some evidence of increased risk for gestational diabetes and starting the next pregnancy obese.[6]
Magnitude of risk is greatest for intervals <6 months, with a dose-response relationship showing decreasing risk as interval lengthens toward 18–23 months.[4][7]
So were moms meant to care for multiple babies at the same time?
I work at a community health center where short-interval pregnancies are fairly common. This tends to occur more often in younger parents and those facing economic or educational disadvantages—factors that can make accessing contraception, childcare, and healthcare more challenging. I’m on my clinic’s quality improvement team, so I do a case review each month of all the low birth weight babies (<2500g, or 5lb8oz). I look for various risk factors and try to help our clinic come up with ways to better serve these patients. Guess what comes up a lot? Short-interval pregnancy!
I’ll never forget one case: I was attending a birth in December and felt a strange sense of déjà vu—then realized it was because I had caught the same mom’s first baby in January, just eleven months earlier. This tiny one came on the heels of a sibling that had been born prematurely. Pronatalists might see this as a success story—“more babies!” But for this mom, the exhaustion of back-to-back pregnancies with relatively high-needs babies was enough to make her swear she was “never having kids again,” and to start a highly effective birth control method. It makes me wonder: do closely spaced pregnancies really lead to more children overall, or fewer—because tired, depleted, and overwhelmed mothers end up working even harder to prevent future pregnancies? I think the jury’s still out.
I want to make a strong argument here that
is right. The arrangement of a mother having to care for two under two is not ideal. As I said, I don’t like to throw around the word “natural,” but it’s really clear that nature has not selected for moms to have multiple babies under their charge at once. Twin pregnancies are pretty rare in nature—occurring in only 1.3% of pregnancies—and also bring with them very increased neonatal and maternal morbidity. It seems entirely plausible that multiple gesatations were not selected for in our species because they are more likely to result in the death of the offspring. Of course, modern day obstetrics has stepped in and is now able to prevent a lot of these deaths. And twin pregnancies are (barring IVF) a fluke of nature, not something we can or should try to prevent. Closely spaced pregnancies, on the other hand, can be prevented through both lactational amenorrhea and modern birth control.How good is lactational amenorrhea at preventing pregnancy?
Meh. I’ll admit it’s not great. I wouldn’t necessarily recommend it to someone who really wants to prevent a pregnancy. But if someone is exclusively breastfeeding, it will probably buy them 6-9 months. Personally, I got 14, 10, and 10 months after each of my kids was born. They were big backs, so I am not saying that’s typical. But in my practice, it is almost never the breastfeeding moms that come back pregnant within a few months. Just sayin’.
Why close interval pregnancy makes me worry
This brings me to another story from my own practice. Recently, I came to work one morning and a coworker said, “Guess what? Myrtle is pregnant again!” For the sake of this story, Myrtle isn’t a real patient but a composite—she’s the patient we’ve all cared for over the years, the one who always seems to be pregnant, with barely any time between births. And it’s not that we don’t like Myrtle. We love Myrtle. She’s a lovely woman. But she scares the crap out of us!
Every time she’s pregnant, we carry a constant sense of dread, waiting for the other shoe to drop. We remember when her hemoglobin was 6.8 (severe anemia) during pregnancy but she kept no showing for her iron infusions at the hospital because she had no one to care for her toddler. We remember consulting with the OBs about whether it was safe to let her try for a vaginal birth after cesarean (VBAC) just 14 months after a prior C-section, hoping her uterus wouldn’t rupture, yet knowing another surgical birth so soon carried its own dangers. We remember when her water broke at 28 weeks and her baby spent months in the NICU. We remember when she developed severe postpartum preeclampsia but wouldn’t come back to the hospital for magnesium sulfate because she couldn’t find childcare. Oh sorry—did I already use the childcare example? That’s because it happens ALL THE TIME! Almost every day I have patients who simply cannot follow through with my pregnancy-related recommendations, or even come to their appointments, because they are saddled with the care of multiple other young children.
Will modern medicine save us?
I take issue with
implying that modern medicine can simply step in and take the place of the 72 mo pregnancy intervals that our evolutionary ancestors probably had. While I appreciate his trust in us healthcare professionals, this “throw caution to the wind” attitude frightens me (and TBH, it feels icky because he’s actually recommending this to women, not taking on these risks in any personal way). It’s the same way I felt about the suggestion that women should delay childbearing into their 40’s and use IVF to get pregnant despite the well-known risks. While we’re at it, let’s eat at McDonalds every night and smoke a pack of cigarettes. What are cardiac cath labs for, anyway? No worries—modern medicine has got our backs!Also—have you read the news about our healthcare system lately? Pediatric and maternity units are closing, Medicaid cuts are looming, insurance premiums are skyrocketing, anti-vaxxers are inventing their own immunization schedules for children, and funding for scientific research is shrinking. Unless you’re 65+ with access to nationalized healthcare, betting everything on “modern medicine” is a bit optimistic!
Coming down from my panic attack—yes, of course, we will do everything we can to help you if you have a short-interval pregnancy or any of the health complications that come with it! But help us help you by making good choices around your health. Yes, we know that accidents happen. 😉
Please, do what you want. Don’t mind me.
I’m not arguing that short-interval pregnancy is the worst thing that could happen in a family. I have this conversation often with moms facing unplanned, closely spaced pregnancies but also with those that have them intentionally. I’ve talked to women who struggled to conceive and said, “No thanks on birth control—if I get pregnant again right away, that would literally be the best thing that’s ever happened to me.” I’ve also known moms who found the right partner later in life and were racing against their biological clocks to have their desired number of children. There are absolutely circumstances where closely spaced children make sense. Also, risk is relative: what’s challenging or even dangerous in one person’s context may be manageable in another’s. General health and support systems definitely enter into the equation.
At the end of the day, people have to weigh the risks, consider their circumstances, and make the decisions that work best for their families. Short-interval pregnancy can be risky—but it is a risk people are entitled to take if it makes sense for them.
Maternal energy is finite.
I really enjoy following the discourse on parenting on Substack, but partly because I now get to do it from the safe vantage point of someone who doesn’t feel judged by every conclusion, since my kids are older (16, 13, and 10). And I honestly spend very little time wondering if they’d have turned out differently if I’d just done xyz differently, because I quite like who they are already! I just know that when they were little, it was damn hard—and that was with 3 year spacing.
What worries me more than any single parenting choice is the broader “mommy martyr” current—the assumption that maternal energy has no ceiling. The expectation isn’t just daily care; it’s that a mother should give up her own interests, hobbies and passions to serve the needs of her kids 100% of the time. I just see that not going well for women in a lot of circumstances, both as a midwife and as a friend to other moms. Every parent has a finite amount of physical, emotional, and mental energy to give. We all have to try to spend it wisely. ✌️
REFERENCES ON SHORT-INTERVAL PREGNANCIES
1.Obstetric Care Consensus No. 8: Interpregnancy Care. Obstetrics and Gynecology. 2019;133(1):e51-e72. doi:10.1097/AOG.0000000000003025. Practice Guideline
2. Effects of Short Inter-Pregnancy/Birth Interval on Adverse Perinatal Outcomes in Asia-Pacific Region: A Systematic Review and Meta-Analysis. Hassen TA, Harris ML, Shifti DM, et al. PloS One. 2024;19(7):e0307942. doi:10.1371/journal.pone.0307942.
3. Short Interpregnancy Interval Can Lead to Adverse Pregnancy Outcomes: A Meta-Analysis. Wang Y, Zeng C, Chen Y, et al. Frontiers in Medicine. 2022;9:922053. doi:10.3389/fmed.2022.922053.
4. Association of Interpregnancy Interval With Adverse Birth Outcomes. Xu T, Miao H, Chen Y, et al. JAMA Network Open. 2022;5(6):e2216658. doi:10.1001/jamanetworkopen.2022.16658. Leading Journal
5. Association of Short Interpregnancy Interval With Pregnancy Outcomes According to Maternal Age. Schummers L, Hutcheon JA, Hernandez-Diaz S, et al. JAMA Internal Medicine. 2018;178(12):1661-1670. doi:10.1001/jamainternmed.2018.4696.
6.Interpregnancy Interval and Adverse Pregnancy Outcomes: An Analysis of Successive Pregnancies. Hanley GE, Hutcheon JA, Kinniburgh BA, Lee L.Obstetrics and Gynecology. 2017;129(3):408-415. doi:10.1097/AOG.0000000000001891.
7.Birth Spacing and Risk of Adverse Pregnancy and Birth Outcomes: A Systematic Review and Dose-Response Meta-Analysis. Ni W, Gao X, Su X, et al. Acta Obstetricia Et Gynecologica Scandinavica. 2023;102(12):1618-1633. doi:10.1111/aogs.14648.
I mostly enthusiastically agree with this, as a mom of 2, but if you will permit me to go on a tangent:
I want to point out that the “no childcare” thing is an artificial problem. If clinicians did home visits - like most doctors used to, and like homebirth midwives do - this would not be a barrier to care.
Like: these pregnant women did not erupt a barrier to their own care. They are not “lacking” in childcare. The clinician is “lacking” in the will and ability to provide an appropriate, patient-centered care model that improves outcomes and has high feasibility and acceptability. Yes, I understand that the current model maximizes profit and maximizes convenience, but it does not serve the client.
As someone who has skipped several prenatals and a postpartum visit and had a VBAC (I skipped mostly due to transportation/work/childcare issues): I have to say, I never regretted it. I went into labor shortly after I skipped my 38w appointment because I’d had pinkeye and didn’t want to leave the house. I was feeling SO relaxed and peaceful, precisely when the surveillance picks up and the pressure to dilate switches on.
For these slightly higher-risk women (I was stage 1 hypertension, had a scar, family history of pre-e and diabetes, overweight) prenatals function as a kind of nocebo effect. You leave feeling really crappy about yourself and just genuinely discouraged. You get yelled at about your stats. You aren’t treated as a whole person. I saw a CNM/OB team and actually the OB was nicer to me, which was a surprise, but my sense was that they couldn’t help themselves: if a pathology existed, by GOD they were going to find it, they were going to exhaust every measure to find the pathologies in the haystack, and that was what they honestly believed constituted “care.”
I have mixed feelings about this essay. The risks are real, but many people don’t see the risks or exhaustion as a reason to avoid a pregnancy. It just feels like yet another medical professional being critical of our life choices and attempting to scare us.
I know that is not where your essay is coming from, but it’s been my experience. Most of my children have been born 2-3 years apart. I am currently pregnant with number 8. We exclusively breastfeed and co-op sleep (both usually are needed to keep fertility away) for the first year of the baby’s life, but this is not normal for the U. S. It has allowed us to have decent gaps between children.
I feel like what might help women( and men for that matter) to space children more is rather than talk exclusively about risks, is the conversation about holistic health. For example, how long it actually takes to rebuild vitamin levels in your body after pregnancy (4 years!), how are you planning on caring for your other children because exhaustion is real, what about your mental and physical health, how this can take a toll on the family. All this can help a woman realize that if she wants another child, she needs to be healthy for the best outcomes for herself, baby, and family.
Most of us having large families tend to do it because of religious convictions. Children are gifts, tough but worth it. And we don’t regret bringing a beautiful and unique person into the world. Until the medical profession can recognize this as part of the conversation, the risks seem paltry.