Claim: Climate Change Causes Premature Births

Three month old infant lying on stomach
Three month old infant lying on stomach. By Tognopop (Own work) [Public domain], via Wikimedia Commons

Guest essay by Eric Worrall

A new study suggests climate change causes more women to go into premature labor, though the effect is diminished in warmer climates.

How Rising Temperatures Due to Climate Change are Shortening Pregnancies

BY JEFFREY KLUGER  11:00 AM EST

To study this effect, Alan Barreca, an associate professor at UCLA’s Institute of Environmental Sustainability, and economist Jessamyn Schaller of Claremont McKenna College, analyzed daily temperature and county-by-county birth rates across the U.S. in a two-decade window from 1969 to 1988. That is an admittedly old dataset, but the researchers had little choice.

“In 1989, the vital statistics system started to be more cautious about information it allowed out publicly in order to make it hard to identify individuals precisely by place or date of birth,” says Barreca. “They even began masking some counties. So 1969 to 1988 gave us the most thorough information.”

In that dataset, the researchers found that on days when temperatures reached or exceeded 32.2ºC (90ºF), the birth rate per 100,000 women increased by 0.97, compared to dates in which the temperature was between 16-21º C (60-70º F). There was a smaller, but still significant, bump of 0.57 additional births per 100,000 women on days that were hot but not quite as sweltering, ranging from 26.7-32.2º C (80-90º F).

“There may even be a third cause,” Barreca says, “which is loss of sleep. Minimum temperature on a hot day occurs at night, but it can still be hot enough to disrupt sleep, and that might be an important avenue to early birth.”

The effect of heat on pregnancy was less pronounced in hot-weather regions like the desert southwest and the deep south, probably because expectant mothers who live in these parts of the country have acclimated to high temperatures. Income makes a difference as well: greater wealth means a greater likelihood of air conditioning in the home, mitigating the pregnancy-shortening effect of temperature. And since, in the U.S., income often breaks down along racial lines, the study found that African-American mothers are somewhat more likely to experience temperature-related early births than white mothers.

Read more: https://time.com/5740394/climate-change-early-births/

The abstract of the study;

The impact of high ambient temperatures on delivery timing and gestational lengths

Alan Barreca & Jessamyn Schaller 

Evidence suggests that heat exposure increases delivery risk for pregnant women. Acceleration of childbirth leads to shorter gestation, which has been linked to later health and cognitive outcomes. However, estimates of the aggregate gestational losses resulting from hot weather are lacking in the literature. Here, we use estimated shifts in daily county birth rates to quantify the gestational losses associated with heat in the United States from 1969 to 1988. We find that extreme heat causes an increase in deliveries on the day of exposure and on the following day and show that the additional births were accelerated by up to two weeks. We estimate that an average of 25,000 infants per year were born earlier as a result of heat exposure, with a total loss of more than 150,000 gestational days annually. Absent adaptation, climate projections suggest additional losses of 250,000 days of gestation per year by the end of the century.

Read more: https://www.nature.com/articles/s41558-019-0632-4

Sadly the full study is paywalled. But I’m glad the authors pointed out that air conditioning makes a difference.

The solution to this problem, if it exists, is obviously more fossil fuel; cheap energy, a stronger economy with more opportunities for poor people, and greater availability of air-conditioning.

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51 thoughts on “Claim: Climate Change Causes Premature Births

      • What does it matter that pregnancies are shorter? Does it hurt the infants’ health? NO mention of that. Are there an increased rate of premies and expensive and life-threatening lack of development. As women are homeotherms, it is unlikely that the actual pregnancy is affected. Rather there might be other mitigating factors that simulate a woman to deliver her child.

        Wait, wait. We were cooling during those two decades. Cooling stopped in 1988-9. So, their conclusions are completely bogus.

        • Charles: My thought exactly. Once babies pass a certain level of development (and it’s much earlier than your OB/GYN is telling you), they are fine. Anecdotally, based on people I have known, it’s somewhere just past 7 months.

          Without a study on the actual outcomes, this study is another yawner.

          • They are just selling their premature baby healthcare services that serve no purpose for most “premature” babies – even some “extreme” (not so) premature.

    • What does it matter that pregnancies are shorter? Does it hurt the infants’ health? NO mention of that. Are there an increased rate of premies and expensive and life-threatening lack of development. As women are homeotherms, it is unlikely that the actual pregnancy is affected. Rather there might be other mitigating factors that simulate a woman to deliver her child.

  1. Define premature, in the U.K. it’s any child born before the 34th week and probably need special care/intensive care, after this they are pre term up to 40 weeks and may need special care, but only if they weigh less than 2.5kg. Also that children born at 24 weeks have survived.
    The labour process is initiated by the baby in utero not the mother.
    There are many reasons why a prem baby is born and, as far as I am aware, no one is exactly sure why.

  2. If the statistics mean anything its that on warm er days more babies who have not yet reached full term are born.

    So where is the connection with a major variation in the pattern of the weather. ?

    MJE VK5ELL

    • “So where is the connection with a major variation in the pattern of the weather. ?”

      There is no major variation in the weather, so there is no connection between human-caused climate change and more births at higher temperatures. There may be more births during higher temperatures, but the temperatures are not connected to human-caused climate change because there is no evidence showing humans are causing the climate to change. It’s pure speculation and the temperatures are currently cooling not warming. Temperatures are down about 0.4C from 2016.

      Alarmist are assuming temperatures are continually rising and human-caused climate change is real. They are wrong on the first count, all you have to do is look at a legitimate global temperature chart (UAH), and they have no evidence that humans are causing changes in the Earth’s climate.

    • Yes, they also ought to just consider the temperature range over the course of the pregnancy only. Over nine months this will often be down not up.

      Of course this is all irrelevant because I’ll bet dimes for dollars that their data set is not large enough to substantiate significant statistical claims and rule out the godsquillian likely confounding factors.

    • So, OK, what was going on 9 months ago? Lessee, born in July, conceived in October, August/November…
      Looks like in the dark and dreary months, folks are making their own entertainment.

  3. The question is “are the births actually premature?” perhaps conception is most likely to occur in autumn leading to summer births. This could be a last vestige of a primitive survival strategy to have children when weather and food supplies are good. Alternatively cold weather might delay birth, again a primitive response to try to give birth in good weather.

    In any event they admit the difference is smaller in hot climates, so if the climate warms the effect will reduce.

      • Excellent question. Too bad the study is not free access to confirm if they explored this. Would have also liked to see if they looked for the echo, in that if indeed hot days caused early birth you would expect a comparable reduction in births after a heat wave.

  4. If we get the promised global warming we will surely adapt to it in the way women apparently do in warmer zones, the effect appears to be relative. But anyway, this seems to be confusing correlation with causation since the article admits they don’t know how the effect works.

    • What’s next? Men grow beards, women grow longer hair, they all wear hunting camo and boots, carry hunting gear and disappear into wilderness areas?

    • “Is there nothing global warming/climate change/climate emergency* can’t do?”

      Human-caused climate change is GOLD for science. All a scientist has to do to get his money grant is to tie his particular area of expertise to human-caused climate change. And so they do, and they blame everything under the sun on something that has never been shown to exist. The beauty of it for most scientists is they don’t have to prove human-caused climate change exists, they can just assume it does, based on the IPCC, and go about their business.

      All their science is based on erroneous assumptions. They shouldn’t build their house on a foundation of sand because one day the house will collapse.

      • Now, now, Tom – climate change does exist. It is called glacial periods interspersed with warm periods, during which hominids flourish and advance because better hunting conditions/industry is invented (you name it!) and those things only happen during the warm periods.

        I mean, after all, if the glaciers hadn’t started melting back 20,000+/- years ago (depending on which continent you’re talking about, we might not have iPods and Tesla cars to look at now. We wouldn’t have people squawking about had bad oil-related stuff is, even when they’re wearing it, for Pete’s sake!

  5. “It’s this global warming I tell ya, It’s responsible for everything”.
    Can’t be too long now before global warming, sorry, my mistake, that should read ” the climate crisis caused by man made CO2 production, which is increasing the potential of the temperature to rise in the atmosphere crisis”, can’t be too long, before it is presented as the cause of the obesity epidemic.
    This is the logic. All that extra CO2 causes the grass lands to grow well. This gives rise to additional grazing animals available for human consumption. More beef, equals more calories, equals more obesity.
    So it is obvious isn’t it. If we want to stop obesity then we must stop using fossil fuels….

  6. Hey, I’ve got a solution. Let’s make electricity prices “skyrocket” by using Greentard energy policies as justification. That way not just the low income families can’t afford A/C but most of the middle class too.

  7. Wait a minute, those impatient doctors may be inducing labor on warm days, with bucopotosin (sp?) go get a ready-to-deliver event over with and then go join their friends on the golf course, because, after all, the report says it is a warm day. Wait another minute, this report is about one event in 100,000? Never mind.

    • 1988 was about the time that women started having babies later. The death rate of babies during delivery is high for the combination of older mother and late baby. Practice now is to induce close to the due date for all women (except for the rigidly natural crowd). Recently somewhere in Scandinavia they canned a randomised trial of letting women go late after 6 babies died. All this changed very rapidly, because my first was allowed to go 2 weeks late in 1979, and my second was checked for placental integrity 1 week late, while my third was scheduled for induction on his due date.

      This kind of practice will take all the 42-weekers out. So the stats for the period will show a clear trend that is from fewer late babies.

      Women’s groups have blamed OB’s for trying to induce and having to resort to cesearian when it does not work. It will only work if the baby is ready to come. However, by the time women have carried an infant for 37 weeks, I have not met one who did not desperately want to be free of it, and many ask the OB to induce.

      1979 was a brutally hot summer in Quebec. It sure did not cause that baby to come early.

  8. So climate change causes premature births but not in warming climates. The study doesn’t make internal sense. Seriously?

  9. A decade ago we had Sherrington’s Postulate that increased CO2 in the air caused excess tooth growth in those born since 2000 or so. Nobody has shown this to be wrong. Geoff S

  10. So they went and got data from 20 years ago because no one thinks it important enough to keep current records? This must be one heck of a critical problem.

    Next problem: Does climate change cause the toast to land butter side down?

    • Now be fair. In the text it was clearly stated “…in a two-decade window from 1969 to 1988. That is an admittedly old dataset, but the researchers had little choice.

      “In 1989, the vital statistics system started to be more cautious about information it allowed out publicly in order to make it hard to identify individuals precisely by place or date of birth,” says Barreca. “They even began masking some counties. So 1969 to 1988 gave us the most thorough information.”

    • “Does climate change cause the toast to land butter side down”?
      Now listen up Clarky,
      1. The more sophisticated punters wait for the toast to land on the worktop before buttering it.
      2. How come you are still allowed to own pop up toasters down there in Oz? Most of us are only admitting to such energy extravagant in private, to well trusted realists in case the energy police get to hear about it here in Greta EU Land.

  11. I spent three years as a postdoc studying preterm births. This is a garbage study, what we technically call a “spurious association”. First, to get their significant p value, they declare anything under forty weeks as preterm. That’s total garbage since normal gestation is 38-42 weeks and even 37 weeks is considered normal simply because women don’t always know exactly when they got pregnant. By setting the bar at 40 weeks they artificially put half the population into the abnormal category making it easy to get a statistically significant p value. We evolved in warmer climates than most places we actually live in. Women tend to give birth when conditions are right (give or take a few days) not because of the calendar they got at their doctors’ office. That’s why more babies are born predawn than during the day (excluding C sections). Nice warm days for someone in the north is better for birthing because newborns do better in warmer temperatures. This is why we put newborns under baby warming lights and incubators. Normal physiology kicks in and senses this is a good time to drop a baby precisely BECAUSE it is warm. However this article was published in Nature Climate Change and that alone proves it is a garbage article. They got laughed out of any real obstetric journal and could only get this spurious association published by a garbage journal pushing a scam agenda.

    • That still does not explain why my sister interrupted a Christmas Eve party in Chicago and sent my mother to the hospital on 12/24, nor does it explain why I was born in the first week of February. Cold periods, all.

      In fact, that study is so ridiculous that it does not explain why so many babies have been born when the weather is still cold enough to make you sit up and take notice.

  12. The explanation of the oddity that all climate impacts are bad, that all bad things are climate impacts, and that in the science of climate impacts there is no good impact and no attribution failure in the face of large uncertainties is that climate science is not unbiased objective scientific inquiry but agenda driven to provide the rationale needed for a pre-determined climate action agenda. The climate action agenda is not made to fit the science but rather it is the science that has to fit the climate action agenda.

  13. I was thinking the same thing, although I thought premature births, horse fat, and invasive cancer caused climate change. These things have been happening before our century and I think they lead climate change by more than 30 years.

  14. “We estimate that…..”
    Sure, make a statistical observation of dubious importance and then create your hypothesis after the fact without any direct observational data because that’s how academic careers are made. It isn’t however how real science is done. Back of the class for you.

  15. I don’t see a MD by either name…nor do I see anything about mathematics degrees.
    % means per hundred, but the article list births per 100,00. Now I’m a little rusty in the math department but I think it should be “the birth rate per 100,000 women increased by 0.97 (0.00097), compared to dates in which the temperature was between 16-21º C (60-70º F). There was a smaller, but still significant, bump of 0.57 (0.00057) additional births per 100,000
    How “premature” were the children?
    Want to get a good related project? What was the premature birth rate among women that lived in AZ while their husbands worked on the Hoover Dam (Boulder Dam now)?

  16. “The effect of heat on pregnancy was less pronounced in hot-weather regions like the desert southwest and the deep south, probably because expectant mothers who live in these parts of the country have acclimated to high temperatures.”

    So what’s the problem then? If global warming ever does show up, getting acclimated to higher temperatures seems to be the solution to the problem. We don’t need to spend trillions in a fruitless effort to stop climate change. We just need to learn how to adapt to it.

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