Born before 22 weeks, ‘most premature’ baby is now thriving

Courtney Stensrud and her husband call their fun-loving, spunky daughter a miracle.

The now 3-year-old girl was born at just 21 weeks and four days gestation. “She may be the most premature known survivor to date,” according to a case report about her birth published in the journal Pediatrics last week.

In the United States, most pediatrics and obstetrics societies agree that 22 weeks of gestation is the lower threshold of viability, and many doctors recommend against assessing for viability or resuscitating babies born younger than 22 weeks due to a low chance of survival. Full-term babies are born at 39 through 40 weeks.

Before a medical emergency led to the early birth of her daughter in 2014, while still in the antepartum room at Methodist Children’s Hospital in San Antonio, Texas, Stensrud said that she searched online for any other mothers who gave birth at 21 weeks.

“There were stories of 22-weekers, 23-weekers, but nothing about 21-weekers. So I knew that there was little to no survival or viability at 21 weeks,” said the stay-at-home mom, now 35.

Just after Stensrud gave birth, Dr. Kaashif Ahmad, a MEDNAX-affiliated neonatologist at the hospital and lead author of the case report, counseled her about the baby’s extremely low chances of survival and initially counseled against resuscitating the baby.

Stensrud listened as she held her 15-ounce girl in her arms, with the umbilical cord still attached, she said.

“Although I was listening to him, I just felt something inside of me say, ‘Just have hope and have faith.’ It didn’t matter to me that she was 21 weeks and four days. I didn’t care,” Stensrud said.

“As he was talking to me, I just said, ‘Will you try?’ And he said he would, and three years later, we have our little miracle baby,” Stensrud said.

“I don’t tell her story a lot, but when I do, people are amazed,” she said. “If there’s another woman in antepartum that is searching Google, they can find this story and they can find a little bit of hope and a little bit of faith.”

Stensrud requested that CNN not publish her daughter’s name or current photos to respect her family’s privacy.

Ahmad pointed out that Stensrud’s daughter was one case, and more research needs to be done on preterm births lower than 22 weeks.

“We have to be very cautious about generalizing one good outcome to a larger population,” Ahmad said.

“It is very possible that there have been many 21-week babies resuscitated in other places that did not have positive outcomes, and for that reason, we haven’t heard about them,” he said. “We reported this case because after this resuscitation she did well, but it may be possible that this is just an extraordinary case and that we shouldn’t expect the same from other babies. We have to learn more before we can make any conclusions.”

‘She very slowly changed colors from blue to pink’

Around the world, an estimated 15 million babies are born too early — before 37 weeks gestation — every year, according to the World Health Organization.

Last year, preterm birth affected about one of every 10 infants born in the United States, according to the Centers for Disease Control and Prevention.

There has been an increase in the prevalence of preterm births in the United States, with an additional 8,000 babies being born prematurely last year due to a rise in the preterm birth rate between 2015 and 2016, according to a report released Wednesday from the nonprofit organization March of Dimes.

Pediatric and obstetric professional society guidelines are routinely updated to answer that challenging question of when resuscitating a preterm baby should be recommended or not.

The question also remains imperative for neonatologists who care for infants’ medical problems. The answer to such a question remains tangled in concerns of ethics, health care costs and lifelong health outcomes for an infant.

Now, Ahmad hopes this latest case can help guide the pursuit for the right answer, he said.

In the new case report, Ahmad and his colleagues describe how they resuscitated Stensrud’s daughter and how she needed prolonged care in the neonatal intensive care unit, known as the NICU. She wasn’t discharged from the hospital until 126 days after being born.

Stensrud went into early labor due to a premature rupture of membranes and a common infection of the placental membrane called chorioamnionitis, according to the report.

When Ahmad and his colleagues entered Stensrud’s labor and delivery room, they were not expecting to resuscitate the preterm baby, he said.

“But when the mother asked that we do everything for her daughter, despite having no reason to believe the baby would survive, I just made the decision to proceed with a vigorous resuscitation,” Ahmad said.

“So we placed her under an overhead warmer, we listened, and we heard her heart rate, which we were not necessarily expecting,” he said. “We immediately placed a breathing tube in her airway. We started giving her oxygen, and really pretty quickly, her heart rate began to rise. She very slowly changed colors from blue to pink, and she actually began to move and began to start breathing within a few minutes.”

By 2 years old, even though she was smaller in size than her peers, Stensrud’s daughter achieved scores that were average for a child around 20 months on Bayley III tests, according to the report. The tests, intended to measure child development up to age 3, assessed her cognitive, motor and language abilities.

“For this little girl, we say that her fine motor was age equivalent of 20 months,” Ahmad said.

“That is what we would expect the average 20-month baby to do,” he said. “She was at that time 24 months, but as we noted in the case, if you take into account how many weeks early she was, she was actually about 20 months, corrected.”

She did not develop any auditory or visual impairments or cerebral palsy, according to the report, and she now attends preschool.

“If you didn’t know that she was so preemie, you would think she’s a normal 3-year-old,” Stensrud said. “In her school, she is keeping up with all the other 3-year-olds. She loves playing with other kids. She loves everything I think a normal 3-year-old likes. She loves her baby dolls, she loves books, and she loves make-believe. She loves anything and everything her (older) brother is doing.”

‘The majority of infants born this early do not survive’

Though this baby girl’s case appears to be “exceptional,” there should be caution in assessing her outcome and even her true gestational age, said Dr. Noelle Younge, assistant professor of pediatrics at Duke University School of Medicine, who was not involved in the case report.

“Except in the case of assisted reproductive technology, there is always uncertainty about gestational age dating,” Younge said.

“First-trimester ultrasounds are generally thought to be accurate within five to seven days, so it is possible the infant may have been 22 weeks of gestation at birth,” she said. “As neonatal and obstetric care improve over time and a greater number of infants are actively treated at 22 weeks of gestation, there are likely to be more cases of infants who survive with favorable outcomes, but unfortunately, the majority of infants born this early do not survive.”

Overall, there has been an increase in survival rates for preterm babies, according to a recent study led by Younge.

The percentage of infants born at 22 to 24 weeks’ gestation who survived climbed from 30% around 2000 to 36% around 2011 across the United States, according to the study published in the New England Journal of Medicine in February.

The study involved data from the National Institute of Child Health and Human Development. The researchers assessed 4,274 births at 22 to 24 weeks of gestation in centers within the institute’s Neonatal Research Network.

The researchers found not only that survival rates increased between 2000 and 2011 but that the percentage of infants who survived without neurodevelopmental problems increased from 16% to 20%.

“However, rates of poor outcomes remain high,” Younge said. “Continued research into the causes, preventive measures and outcomes of periviable birth is critical. We need to continue to develop ways to improve outcomes for infants born extremely preterm.”

One turning point in understanding the medical problems and survival of preterm infants came in 1963, Ahmad noted.

That year, President John F. Kennedy and first lady Jacqueline Kennedy “had a son named Patrick who was born at 34 weeks and had a breathing complication of prematurity that, for us, would be a very easy routine to take care of,” Ahmad said.

“At that time just over 50 years ago, the technology and medicines available were not sufficient to save him, and he passed away within a matter of days,” he said. “Since that time, we’ve had sustained improvements in care that have pushed the boundaries of how premature a baby can be born and not only survive but have a positive developmental outcome.”

For now, Stensrud said that she hopes her baby girl’s case inspires the world.

She didn’t agree to tell her family’s story for herself or her daughter, she said, but “for those other parents out there.”

“From the moment she entered this world, she’s just always wanted to live,” Stensrud said of her daughter. “Now, she lives life.”

There are health-tracking wearables for babies, too

In their Atlanta home, 6-month-old Avery giggled and rolled on his piano mat, kicking his tiny feet into the air, while his mother, Crystal King, quietly checked his temperature on her cell phone.

Using her tablet, she could also monitor his breathing, body position, skin temperature and sleeping schedule, and an app notified her that it was time for Avery’s next bottle feeding.

“Avery eats like every three hours,” she said. “Having that built into an app is kind of cool, because it allows you to keep track.”

For CNN, King has been testing new and emerging health-monitoring technologies designed for babies, including a smart pacifier, which Avery would spit out, and a biometric-tracking onesie, which Avery hardly noticed he was wearing while he played on his mat, she said.

There are hundreds of high-tech gadgets on the market that promise to help new parents closely monitor their babies’ health and well-being. Often, they are no different than the Fitbits or Apple watches that adults wear, said Dr. Jennifer Shu, pediatrician at Children’s Medical Group in Atlanta.

“As far as wearable monitors for babies, that tends to be a little bit newer, and that may be some kind of monitor that has technology that’s paired up with a base station that then transmits information to a parent’s phone app,” Shu said.

“I recommend parents to follow their common sense. If it looks like something that could be safe that you want to try, then maybe talk it over with your pediatrician to see if they have any concerns,” she said. “But if it’s something that looks like it could be uncomfortable or hard to use, you may want to steer away from it.”

Wearables for wee ones

Can the information that these nursery technologies provide really be beneficial, or could they just be causing new parents to excessively worry?

King thinks smart thermometers and wearables could be useful to new parents, who could customize the amount of notifications they receive from a baby-monitoring app or technology in order to minimize feeling overwhelmed.

Technologies now available can help parents casually monitor a baby’s heart rate, temperature, feedings and sleep cycle, but experts warn against using them for valuable medical information or diagnoses.

For instance, a pacifier thermometer can be a convenient way to casually check your baby’s temperature at home, but for a medical emergency or when your child is sick, talk to your pediatrician about what’s recommended.

“It could alert a parent that the pacifier temperature is a little elevated (and) that they may want to recheck it using a rectal thermometer or a temporal artery thermometer,” Shu said.

“One important thing to keep in mind is that fever in a baby younger than about 2 to 3 months of age is always something to take very seriously, and that’s because fever in a very young infant can be a sign of a very significant infection that can spread through the body very quickly,” she said. “It’s something that you definitely want to talk to your pediatrician about right away.”

Additionally, the Food and Drug Administration has not cleared or approved any baby technologies or products as being able to prevent or reduce the risk of sudden infant death syndrome, known as SIDS. Some retail baby products have been marketed with false claims that they do, according to the FDA.

An opinion published in the medical journal JAMA in January even noted that “there is no evidence that consumer infant physiologic monitors are life-saving, and there is potential harm if parents choose to use them,” such as due to overdiagnosis by using consumer monitors.

On the other hand, it could be useful for tech-savvy parents to share the data from their smart thermometers or wearable devices with their pediatricians.

“In this new era of apps and tracking data, all this technology could be helpful, just as it’s helpful when a breastfeeding mom, for instance, shows me how well her baby’s been feeding,” Shu said.

“I take that information and put that together with how the baby looks in their examination,” she said. “But it’s not completely necessary, because we do look at the full big picture.”

King could see high-tech gadgets providing peace of mind at a time when parents already might have concerns about their child’s health, she said. For instance, Avery was born prematurely.

Parents of premature babies often need to be extra vigilant about infants’ feeding and sleep schedules.

Most premature babies have eight to 10 feedings a day, according to the American Academy of Family Physicians, and maintaining a regular feeding schedule can be stressful for a concerned parent.

There appear to be dozens of wearables for babies, such as wristbands that track heart rate, smart socks that track oxygen levels and a baby monitor button that snaps onto clothes. Those types of wearables for babies can set parents back a few hundred dollars.

As for smart thermometers, there are many brands in pacifier form, such as Vick’s or Blue Maestro’s Pacif-i, which connects to a smartphone. Smart thermometers can start around $20 and go up from there.

For parents considering investing in such technologies, Shu said they should be aware of potential safety hazards.

“Safety hazards could be things like getting entangled from wires, for example, if there are wires or having something that is soft or a choking hazard or any kind of suffocation hazard that might be in a crib or bassinet with a baby,” Shu said.

“We really don’t recommend that people depend on technology to take the place of common sense, and that means things like placing your baby on their back to go to sleep and having a bare crib. You don’t want anything soft or fluffy in the crib with the baby, because those kinds of things can suffocate and cause problems like SIDS,” she said. “Remember that products you buy are not a substitute for good adult supervision.”

It turns out that in the future, parents could use drones to supervise their children.

Could drones replace baby monitors?

A team of scientists from the University of South Australia recently designed and tested a drone that uses remote-sensing imaging systems to detect heart and respiratory rates in humans.

The researchers tested the drone on 15 healthy volunteers, including two children, 3 and 5 years old, said Javaan Chahl, a professor in the University of South Australia’s School of Engineering and a co-author of the study.

The researchers found that the drone achieved robust and accurate readings from the volunteers. The findings were published in the journal Biomedical Engineering OnLine in August.

“In other studies, we are exploring the idea of using this technique for infants. To date, we have captured data from quite a few infants, but all were in cots in their homes,” Chahl said.

“I would not be surprised if drones are eventually used to monitor many situations. They have an advantage of mobility that no ground robot can match, although their endurance is currently a bit limited,” he said. “As they become more intelligent, I expect that they will start to understand who and what they are looking at. For example, ‘Jasmine is skipping’ or even ‘Jimmy and Jia are chasing Anand.’ “

However, Chahl added that drones may not be absolutely necessary to use in the home, “since many people are already monitoring babies using cameras.”

Study ties pesticides in food to reduced fertility in women

Fruits and vegetables are an essential part of a healthy pregnancy diet, providing vitamins and fiber. Yet some might also come with pesticide residues.

Among women undergoing infertility treatment in the United States, consuming more fruits and vegetables with high amounts of pesticide residue was associated with a lower chance of pregnancy and a higher risk of pregnancy loss, according to a study published in the journal JAMA Internal Medicine on Monday.

Pesticides are pest-killing substances often applied to fruits and vegetables to help protect them — and us — against harmful mold, fungi, rodents, weeds and insects. There has been growing concern that exposure to pesticides can be tied to certain acute and chronic human health concerns.

“Most Americans are exposed to pesticides daily by consuming conventionally grown fruits and vegetables,” said Dr. Yu-Han Chiu, a research fellow in the department of nutrition at the Harvard T.H. Chan School of Public Health and first author of the study.

“There have been concerns for some time that exposure to low doses of pesticides through diet, such as those that we observed in this study, may have adverse health effects, especially in susceptible populations such as pregnant women and their fetus, and on children,” she said. “Our study provides evidence that this concern is not unwarranted.”

Yet the findings should be digested with caution, said Janet Collins, executive vice president of science and regulatory affairs for CropLife International, a trade association representing the manufacturers of pesticides. Collins was not involved in the study.

“The JAMA research publication does not show a direct link between pesticide residue intake and pregnancy outcome, as the authors state. This is a hypothesis generating study, and as the authors recommend, we agree that before a definitive outcome can be established the issues require further study,” she said in an emailed statement.

How harmful are pesticide residues?

The study involved 325 women between 18 and 45 who were undergoing infertility treatment with assisted reproductive technology at the Massachusetts General Hospital, the researchers said.

The women completed a diet assessment questionnaire and had their height, weight and overall health measured, while the researchers accounted for confounding factors that could influence the study results, including their intake of supplements and residential history.

The researchers analyzed each woman’s pesticide exposure by determining whether the fruits and vegetables she consumed had high or low levels of pesticide residues, based on reports from the US Department of Agriculture’s Pesticide Data Program, which monitors the presence of pesticides in foods sold throughout the United States.

Some fruits and vegetables with a low amount of pesticide residue include avocados, onions, dried plums or prunes, corn and orange juice. Those with a high amount include fresh plums, peaches, strawberries, spinach and peppers.

The researchers found that, compared with women who ate less than one daily serving of high-pesticide-residue fruits and vegetables, those who ate 2.3 servings or more had 18% lower probability of getting pregnant and 26% lower probability of giving birth to a live baby.

Consuming fruits and vegetables with a high amount of pesticide residue was positively associated with the probability of losing a pregnancy, the researchers found.

However, consuming low-pesticide-residue fruits and vegetables in lieu of high-pesticide-residue foods was associated with higher odds of pregnancy and giving birth, the researchers found.

“Although we did find that intake of high-pesticide-residue fruits and vegetables were associated to lower reproductive success, intake of low-pesticide-residue fruits and vegetables had the opposite association,” Chiu said.

“A reasonable choice based on these findings is to consume low-pesticide-residue fruits and vegetables instead of high-pesticide-residue ones. Another option is to go organic for the fruits and vegetables known to contain high pesticide residues,” she said. “It is very important to keep in mind that, as far as we are aware, this is the first time that this association is reported, so it is extremely important that our findings are replicated in other studies.”

However, purchasing organic fruits and vegetables can be costly, said Irva Hertz-Picciotto, a professor and director of the Environmental Health Sciences Center at the University of California, Davis, who was not involved in the study.

“This is more difficult for those already vulnerable due to their socioeconomic circumstances. Avoiding pesticides becomes an ‘environmental justice’ issue, making it all the more important to reduce use of pesticides throughout agriculture and adopt more sustainable and health-promoting methods for food production,” Hertz-Picciotto said.

She added that the new study was “very well-executed, thoughtful and thorough” and that although replicating the study would be desirable, the findings provide strong evidence that certain pesticides are associated with reproductive concerns.

“The limitation of this study is that the participants were seeking fertility treatments, and hence the results pertain specifically to reproductive potential in a certain subset of women,” she said.

Wash your fruits and veggies

Dr. Jorge Chavarro, an associate professor at the Harvard T.H. Chan School of Public Health and senior author of the study, said he was surprised with the findings.

“Going into the study, I was positive that we would find absolutely no relation between exposure to pesticide residues in fruits and vegetables and adverse reproductive outcomes,” he said. “While I think we need more studies to confirm or refute our findings, I am now more willing to pay the extra money for organic apples and strawberries than I was when we started this project.”

The study found only associations between pesticide residue and pregnancy outcomes — not a causal relationship.

The study also has some limitations. For instance, the women’s diets were assessed using self-reports, which leaves room for error, and the women were trying to become pregnant through infertility treatments. More research is needed to determine whether similar findings would emerge among women trying to conceive naturally. Also, more research is needed to connect specific pesticides with the infertility treatment outcomes seen in the study.

The Alliance for Food and Farming, a nonprofit organization comprising organic and conventional farmers, notes on its website that fruits and vegetables are an important part of a healthy diet and that “the mere presence of pesticide residues on food does not mean they are harmful.”

In general, the Food and Drug Administration recommends consuming fruits and vegetables for good nutrition but following safe handling tips, including thoroughly washing fresh produce under running water before preparing and eating.

On the other hand, “the observations made in this study send a warning that our current laissez-faire attitude toward the regulation of pesticides is failing us,” wrote Dr. Philip Landrigan, dean for global health and professor at the Icahn School of Medicine at Mount Sinai, in an editorial accompanying the study in JAMA Internal Medicine.

“We can no longer afford to assume that new pesticides are harmless until they are definitively proven to cause injury to human health,” he wrote. “We need to overcome the strident objections of the pesticide manufacturing industry, recognize the hidden costs of deregulation, and strengthen requirements for both premarket testing of new pesticides, as well as postmarketing surveillance of exposed populations — exactly as we do for another class of potent, biologically active molecules — drugs.”

What is ‘pumpkin spice,’ anyway? And why do we crave it?

Each fall, as leaves turn golden and the crisp autumn air carries the scent of pine, Catherine Franssen waits for her husband to bring home the latest pumpkin spice-flavored concoction he has discovered at the grocery store.

“My husband — whose favorite pie is pumpkin; he’ll eat it year-round — thinks the pumpkin spice craze is funny and brings home all sorts of odd pumpkin spice items to try,” said Franssen, assistant professor of psychology and director of the neurostudies minor at Longwood University in Virginia.

“I think I ended up eating the entire box of pumpkin-spiced Cheerios last year after the rest of the family tasted and rejected,” she said. “They were pretty good.”

Franssen called the current trendiness of pumpkin spice “a fantastic example of the psychology of consumer behavior and fads.” She knows that the sweet smell and tantalizing taste of pumpkin spice can trigger a nostalgic emotional response in her brain and the brains of many other consumers, she said.

After all, “this spice blend has been used in popular baked goods for quite some time, but mostly in home-baked goods,” said Franssen, who wrote a 2015 blog post in the Huffington Post about the science behind pumpkin spice.

“Since these are popular spice combinations, it’s very likely we would have encountered some or all of them combined in a favorite baked good in a comforting situation, like a family gathering, early in life,” she said. “It’s not just the pumpkin spice combo but that we’ve already wired a subset of those spices as ‘good’ very early in life.”

In other words, if the pumpkin spice blend — or a synthetic version — that has been added to your favorite food item reminds you of a baking pumpkin pie at grandma’s house, then it probably did its job.

What is pumpkin spice anyway?

Most pumpkin spice mixtures don’t involve an actual pumpkin. Typically it contains ground cinnamon, nutmeg, dry ginger and clove or allspice mixed together, said Kantha Shelke, a food science communicator for the Institute of Food Technologists and a scientist at Corvus Blue, a Chicago-based food science and research firm.

When many food companies use a pumpkin spice flavor, they often develop a synthetic version with various compounds and aromas designed to trick your brain into thinking you actually consumed a mix of cinnamon, nutmeg and other spices.

Included in many of these synthetic pumpkin spice flavors are top notes that mimic the aroma of butter browning with sugar, which creates an olfactory illusion of a freshly baked pumpkin pie, Shelke said.

Nonetheless, “history shows that pumpkin spice-like combinations have been used for millennia in various cultures,” said Shelke, who is also an adjunct professor of regulatory science and food safety at Johns Hopkins University.

For instance, similar mixtures of spices are used in Indian masala chai and Middle Eastern baklava, she said. These mixtures are often used in celebratory occasions — most often to ease the digestive impacts of overindulgence, Shelke said.

Yet “in the Western world, the aroma of pumpkin spice immediately transports people to all the warm and friendly times associated with pumpkin pie, holiday gatherings, families, celebrations, treats, sweets … things that childhood memories are made of,” Shelke said. “This is why pumpkin spice latte is trendy.”

Pumpkin spice seems to have emerged as a common seasonal scent and taste in the home and food market a couple of decades ago, when spiced pumpkin candles grew in popularity, Franssen said.

“Then, a few high-profile companies, like Starbucks, run some super successful experiments, and then you add in the fantastic marketing strategies, and you’ve got a fad that turns into a trend,” she said.

Starbucks first developed its pumpkin spice latte, known as the PSL, in early 2003. In a news release last week, Peter Dukes, the product manager who led the development of PSL, said, “Nobody knew back then what it would grow to be. … It’s taken on a life of its own.”

The seasonal beverage, which has its own verified Twitter and Instagram accounts, returned to stores nationwide last week for the fall.

“Marketing is truly the key here, and there’s some incredibly interesting neuroscience going on,” Franssen said.

The marketing behind many pumpkin spice-flavored items, like the latte, condition our brains to expect that pumpkin spice is the flavor of fall and to anticipate the flavor’s arrival each season as something comforting, Franssen said.

“We don’t have innate odor responses. We learn odors through associations, but the associations we make with pumpkin spice are generally all very positive,” she said.

Though, even without the seasonal marketing, the brain has a special response to pumpkin spice when the flavor is mixed with sugar, Franssen said.

‘Actually, scientifically, kind of addictive’

“When an odor or flavor — and 80% of flavor is actually smell — is combined with sucrose or sugar consumption in a hungry person, the person learns at a subconscious, physiological level to associate that flavor with all the wonderful parts of food digestion,” Franssen said.

By combining the recognizable pumpkin spice flavor with sugar, you train your brain and body to remember how delicious the combination is — and as soon as you smell or even imagine pumpkin spice, your body will have an anticipatory response and crave it, Franssen said.

For that reason, “the pumpkin spice latte is actually, scientifically, kind of addictive,” she said. “Not quite the same neural mechanisms as drugs of abuse, but certainly the more you consume, the more you reinforce the behavior and want to consume more.”

On the other hand, natural pumpkin spice mixtures without added sugars, fat or salt could offer some potential health benefits if used in a pumpkin soup or to flavor vegetables, Shelke said. Pumpkin is a source of vitamin A, fiber and other nutrients.

“I love vegetables and consume at least eight to 10 servings of vegetables a day. Pumpkin and its cousins show up in my diet regularly and often with pumpkin spice-like spices,” Shelke said.

“Spices are powerhouses of phytochemicals — chemicals that the plant makes to protect itself — that can afford us health and protection from many health issues. Like with any food, the amount consumed determines the experience and the benefits,” Shelke said.

“All spices come from plants. There are no spices from the animal kingdom,” she said. “So, spices are perfect for vegetarians, vegans and those who follow Halal and Kosher diets.”

So, if you have the craving, enjoy your pumpkin spice and everything nice.

Blood clot risk — and other problems — might be tied to how tall you are

How tall you are might hold clues to your risk of various health problems, such as blood clots, according to a new study.

Height can be an independent predictor of your risk for venous thromboembolism, or VTE, also known as blood clots, according to the study, published Tuesday in the journal Circulation: Cardiovascular Genetics.

That blood clot risk was lowest among the shortest women and men and appeared to increase with height, the research showed.

“Height is not something we can do anything about,” lead study author Dr. Bengt Zöller, associate professor at Lund University and Malmö University Hospital in Sweden, said in a news release.

“However, the height in the population has increased, and continues increasing, which could be contributing to the fact that the incidence of thrombosis has increased,” he said. “I think we should start to include height in risk assessment just as overweight, although formal studies are needed to determine exactly how height interacts with inherited blood disorders and other conditions.”

In the United States, blood clots are thought to kill about 60,000 to 100,000 people annually, according to the US Centers for Disease Control and Prevention.

Across Europe, there are an estimated 500,000 deaths related to blood clots each year, according to a 2014 review paper in the journal Thrombosis Research.

The risk of blood clots isn’t the only health concern that has been tied to height: Cancer, heart problems, gestational diabetes and even longevity have been linked with stature.

‘Body size in general is an important factor’

The new blood clot study involved data on more than 1.6 million Swedish men who enlisted in the military and were born between 1951 and 1992, and data on more than 1 million Swedish women who had a first pregnancy between 1982 and 2012. Pregnancy can increase the risk of blood clots, which is among the leading causes of maternal death in the developed world.

Using the Swedish Multi-generation Register, the researchers identified siblings of different heights. They also used the national Swedish Hospital Register to track hospital inpatient and outpatient diagnoses of blood clots between 1969 and 2012.

The researchers found that the risk for blood clots decreased 69% for women shorter than about 5-foot-1, compared with women about 6 feet and taller. The risk dropped 65% for men shorter than about 5-foot-3, compared with men about 6-foot-2 and taller, the researchers found.

Among men, an association with height was found for risk of blood clots in the lungs, called pulmonary embolism, as well as in the legs and other locations. Among women, only the risk of blood clots in the legs was significantly associated with height.

Still, “these clots are deadly because they can break free from the vein and travel to the lung,” said Dr. Mary Cushman, professor of medicine and pathology and director of the Thrombosis and Hemostasis Program at the Larner College of Medicine at the University of Vermont, who was not involved the new study.

“If the clot is big enough, that can cause death, which is sometimes sudden,” she said.

The researchers also found that the strong association between blood clot risk and height remained among the siblings.

The strengths of the new study are its large sample sizes and its utilization of siblings, said Dr. Nesochi Okeke-Igbokwe, an attending physician of internal medicine at NYU Langone Health in New York, who was not involved in the new study.

“Overall, it is a solid study with good research methodology used,” Okeke-Igbokwe said.

“The bottom line regarding this recent study, whether you are a taller or shorter individual, you must be aware of all the additional lifestyle factors that may increase your risk for blood clots, such as smoking or a sedentary lifestyle,” she said. “We have no control over our height, but we certainly can all take the appropriate measures in making healthy lifestyle choices to reduce the risk of various conditions.”

One limitation of the study was that the researchers did not have information on the participants’ childhoods, home environments and diets. However, they used educational level as a measure of lifestyle factors.

All in all, “this study adds to growing evidence that body size in general is an important factor to consider in determining the risk of VTE. It also gives us information about why VTE occurs in the legs more often than elsewhere, like the arms,” said Cushman, who also serves as editor-in-chief of the journal Research and Practice in Thrombosis and Haemostasis.

“Basically, the blood has to travel up a vein against gravity, and when there is a longer distance to travel, there is more opportunity for the blood to clot abnormally,” she said. “This is not the case in the arms, for example, where arm movement allows blood to more easily flow out of the limb with the help of gravity.”

When it comes to the new study, the “robust” design could be replicated to determine whether height correlates with other health problems, said Ulhas Naik, professor of medicine and director of the Cardeza Center for Vascular Biology Research at the Sidney Kimmel Medical College at Thomas Jefferson University, who was not involved in the new study.

“Being tall, there are benefits in some ways in some diseases, (and) there is the opposite in some other diseases,” he said. “This kind of a study is a good starting point to now look at other diseases.”

Cancer risk goes up with height?

Epidemiological studies have suggested that taller people are at an increased risk of cancer.

A systematic review paper published in the journal Plos Medicine last year, in which 63 studies on the association of height with cancer risk were analyzed, provided evidence for a potential link between adult height and the risk of colorectal and lung cancers.

The paper also suggested that certain genetic factors and biological pathways affecting adult height may affect the risk of those cancers.

A separate study published in the Journal of the National Cancer Institute in 2015 provided strong evidence that adult height can be a risk factor for breast cancer in women.

As with the Plos Medicine study, the researchers behind the 2015 study pointed to certain genetic factors and biological pathways affecting height as having an important role in the development of breast cancer.

Is short stature tied to gestational diabetes risk?

Height also has been linked to gestational diabetes, which occurs when high blood sugar starts or is first diagnosed during pregnancy.

A study of 135,861 pregnancies in women of various races in the US, of whom 5,567 were diagnosed with gestational diabetes, found that taller height was significantly associated with a lower risk of gestational diabetes.

Overall, women in the highest height quartile in that study had more than 60% lower risk of gestational diabetes compared with women in the lowest quartile, even after accounting for maternal age, weight, race, insurance and education, according to the findings.

The study was published in the journal Diabetic Medicine in 2013.

Are your height and heart risk connected?

Researchers have long suspected that being shorter might be tied to an increased risk for certain heart problems, such as heart disease and heart attacks.

On the other hand, atrial fibrillation, a problem with the speed or rhythm of your heart rate, has been observed to be more prevalent among taller individuals.

Overall, a meta-analysis research paper on height and health risks, published in the International Journal of Epidemiology in 2012, found that “height was negatively associated with death from coronary disease, stroke subtypes, heart failure, stomach and oral cancers, chronic obstructive pulmonary disease, mental disorders, liver disease and external causes,” according to the abstract.

“In contrast, height was positively associated with death from ruptured aortic aneurysm, pulmonary embolism, melanoma and cancers of the pancreas, endocrine and nervous systems, ovary, breast, prostate, colorectum, blood and lung,” the abstract said. That study involved an analysis of 121 prospective studies including about 1 million people.

Some studies also suggest that shorter people appear to have longer lifespans on average.

NYU Langone’s Okeke-Igbokwe said that with all of these height-related correlations — from cancer to heart diseases — the exact underlying mechanisms still need to be fleshed out.

“Undoubtedly, an increased number of large-scale studies will still be required to really examine the correlation between height and these other medical conditions,” she said.