When the Magellanic Clouds cozy up to each other, stars are born

Like two great songwriters working side by side and inspiring each other to create their best work, the Magellanic Clouds spawn new stars every time the two galaxies meet.

Visible to the naked eye but best seen from the Southern Hemisphere, the Large and Small Magellanic Clouds are by far the most luminous of the many galaxies orbiting the Milky Way. New observations reveal that on multiple occasions the two bright galaxies have minted a rash of stars simultaneously, researchers report March 25 in Monthly Notices of the Royal Astronomical Society: Letters.

Astronomer Pol Massana at the University of Surrey in England and his colleagues examined the Small Magellanic Cloud. Five peaks in the galaxy’s star formation rate — at 3 billion, 2 billion, 1.1 billion and 450 million years ago and at present — match similarly timed peaks in the Large Magellanic Cloud. That’s a sign that one galaxy triggers star formation in the other whenever the two dance close together.
“This is the most detailed star formation history that we’ve ever had of the [Magellanic] Clouds,” says Paul Zivick, an astronomer at Texas A&M University in College Station who was not involved in the new work. “It’s painting a very compelling picture that these two have had a very intense set of interactions over the last two to three gigayears.”

Even as the two galaxies orbit the Milky Way at 160,000 and 200,000 light-years from Earth, they also orbit each other (SN: 1/9/20). Their orbit is elliptical, which means they periodically pass near each other. Just as tides from the moon’s gravity stir the seas, tides from one galaxy’s gravity slosh around the other’s gas, inducing star birth, says study coauthor Gurtina Besla, an astrophysicist at the University of Arizona in Tucson.

During the last encounter, which happened 100 million to 200 million years ago, the smaller galaxy probably smashed right through the larger, Besla says, which sparked the current outbreak of star birth. The last star formation peak in the Large Magellanic Cloud occurred only in its northern section, so she says that’s probably where the collision took place.

Based on the star formation peaks, the period between Magellanic encounters has decreased from a billion to half a billion years. Besla attributes this to a process known as dynamical friction. As the Small Magellanic Cloud orbits its mate, it passes through the larger galaxy’s dark halo, attracting a wake of dark matter behind itself. The gravitational pull of this dark matter wake slows the smaller galaxy, shrinking its orbit and reducing how much time it takes to revolve around the Large Magellanic Cloud.

The future for the two galaxies may not be so starry, however. They recently came the closest they’ve ever been to the Milky Way, and its tides, Besla says, have probably yanked the pair apart. If so, the Magellanic Clouds, now separated by 75,000 light-years, may never approach each other again, putting an end to their most productive episodes of star making, just as musicians sometimes flounder after leaving bandmates to embark on solo careers.

Where you grew up may shape your navigational skills

People who grow up outside of cities are better at finding their way around than urbanites, a large study on navigation suggests. The results, described online March 30 in Nature, hint that learning to handle environmental complexity as a child strengthens mental muscles for spatial skills.

Nearly 400,000 people from 38 countries around the world played a video game called Sea Hero Quest, designed by neuroscientists and game developers as a fun way to glean data about people’s brains. Players piloted a boat in search of various targets.

On average, people who said they had grown up outside of cities, where they would have presumably encountered lots of meandering paths, were better at finding the targets than people who were raised in cities.
What’s more, the difference between city dwellers and outsiders was most prominent in countries where cities tend to have simple, gridlike layouts, such as Chicago with its streets laid out at 90-degree angles. The simpler the cities, the bigger the advantage for people from more rural areas, cognitive scientist Antoine Coutrot of CNRS who is based in Lyon, France, and his colleagues report.

Still, from these video game data, scientists can’t definitively say that the childhood environment is behind the differences in navigation. But it’s plausible. “As a kid, if you are exposed to a complex environment, you learn to find your way, and you develop the right cognitive processes to do so,” Coutrot says.

Other bits of demography have been linked to navigational performance, including age, gender, education and even a superior sense of smell (SN: 10/16/18). Figuring out these details will give doctors a more precise baseline of a person’s navigational abilities. That, in turn, might help reveal when these skills slip, as they do in early Alzheimer’s disease, for instance.

Racial bias can seep into U.S. patients’ medical notes

When health care providers enter notes into patients’ electronic health records, they are more likely to portray Black patients negatively compared with white patients, two recent studies have found. The unfavorable descriptions may perpetuate bias and stigma and influence the care patients receive.

“The first impression is the chart,” says Gracie Himmelstein, a physician training in internal medicine at the UCLA David Geffen School of Medicine. “That narrative is going to shape your views of the patient, even if you think you’re just looking for the clinical data.”

Himmelstein and colleagues analyzed more than 48,000 hospital admission notes from a Boston medical center. Stigmatizing language overall, and about diabetes and substance use disorder in particular, was more often used in the notes of Black patients compared with white patients, the team reported January 27 in JAMA Network Open.
Another study combed through more than 40,000 medical notes from a Chicago medical center. Black patients were more likely to be described as not complying with or resistant to treatment, among other unfavorable terms, a different research group reported in the February Health Affairs.

The two studies appear to be the first to quantify racial bias in the U.S. electronic health record. Bias can drive health disparities — differences in health tied to social, environmental or economic disadvantages — that occur between different racial and ethnic groups. For example, Black infants have a higher mortality rate than white infants due to health disparities (SN: 8/25/20).

The Health Affairs study’s team designed a computer program to look for phrases with negative connotations, including “not compliant,” “not adherent” and “refused,” in medical notes written from January 2019 to October 2020 for close to 18,500 patients. Overall, 8 percent of the patients had one or more negative terms in their electronic health records.

Black patients were 2.5 times more likely to have such words in their medical notes than white patients, the researchers found. This language “has a potential for targeted harm,” says coauthor Michael Sun, a medical student at the University of Chicago’s Pritzker School of Medicine.

Himmelstein and colleagues scrutinized the electronic health record for negative language like “nonadherent” and “unwilling” along with stigmatizing words — including the verb “abuse” — that label or place blame on the patient. The team studied medical notes that were written from January to December in 2018.

Overall, around 1,200, or 2.5 percent, of the admission notes contained unfavorable language. Notes about substance use disorder and diabetes had more of that language woven in, at 3.4 percent and 7 percent, respectively. In the full sample, Black patients were nearly 1.3 times more likely to have stigmatizing terms in their notes than white patients. That factor was about the same when the researchers focused on diabetes notes, while for records about substance use disorder, Black patients were 1.7 times more likely to have negative descriptions.

The new studies didn’t assess what impact the biased notes had on patients’ medical care. But other research has found that when short descriptions of a patient include stigmatizing language, the negative terms influenced physicians’ treatment decisions, making doctors less likely to offer sufficient pain medication.

Along with potentially leading to worse care, bias in medical notes may sour patients’ perception of their providers. Patients now have the right to read their electronic health records, as mandated in the 21st Century Cures Act. Notes that include stigmatizing or biased depictions can “potentially undermine trust,” says primary care doctor and health equity adviser Leonor Fernández of Beth Israel Deaconess Medical Center in Boston.

In a survey of nearly 23,000 patients, Fernández and colleagues found that 10.5 percent felt offended or judged, or both, after reading their own notes, the team reported in the Journal of General Internal Medicine in September 2021. (The survey didn’t ask about discrimination or racial bias specifically.) Many respondents also explained what prompted their feelings. One participant wrote, “Note said I wasn’t doing everything I could to lose weight which was untrue and very upsetting to see my Dr thought of me like that.”

Researchers have written about ways to remove stigma from descriptions of substance use disorder and obesity, among other conditions. This guidance encourages language that does not identify the patient by their illness and that focuses on the efforts a patient is making.

Rather than labeling a person a “diabetic,” for example, health care providers can write that a person “has diabetes,” researchers from a diabetes care task force recommend. And instead of describing a patient as “non-compliant” with their medication, the researchers suggest explaining why, as in, the patient takes insulin “50 percent of the time because of cost concerns.”

By noting the barriers to a patient’s ability to follow medical advice, says Himmelstein, a health care provider can “engage with that in a way that’s actually helpful in promoting health.” Instead of using terms like “non-compliant,” Sun hopes health care providers “think about what other context and what other story” can be told about the patient.

Accounting for the challenges a patient faces “actually makes you more effective” as a health care provider, says Fernández, and makes the patient less likely to feel blamed.

In the Health Affairs study, Sun and his colleagues observed an unexpected and encouraging change in the electronic health record over time. For notes written during the second half of the study, from March to October of 2020, it was no longer more likely that Black patients’ notes had negative terms compared with white patients. That time period coincided with the start of the COVID-19 pandemic and Black Lives Matter protests.

More work is needed to sort out what’s behind the drop, says Sun. He and his coauthors note that health care providers may have considered patients with COVID-19 less responsible for their illness, in contrast to other conditions. But perhaps it has something to do with how “impactful” that period was, Sun says, in raising awareness of racial health disparities. Perhaps the shift was “out of empathy.”

Europa may have much more shallow liquid water than scientists thought

Europa’s frozen surface is covered with distinctive pairs of ridges that straddle troughs of ice. These double ridges are the most common features on the Jovian moon. But scientists don’t yet have a clear idea of how the oddities are created.

Now, an analysis of images of a similar set of ridges on Greenland’s ice sheet suggests that relatively shallow water within Europa’s thick icy shell may be behind their formation, scientists report April 19 in Nature Communications. If so, that could mean that Europa has much more shallow liquid water than scientists have thought.

Europa’s double ridge systems, which can stretch for hundreds of kilometers, include some of the oldest features on the moon, says Riley Culberg, a geophysicist at Stanford University. Some researchers have proposed that the flexing of the moon’s icy shell due to tides in an underlying liquid water ocean plays a role in the ridges’ formation (SN: 8/6/20). Yet others have suggested that water erupted from deep within the icy moon — a process known as cryovolcanism — to create the ridges. Without a closer look, though, it’s been hard to nail down a more solid explanation.
But Culberg and his colleagues seem to have caught a break. Data gathered by NASA’s ICESat-2 satellite in March 2016 showed an 800-meter-long double ridge system in northwestern Greenland. So the team looked back at other images to see when the ridge system first appeared and to assess how it grew. The researchers found that the ridges appeared in images taken as early as July 2013 and are still there today.

When the ridges — which lie on either side of a trough, like those on Europa — reached full size, they averaged only 2.1 meters high. That’s a lot smaller than the ridges on Europa, which can rise 300 meters or more from the moon’s surface. But surface gravity is much lower on Europa, so ridges can grow much larger there, Culberg says. When he and his colleagues considered the difference between Earth’s gravity and Europa’s in their calculations, they found that the proportions of the two ridge systems are consistent.
Scientists will never get a perfect analog of Europa on Earth, but the ridges in Greenland “look just like the Europan ridges,” says Laurent Montési, a geophysicist at the University of Maryland in College Park who was not involved in the study.

Data from airplane-mounted radar gathered in March 2016 show that a water-filled layer of snow about 10 to 15 meters below the surface underlies the Greenland ridges, Culberg and his team say. That water comes from surface meltwater that sinks into and is then collected in the buried snow, which in turn sits atop an impermeable layer of ice.

Repeated freeze-thaw cycles of water in that layer of snow would squeeze water toward the surface, the researchers propose. In the first phase of refreezing, a solid plug of ice forms. Then, as more water freezes, it expands and is forced toward the surface on either side of that plug, pushing material upward and producing the double ridges at the surface.

On Europa, the process works the same way, the researchers suggest. But because there is no known meltwater or precipitation at the moon’s surface, near-surface water there probably would have to come from the ocean thought to be trapped beneath the moon’s icy shell (5/14/18). Once that water rose toward the surface through cracks, it could pool in thick layers of ice shattered by tidal flexing or the impacts of meteorites.

“There’s a general consensus that these ridges grow from cracks in the ice,” says William McKinnon, a planetary scientist at Washington University in Saint Louis who was not involved in the study. “But how do they do it is the question.”

The answer to that question may not be long in coming, McKinnon says. NASA’s Europa Clipper mission is scheduled to launch in late 2024. If all goes well, the orbiter will arrive at Jupiter in April 2030. “If there’s anything like what has happened in Greenland going on at Europa, we’ll be able to see it,” he says.

Researchers will also be interested to see if the mission can ascertain what sort of materials might have been brought to Europa’s surface from the ocean deep below, because the moon is considered to be one of the best places in the solar system to look for extraterrestrial life (SN: 4/8/20).

‘Goldilocks’ stars may pose challenges for any nearby habitable planets

If you’re an aspiring life-form, you might want to steer clear of planets around orange dwarf stars.

Some astronomers have called these orange suns “Goldilocks stars” (SN: 11/18/09). They are dimmer and age more slowly than yellow sunlike stars, thus offering an orbiting planet a more stable climate. But they are brighter and age faster than red dwarfs, which often spew large flares. However, new observations show that orange dwarfs emit lots of ultraviolet light long after birth, potentially endangering planetary atmospheres, researchers report in a paper submitted March 29 at arXiv.org.

Using data from the Hubble Space Telescope, astronomer Tyler Richey-Yowell and her colleagues examined 39 orange dwarfs. Most are moving together through the Milky Way in two separate groups, either 40 million or 650 million years old.
To Richey-Yowell’s surprise, she and her team found that the ultraviolet flux didn’t drop off from the younger orange stars to the older ones — unlike the case for yellow and red stars. “I was like, `What the heck is going on?’” says Richey-Yowell, of Arizona State University in Tempe.

In a stroke of luck, another team of researchers supplied part of the answer. As yellow sunlike stars age, they spin more slowly, causing them to be less active and emit less UV radiation. But for orange dwarfs, this steady spin-down stalls when the stars are roughly a billion years old, astronomer Jason Lee Curtis at Columbia University and colleagues reported in 2019.

“[Orange] stars are just much more active for a longer time than we thought they were,” Richey-Yowell says. That means these possibly not-so-Goldilocks stars probably maintain high levels of UV light for more than a billion years.

And that puts any potential life-forms inhabiting orbiting planets on notice. Far-ultraviolet light — whose photons, or particles of light, have much more energy than the UV photons that give you vitamin D — tears molecules in a planet’s atmosphere apart. That leaves behind individual atoms and electrically charged atoms and groups of atoms known as ions. Then the star’s wind — its outflow of particles — can carry the ions away, stripping the planet of its air.

But not all hope is lost for aspiring life-forms that have an orange dwarf sun. Prolonged exposure to far-ultraviolet light can stress planets but doesn’t necessarily doom them to be barren, says Ed Guinan, an astronomer at Villanova University in Pennsylvania who was not involved in the new work. “As long as the planet has a strong magnetic field, you’re more or less OK,” he says.

Though far-ultraviolet light splits water and other molecules in a planet’s atmosphere, the star’s wind can’t remove the resulting ions if a magnetic field as strong as Earth’s protects them. “That’s why the Earth survived” as a life-bearing world, Guinan says. In contrast, Venus might never have had a magnetic field, and Mars lost its magnetic field early on and most of its air soon after.

“If the planet doesn’t have a magnetic field or has a weak one,” Guinan says, “the game is over.”

What’s needed, Richey-Yowell says, is a study of older orange dwarfs to see exactly when their UV output declines. That will be a challenge, though. The easiest way to find stars of known age is to study a cluster of stars, but most star clusters get ripped apart well before their billionth birthday (SN: 7/24/20). As a result, star clusters somewhat older than this age are rare, which means the nearest examples are distant and harder to observe.

Why taking medications during pregnancy is so confusing

Obstetrician Cynthia Gyamfi-Bannerman was treating patients in New York City when the COVID-19 pandemic swept in. Hospitals began filling up. Some of her pregnant patients were among the sick.

It was a terrifying time. Little was known about the virus called SARS-CoV-2 to begin with, much less how it might affect a pregnancy, so doctors had to make tough calls. Gyamfi-Bannerman remembers doctors getting waivers to administer the antiviral drug remdesivir to pregnant COVID-19 patients, for instance, even though the drug hadn’t been tested during pregnancy.

“Our goal is to help the mom,” she says. “If we had something that might save her life — or she might die — we were 100 percent using all of those medications.”

These life-or-death decisions were very familiar to obstetricians even before the pandemic. Pregnant women have long been excluded from most drug testing to avoid risk to the fetus. As a result, there’s little data on whether many medications are safe to take while pregnant. This means tough choices for the roughly 80 percent of women who will take at least one medication during pregnancy. Some have serious conditions that can be dangerous for both mother and fetus if left untreated, like high blood pressure or diabetes.

“Pregnant women are essentially like everybody else,” Gyamfi-Bannerman says. They have the same underlying conditions, requiring the same drugs. In a 2013 study, the top 20 prescriptions taken during the first trimester included antibiotics, asthma and allergy drugs, metformin for diabetes, and antidepressants. Yet even for common drugs, the only advice available if you’re pregnant is “talk to your doctor.” With no data, doctors don’t have the answers either.

What’s frustrating to many doctors and researchers is that this lack of information is by design. Even the later stages of most clinical trials, which test a new drug’s safety and efficacy in people, specifically exclude pregnant people to avoid risk to the fetus. But in the wake of a pandemic that disproportionately harmed the pregnant population, researchers are questioning more than ever whether this is the best approach.

Typically, researchers have to justify excluding certain groups, such as older adults, from clinical trials in which they might benefit. “You never have to justify why you’re excluding pregnant people,” says Gyamfi-Bannerman, who now heads the obstetrics, gynecology and reproductive science department at the University of California, San Diego. “You can just go ahead and exclude them.

“The exclusion of pregnant people in clinical trials is a huge, historic problem,” she says, “and it really came to light with COVID.”

Pregnant in a crisis
Teresa Mathews was 43 years old when she found out she was pregnant in June 2020, just as the pandemic was tearing across the United States. “I was really worried,” she says. In addition to her age as a risk factor, Mathews has sickle cell trait, meaning she carries one defective gene copy that makes her prone to anemia and shortness of breath. COVID-19 also causes shortness of breath, so Mathews feared her unborn child could starve for oxygen if she caught the virus.

What’s more, the baby would be her first. “I don’t want to say it melodramatically, but it was my last chance of having a baby, right? So I didn’t really want to take chances.” She went into full lockdown for the rest of her pregnancy.

For good reason. A study during the pandemic’s first year in England found that pregnant women who got the virus were about twice as likely to have a stillbirth or early birth. And the U.S. Centers for Disease Control and Prevention reported in November 2020 that pregnant women are about three times as likely as other women to land in intensive care with COVID-19, and 70 percent more likely to die from the infection (SN Online: 2/7/22).
So when the race for a vaccine began, many doctors and officials hoped that vaccines would be tested in pregnant women and shown to be safe. There were promising signs: The U.S. Food and Drug Administration encouraged vaccine developers to include pregnant women in their trials. A large body of previous research suggested that risks would be low for vaccines like those for COVID-19, which do not contain live viruses.

But ultimately the three vaccines that the FDA cleared for use in the United States, from Pfizer/BioNTech, Moderna and Johnson & Johnson, excluded pregnant people from their initial clinical trials. After its vaccine was authorized for emergency use in December 2020, Pfizer began enrolling pregnant women for a clinical trial but called it off when federal officials recommended that all pregnant women get vaccinated. The company cited challenges with enrolling enough women for the trial, as well as ethical considerations in giving a placebo to pregnant individuals once the vaccine was recommended.

When pregnant people were excluded from vaccine trials, doctors knew it would be difficult to convince pregnant patients to take a vaccine that hadn’t been tested during pregnancy.

Mathews says she would have been willing to get vaccinated while pregnant if there had been data to support the decision. But the choice was made for her. Her daughter, Eulalia, was born healthy in February 2021, shortly before the vaccines became available to all adults in Mathews’ hometown of Knoxville, Tenn. At that point, there was still no clear guidance on whether to get vaccinated while pregnant or nursing.
Officials at the National Institutes of Health in Bethesda, Md., were worried about that lack of direction. Diana Bianchi, director of the National Institute of Child Health and Human Development, called for more COVID-19 vaccine research in the pregnant population in a February 2021 commentary in JAMA. She wrote, “Pregnant people and their clinicians must make real-time decisions based on little or no scientific evidence.”

Meanwhile, social media and pregnancy websites filled the void with conspiracy theories and scary stories about vaccines causing infertility or miscarriages. Alarmed, the American College of Obstetricians and Gynecologists warned last October that “the spread of misinformation and mistrust in doctors and science is contributing to staggeringly low vaccination rates among pregnant people.”

Indeed, the CDC had issued an urgent health advisory the month before warning that only 31 percent of pregnant people were fully vaccinated, compared with about 56 percent of the general population. (CDC and many experts favor “pregnant people” as a general term. Science News is following the language used by sources, and refers to pregnant women when a study population was designated as such.)

“Every week, I look at the number of pregnant people who have died due to COVID. Right now, the most recent statistic is 257 deaths,” Bianchi said in January. “I look at that and I say, that was a preventable statistic.”

After the vaccines received emergency use authorization, the CDC analyzed the outcomes for nearly 2,500 vaccinated pregnant people and found no safety concerns related to pregnancy. The agency recommended vaccination for anyone who is pregnant, lactating or considering becoming pregnant. But that recommendation arrived more than six months after the first vaccine became available.
Since then, the vaccines have also proved to be highly effective in pregnancy. More than 98 percent of COVID-19 critical care admissions in a group of more than 130,000 pregnant women in Scotland were unvaccinated, researchers reported in January in Nature Medicine. And all of the infants who died had unvaccinated moms.

“The story of COVID is yet another cautionary tale,” says Anne Lyerly, a bioethicist at the University of North Carolina at Chapel Hill who trained as an obstetrician and gynecologist. “It highlighted what we’re up against.” Researchers have an ethical duty, she says, not only to protect fetuses from the potential risks of research, but also to ensure that “the drugs that go on the market are safe and effective for all the people who will take them.”

Good intentions
Increasingly, scientists are questioning what Gyamfi-Bannerman calls a “knee-jerk” tendency to exclude pregnant individuals from clinical trials. In 2009, Lyerly and colleagues formed the Second Wave Initiative to promote ethical ways to include pregnant women in research. As their ideas have spread, more researchers — mostly women — have held conferences and spearheaded research. Collectively, they’re pushing back on the prevailing culture “that pregnant people need to be protected from research instead of protected through research,” Bianchi says.

“We got here with good intentions,” says Brookie Best, a clinical pharmacologist at UC San Diego who studies medication use among pregnant people. “There were some terrible, terrible tragedies of pregnant people taking a drug and having bad outcomes.”

The most famous of these was thalidomide. Starting in the late 1950s, the drug was prescribed for morning sickness, but it had never been tested in pregnant people. By the early 1960s, it became clear that it caused birth defects including missing or malformed limbs (SN: 7/14/62, p. 22). Afterward, drug companies were reluctant to take on the risk, or legal liability, of potential birth defects. While the FDA enacted new safety rules in response to the thalidomide disaster, the agency did not require testing during pregnancy before drugs went to market.

In 1977, the FDA recommended the exclusion of all women of childbearing age from the first two phases of clinical trials. When the U.S. Congress passed a bill in 1993 requiring that women and minorities be included in clinical research, the requirement did not extend to pregnant women.
Some scientists still see plenty of good reasons not to include pregnant women in clinical trials. For example, reproductive epidemiologist Shanna Swan has seen unexpected health effects crop up long after substances were deemed safe. With that in mind, Swan, of the Icahn School of Medicine at Mount Sinai in New York City, says that observational studies that follow women and their children after a drug has been approved remain the best approach. These studies are “expensive, and very slow,” she admits, but safer.

For decades, that level of precaution has extended to essentially all medications. As a result, the reproductive effects of a medicine aren’t usually discovered until long after a drug enters the market. Even then, such research is not required for most new drugs, so doctors and researchers must take the initiative. Typically, this happens through pregnancy registries, which enroll pregnant volunteers who are taking a particular drug and follow them throughout pregnancy or beyond.

But voluntary registries leave huge data gaps. A 2011 review of 172 drugs approved by the FDA in the preceding decade found that the risk of harm to fetal development was “undetermined” for 98 percent of them, and for 73 percent there was no safety data during pregnancy at all.

That doesn’t mean all those drugs are dangerous. Relatively few drugs cause major birth defects, and many of those fall into known classes. For example, ACE inhibitors used to control blood pressure have been linked to a range of issues, including kidney and cardiovascular problems in infants, when taken during pregnancy. But the potential for more subtle, long-term effects has been trickier to tease out.

For instance, several studies in the 2010s reported links between mothers taking antidepressants during pregnancy and their kids having developmental problems like attention-deficit/hyperactivity disorder and autism spectrum disorder. Some moms became afraid to treat their own depression. But in 2017, studies of siblings found no difference in these conditions among children who had been exposed to antidepressants in the womb and those who had not (SN: 5/13/17, p. 9). More likely, the problem was the depression the mom was experiencing, the studies suggested, not the drugs.

No legal requirement
How the contents of a pregnant woman’s medicine cabinet might affect her child depends on a host of factors, including how the drug works and whether it crosses the placenta. The main way to gauge whether a drug may harm a fetus is through animal studies called developmental and reproductive toxicology, or DART, studies. But drug companies often don’t begin these studies until they’ve already gotten clinical trials rolling.

This creates a catch-22, because clinical trials can’t include pregnant people until DART studies suggest it’s safe to do so. That’s why Lyerly and others pushing for change say that pharmaceutical companies should start doing these studies earlier, before clinical trials begin.

In 2018, the FDA issued draft guidance to help the pharmaceutical industry decide how and when to include pregnant people in clinical trials (SN Online: 5/30/18). That guidance is an encouraging first step, Lyerly says, but it didn’t change any of the stringent rules for when pregnant people could be included in research.

Plus, it’s all completely voluntary, says Leyla Sahin, acting deputy director for safety in FDA’s Division of Pediatric and Maternal Health. “We advise industry…. We tell them we recommend that you include pregnant women in your clinical trials,” Sahin says. “But there’s no requirement.”

In fact, the FDA doesn’t even have the legal authority to create a requirement. In that sense, Sahin says, “we’re where pediatrics was 20 years ago.” Until Congress passed the Pediatric Research Equity Act of 2003, children were routinely excluded from clinical trials just as pregnant women are now. The pediatric law required drug companies to gather data on the safety and effectiveness of medications in children and to provide FDA an appropriate plan for pediatric studies.

Congress could pass a similar law for pregnancy. And in 2020, a government task force recommended exactly that to the Department of Health and Human Services, which oversees FDA. But “it’s almost like it’s gone into this black hole,” Sahin says. “We haven’t heard from HHS. We haven’t heard from Congress.”
Stocking the medicine cabinet
Until clinical trials during pregnancy become more routine, pregnant people face an untenable choice — take a drug without knowing its safety, or leave their medical conditions untreated.

Case in point: A group of 91 doctors and scientists published a consensus statement in September 2021 in Nature Reviews Endocrinology warning that acetaminophen, the most commonly used drug during pregnancy, may harm fetal development. Research suggests the drug disrupts hormones, with effects ranging from undescended testicles in male infants to an increased risk of ADHD and autism spectrum disorder in boys and girls.

But as is often the case with drugs and pregnancy, there’s not exactly a consensus among doctors about what pregnant people should do. In response to the new paper, the American College of Obstetricians and Gynecologists issued a statement saying the evidence wasn’t strong enough to suggest doctors should change their standard practice, which is to recommend acetaminophen be taken as needed and in moderation.

Acetaminophen is an active ingredient in more than 600 medications, including Tylenol, and is estimated to be used by up to 65 percent of pregnant people in the United States. It has long been the preferred pain medication and fever reducer during pregnancy because the FDA recommends against the anti-inflammatory drugs known as NSAIDs — such as ibuprofen and aspirin — in the second half of pregnancy. Those drugs have been linked to rare fetal kidney problems and low amniotic fluid levels.

While at the University of Copenhagen, clinical pharmacologist David Kristensen began studying acetaminophen’s effects on fetal development after noticing that the drug is structurally similar to chemicals that disrupt hormones. In 2011, he and colleagues published animal and human studies linking acetaminophen use during pregnancy with concerning effects in infants, including undescended testicles.

“My ears perked up when I heard that,” says Swan, the Mount Sinai reproductive epidemiologist and coauthor of the 2021 acetaminophen review. She had seen similar effects with maternal exposure to phthalates, chemicals used in plastics that are known to alter the activity of hormones needed to regulate fetal development.

She and colleagues surveyed 25 years of acetaminophen studies. The group found that five out of 11 relevant studies linked prenatal acetaminophen use to urogenital and reproductive tract abnormalities in children, and 26 out of 29 epidemiological studies linked fetal exposure to acetaminophen with neurodevelopmental and behavioral problems. The strength of these links varied, but were “generally modest,” the authors wrote.

“We’re looking at subtle effects here,” Swan says, “but that doesn’t mean that they’re not important.” With such widespread use, “there’s a good chance that a fair number of offspring are affected.”

Although Swan is wary of testing new drugs in pregnant women, she would like to see better research on medications during pregnancy. “There’s a whole range of options short of doing human study,” she says.

To start with, Swan says, scientists need better data on what medications pregnant women are taking, and how much. That means more studies should ask women to keep daily logs of every pill they take. Researchers can also do more studies of drugs’ reproductive effects in animals, she notes, and even transplant human tissues such as brain, liver or gonads into animals to learn how they respond to drugs.

Not the same vulnerability
The cultural shift around pregnancy research may be gaining momentum.

Government-funded research is one key area for change. In 2016, the 21st Century Cures Act established an interagency task force on research specific to pregnant and lactating women. It included officials from NIH, CDC and FDA, as well as medical societies and industry. One of the task force’s recommendations was acted upon in 2018: removing pregnant women as a “vulnerable” group in a federal regulation called the Common Rule, which governs federally funded research. Pregnant women had been listed along with children, prisoners and people with intellectual disabilities as vulnerable and thus requiring special protections if included in research.

Unlike the other groups in that list, pregnant people “don’t have a diminished capacity to provide informed consent,” says Lyerly, the bioethicist at the University of North Carolina. That rule change alone could help “change the culture of research.”

Meanwhile, researchers are forging ahead with studies on many drugs used during pregnancy. HIV drugs are among the most studied, says Best of UC San Diego, in part because the virus can pass from pregnant women to their fetuses. “So right off the bat, everybody knew that we needed to treat these [pregnant] patients with medication,” she says. Yet data on HIV drugs during pregnancy lagged as much as 12 years after FDA approval.
Many pregnant women appear to be willing to participate in research. More than 18,000 pregnant people had enrolled in the COVID-19 vaccine pregnancy registry as of March, and every year many volunteer for other pregnancy registries.

Gyamfi-Bannerman says that in her experience, plenty of pregnant patients are willing to volunteer, even for experimental drugs, if there’s potential to benefit from the drug and they will be monitored closely. At Columbia University, she helped lead a clinical trials network called the Maternal Fetal Medicine Units Network that specifically studies complications during pregnancy. “It’s a very safe and protective environment,” she says.

As for next steps, a few policy changes could make a big difference, Best says, like “getting those preclinical studies done earlier and allowing people who accidentally get pregnant while participating in a clinical trial to make the choice of whether or not to stay.” Right now, “if you get pregnant, you’re out. Boom, that’s it,” she says. “But they were already exposed to the risk, and now they’re not getting the benefit. And so we don’t think that’s actually ethical.”

Thalidomide was prescribed to pregnant women to treat morning sickness, without ever having been tested in pregnant women. “We took the wrong lesson from thalidomide,” Lyerly says. “The first lesson of thalidomide is that we should do research, not that we shouldn’t.”

Gravitational waves gave a new black hole a high-speed ‘kick’

This black hole really knows how to kick back.

Scientists recently observed two black holes that united into one, and in the process got a “kick” that flung the newly formed black hole away at high speed. That black hole zoomed off at about 5 million kilometers per hour, give or take a few million, researchers report in a paper in press in Physical Review Letters. That’s blazingly quick: The speed of light is just 200 times as fast.

Ripples in spacetime, called gravitational waves, launched the black hole on its breakneck exit. As any two paired-up black holes spiral inward and coalesce, they emit these ripples, which stretch and squeeze space. If those gravitational waves are shot off into the cosmos in one direction preferentially, the black hole will recoil in response.
It’s akin to a gun kicking back after shooting a bullet, says astrophysicist Vijay Varma of the Max Planck Institute for Gravitational Physics in Potsdam, Germany.

Gravitational wave observatories LIGO and Virgo, located in the United States and Italy, detected the black holes’ spacetime ripples when they reached Earth on January 29, 2020. Those waves revealed details of how the black holes merged, hinting that a large kick was probable. As the black holes orbited one another, the plane in which they orbited rotated, or precessed, similar to how a top wobbles as it spins. Precessing black holes are expected to get bigger kicks when they merge.

So Varma and colleagues delved deeper into the data, gauging whether the black hole got the boot. To estimate the kick velocity, the researchers compared the data with various predicted versions of black hole mergers, created based on computer simulations that solve the equations of general relativity, Einstein’s theory of gravity (SN: 2/3/21). The recoil was so large, the researchers found, that the black hole was probably ejected from its home and kicked to the cosmic curb.

Dense groups of stars and black holes called globular clusters are one locale where black holes are thought to partner up and merge. The probability that the kicked black hole would stay within a globular cluster home is only about 0.5 percent, the team calculated. For a black hole in another type of dense environment, called a nuclear star cluster, the probability of sticking around was about 8 percent.

The black hole’s great escape could have big implications. LIGO and Virgo detect mergers of stellar-mass black holes, which form when a star explodes in a supernova and collapses into a black hole. Scientists want to understand if black holes that partner up in crowded clusters could partner up again, going through multiple rounds of melding. If they do, that could help explain some surprisingly bulky black holes previously seen in mergers (SN: 9/2/20). But if merged black holes commonly get rocketed away from home, that would make multiple mergers less likely.

“Kicks are very important in understanding how heavy stellar-mass black holes form,” Varma says.

Previously, astronomers have gleaned evidence of gravitational waves giving big kicks to supermassive black holes, the much larger beasts found at the centers of galaxies (SN: 3/28/17). But that conclusion hinges on observations of light, rather than gravitational waves. “Gravitational waves, in a way, are cleaner and easier to interpret,” says astrophysicist Manuela Campanelli of the Rochester Institute of Technology in New York, who was not involved in the new study.

LIGO and Virgo data had already revealed some evidence of black holes getting small kicks. The new study is the first to report using gravitational waves to spot a black hole on the receiving end of a large kick.

That big kick isn’t a surprise, Campanelli says. Earlier theoretical predictions by Campanelli and colleagues suggested that such powerful kicks were possible. “It’s always exciting when someone can measure from observations what you predicted from calculations.”

Scientists made a Möbius strip out of a tiny carbon nanobelt

From cylindrical nanotubes to the hollow spheres known as buckyballs, carbon is famous for forming tiny, complex nanostructures (SN: 8/15/19). Now, scientists have added a new geometry to the list: a twisted strip called a Möbius carbon nanobelt.

Möbius strips are twisted bands that are famous in mathematics for their weird properties. A rubber band, for example, has an inside and an outside. But if you cut the rubber band crosswise, twist one end and glue it back together, you get a Möbius strip, which has only one face (SN: 7/24/07).

In 2017, researchers created carbon nanobelts, thin loops of carbon that are like tiny slices of a carbon nanotube. That feat suggested it might be possible to create a nanobelt with a twist, a Möbius carbon nanobelt. To make the itsy-bitsy twisty carbon, some of the same researchers stitched together individual smaller molecules using a series of 14 chemical reactions, chemist Yasutomo Segawa of the Institute for Molecular Science in Okazaki, Japan, and colleagues report May 19 in Nature Synthesis.

While carbon nanotubes can be used to make new types of computer chips and added to textiles to create fabric with unusual properties, scientists don’t yet know of any practical applications for the twisty nanobelts (SN: 8/28/19; SN: 2/8/19). But, Segawa says, the work improves scientists’ ability to make tiny carbon structures, especially complicated ones.