Almut Winterstein, University of Florida and Sonja Rasmussen, Johns Hopkins University

A panel convened in July 2025 by the Food and Drug Administration sparked controversy by casting doubt about the safety of commonly used antidepressants during pregnancy. But it also raised the broader issue of how little is known about the safety of many medications used in pregnancy, considering the implications for both mother and child – and how understudied this topic is.

In the U.S., the average pregnant patient takes four prescription medications, and more than 9 in 10 patients take at least one. But most drugs lack conclusive evidence about their safety during pregnancy. About 1 in 5 women uses a medication during pregnancy that has some preliminary evidence that it could cause harm but for which conclusive studies are missing.

We are researchers in maternal and child health who evaluate the safety of medications during pregnancy. In our work, we identify medications that might raise the risk for birth defects or pregnancy loss and compare the safety of different treatments.

While progress has been slow, researchers and federal agencies have built monitoring systems, databases and tools to accelerate our understanding of medication safety. However, these efforts are now at risk due to ongoing cuts to medical research funding – and with them, so is the knowledge base for determining whether sticking with a therapy or discontinuing it offers the safest choice for both mother and child.

How pregnant women got sidelined

One big reason why so little is known about the effects of medications during pregnancy stretches back more than half a century. In the 1960s, a drug called thalidomide that was widely prescribed to treat morning sickness in pregnant women caused severe birth defects in over 10,000 children around the world. In response, in 1977 the FDA recommended excluding women of childbearing age from participating in early stage clinical trials testing new medications.

Ethically, there is long-standing tension between concerns about fetal harm and maternal needs. Legal liability and added complexities when conducting studies in pregnant women serve as additional barriers for drug manufacturers.

When drugs are approved, studies about whether they might cause birth defects are typically done only in animals, and they often don’t translate well to humans. So when a new medication comes on the market, nothing is known about how it affects people during pregnancy. Even if animal studies or the medication’s mode of action raised concerns, the drug can still be approved, though companies may be required to conduct studies observing its effects when taken during pregnancy.

Cause and effect

Of 290 drugs approved by the FDA between 2010 and 2019, 90% contain no human data on the risks or benefits for pregnant patients. About 80% of some 1,800 medications in a national database called TERIS, which summarizes evidence on medications’ risks during pregnancy, lack or have limited evidence about the risks for birth defects. Researchers have estimated that it takes 27 years to pin down whether a medication is safe to use in pregnancy.

As a result, many pregnant women stop treating their chronic diseases. In a U.S. study published in 2023, over one-third of women stopped taking a medication during pregnancy, and 36.5% of those did so without advice from a health care provider. More than half cited concerns about birth or developmental defects as the reason.

Yet uncontrolled chronic disease comes with its own toll on both the mother’s and the baby’s health. For example, some medications used to treat seizures are known to cause birth defects, but stopping them may increase seizures, which themselves raise the risk of fetal death.

Women with severe or recurrent depression who abruptly stop their antidepressants risk their depression returning, which is in turn associated with increased risk of substance use, inadequate prenatal care and other negative effects on fetal development. Stopping the use of medications
for treating high blood pressure also causes adverse effects – specifically, a greater risk of pregnancy-related high blood pressure that can cause organ damage, called preeclampsia; a condition called placental abruption, when the placenta detaches from the wall of the uterus too early; preterm birth; and fetal growth restriction. An online resource called Mother to Baby, created by a network of experts on birth defects, provides an excellent summary of the available data on medication safety during pregnancy.

The FDA in some cases requires drug companies to establish registries to track the outcomes of pregnancies exposed to certain medications. These registries can be useful, but they have shortcomings. For example, recruiting pregnant patients into them takes time and considerable effort, resulting in small sample sizes that may not capture rare birth defects. Also, registries typically follow a single medication and rarely include comparisons to alternative treatment approaches – or to no treatment.

What’s more, following the 2022 Dobbs v. Jackson Supreme Court decision overturning the constitutional right to abortion, women might be reluctant to add their names to a pregnancy registry or to provide data on prenatal detection of birth defects due to concerns about privacy and legal risks.

Decades of underfunding

In 2019, a task force established by the 21st Century Cures Act identified a major gap in knowledge about drug safety and effectiveness in pregnant and lactating women and recommended a boost in funding to fill it.

However, little has changed. A 2025 review by the National Academies of Sciences, Engineering and Medicine pointed out that research funding for women’s health topics has remained flat over the past decade, while the overall budget of the National Institutes of Health has steadily increased. The review recommended doubling the NIH funding allocated for such research, but this seems unlikely in light of the recent proposals to cut the overall NIH budget by 40%.

The National Institute of Child Health and Human Development funds the bulk of research on the safety of medications during pregnancy across federal agencies, although the institute has an appreciably smaller budget than most of its sister institutes such as the National Cancer Institute. Grants awarded are typically broad and take four to five years to complete, but they allow the more comprehensive assessments that are needed to support informed decisions considering outcomes for mother and child. For example, NIH-funded researchers have established a clear link between autism and prenatal use of valproate, a potent teratogen used to treat epilepsy and several mental health disorders.

The Centers for Disease Control and Prevention as well as the FDA have also funded specific pregnancy-related research. For example, following the COVID-19 epidemic, the CDC renewed its funding for studies that help expedite pregnancy safety studies for treatments that might be used for newly emerging infections. In response to emerging concerns about a substance called gadolinium, which is often used during MRI procedures, the FDA funded our own work on a study of almost 6,000 pregnant women, which found no elevated risk.

For healthy pregnancies, more research is critical

These efforts have laid a crucial foundation for evaluating medication safety and effectiveness during pregnancy. But keeping pace with the release of new medications and new ways they are used, as well as addressing the backlog of missing evidence for medications that were approved in the past millennium, remain a challenge.

Recent terminations of NIH-funded studies have focused on topics presumably relating to diversity, equity and inclusion. But research on safe and healthy pregnancies and on maternal health – for example, on the safety of COVID-19 vaccines during breastfeeding – has been affected as well.

The NIH has scaled back new grant awards by nearly US$5 billion since the beginning of 2025, and the odds for receiving NIH funding have plummeted. Proposed sweeping budget cuts for the CDC and FDA leave their role in supporting research on healthy pregnancies similarly uncertain.

In our view, removing or reducing ongoing investments in healthy pregnancies poses a danger to much-needed efforts to reduce excessive rates of stillbirths as well as infant and maternal deaths.

Almut Winterstein, Distinguished Professor of Pharmaceutical Outcomes & Policy, University of Florida and Sonja Rasmussen, Professor of Genetic Medicine, Johns Hopkins University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Juliette Becker, University of Wisconsin-Madison

The Sun will someday die. This will happen when it runs out of hydrogen fuel in its core and can no longer produce energy through nuclear fusion as it does now. The death of the Sun is often thought of as the end of the solar system. But in reality, it may be the beginning of a new phase of life for all the objects living in the solar system.

When stars like the Sun die, they go through a phase of rapid expansion called the Red Giant phase: The radius of the star gets bigger, and its color gets redder. Once the gravity on the star’s surface is no longer strong enough for it to hold on to its outer layers, a large fraction – up to about half – of its mass escapes into space, leaving behind a remnant called a white dwarf.

I am a professor of astronomy at the University of Wisconsin-Madison. In 2020, my colleagues and I discovered the first intact planet orbiting around a white dwarf. Since then, I’ve been fascinated by the prospect of life on planets around these, tiny, dense white dwarfs.

Researchers search for signs of life in the universe by waiting until a planet passes between a star and their telescope’s line of sight. With light from the star illuminating the planet from behind, they can use some simple physics principles to determine the types of molecules present in the planet’s atmosphere.

In 2020, researchers realized they could use this technique for planets orbiting white dwarfs. If such a planet had molecules created by living organisms in its atmosphere, the James Webb Space Telescope would probably be able to spot them when the planet passed in front of its star.

In June 2025, I published a paper answering a question that first started bothering me in 2021: Could an ocean – likely needed to sustain life – even survive on a planet orbiting close to a dead star?

A universe full of white dwarfs

A white dwarf has about half the mass of the Sun, but that mass is compressed into a volume roughly the size of Earth, with its electrons pressed as close together as the laws of physics will allow. The Sun has a radius 109 times the size of Earth’s – this size difference means that an Earth-like planet orbiting a white dwarf could be about the same size as the star itself.

White dwarfs are extremely common: An estimated 10 billion of them exist in our galaxy. And since every low-mass star is destined to eventually become a white dwarf, countless more have yet to form. If it turns out that life can exist on planets orbiting white dwarfs, these stellar remnants could become promising and plentiful targets in the search for life beyond Earth.

But can life even exist on a planet orbiting a white dwarf? Astronomers have known since 2011 that the habitable zone is extremely close to the white dwarf. This zone is the location in a planetary system where liquid water could exist on a planet’s surface. It can’t be too close to the star that the water would boil, nor so far away that it would freeze.

The habitable zone around a white dwarf would be 10 to 100 times closer to the white dwarf than our own habitable zone is to our Sun, since white dwarfs are so much fainter.

The challenge of tidal heating

Being so close to the surface of the white dwarf would bring new challenges to emerging life that more distant planets, like Earth, do not face. One of these is tidal heating.

Tidal forces – the differences in gravitational forces that objects in space exert on different parts of a nearby second object – deform a planet, and the friction causes the material being deformed to heat up. An example of this can be seen on Jupiter’s moon Io.

The forces of gravity exerted by Jupiter’s other moons tug on Io’s orbit, deforming its interior and heating it up, resulting in hundreds of volcanoes erupting constantly across its surface. As a result, no surface water can exist on Io because its surface is too hot.

In contrast, the adjacent moon Europa is also subject to tidal heating, but to a lesser degree, since it’s farther from Jupiter. The heat generated from tidal forces has caused Europa’s ice shell to partially melt, resulting in a subsurface ocean.

Planets in the habitable zone of a white dwarf would have orbits close enough to the star to experience tidal heating, similar to how Io and Europa are heated from their proximity to Jupiter.

This proximity itself can pose a challenge to habitability. If a system has more than one planet, tidal forces from nearby planets could cause the planet’s atmosphere to trap heat until it becomes hotter and hotter, making the planet too hot to have liquid water.

Enduring the red giant phase

Even if there is only one planet in the system, it may not retain its water.

In the process of becoming a white dwarf, a star will expand to 10 to 100 times its original radius during the red giant phase. During that time, anything within that expanded radius will be engulfed and destroyed. In our own solar system, Mercury, Venus and Earth will be destroyed when the Sun eventually becomes a red giant before transitioning into a white dwarf.

For a planet to survive this process, it would have to start out much farther from the star — perhaps at the distance of Jupiter or even beyond.

If a planet starts out that far away, it would need to migrate inward after the white dwarf has formed in order to become habitable. Computer simulations show that this kind of migration is possible, but the process could cause extreme tidal heating that may boil off surface water – similar to how tidal heating causes Io’s volcanism. If the migration generates enough heat, then the planet could lose all its surface water by the time it finally reaches a habitable orbit.

However, if the migration occurs late enough in the white dwarf’s lifetime – after it has cooled and is no longer a hot, bright, newly formed white dwarf – then surface water may not evaporate away.

Under the right conditions, planets orbiting white dwarfs could sustain liquid water and potentially support life.

Search for life on planets orbiting white dwarfs

Astronomers haven’t yet found any Earth-like, habitable exoplanets around white dwarfs. But these planets are difficult to detect.

Traditional detection methods like the transit technique are less effective because white dwarfs are much smaller than typical planet-hosting stars. In the transit technique, astronomers watch for the dips in light that occur when a planet passes in front of its host star from our line of sight. Because white dwarfs are so small, you would have to be very lucky to see a planet passing in front of one.

Nevertheless, researchers are exploring new strategies to detect and characterize these elusive worlds using advanced telescopes such as the Webb telescope.

If habitable planets are found to exist around white dwarfs, it would significantly broaden the range of environments where life might persist, demonstrating that planetary systems may remain viable hosts for life even long after the death of their host star.

Juliette Becker, Assistant Professor of Astronomy, University of Wisconsin-Madison

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Justin Dunnavant, University of California, Los Angeles

“For a long time now, a large number of [escaped slaves] have established themselves on lofty Maroon Hill in the mountains toward the west end of the island [of St. Croix]. … They are there protected by the impenetrable bush and by their own wariness.”

Those are the words of Christian Oldendorp, a Danish missionary who visited the Caribbean island of St. Croix in 1767. His account is one of the few Danish historical records of Maronberg, a community of escaped slaves, known as Maroons, in the northwest mountain ranges of the island.

In 1733, the Danish West India-Guinea Company purchased St. Croix from France and quickly expanded the island’s sugar and cotton production. This also meant expanding the slave population to harvest lucrative plantations. But the Danes were never able to fully control the island – or the enslaved. By the end of the 1700s, nearly 1,400 people – more than 10% of the enslaved population – successfully escaped captivity. But where did they escape to? Only recently have researchers started to shed more light on this centuries-old mystery.

As an archaeologist specializing in slavery and resistance, I’ve excavated plantations in the Americas and used geographic information systems to model Maroon escape routes by sea. Recently, I turned my attention to Maroon settlements on land, working with a team of archaeologists to locate Maronberg.

Honoring a legacy

I first learned about Maronberg on a nature tour of St. Croix given by local activist and University of the Virgin Islands professor Olasee Davis in 2016. At that time, I was on the island to excavate a sugar plantation, a project that gave my colleagues and me a unique perspective on the enslaved experience in the Danish-controlled Caribbean.

In August 2025, Davis’ decades-long campaign to create an official heritage sanctuary to protect Maronberg finally came to fruition. The local government purchased 2,386 acres of land to serve as the U.S. Virgin Islands Maroon Territorial Park.

But one problem remains: We have yet to find the physical remains of the settlement. Locating and preserving Maronberg’s historical artifacts and buildings could provide new insight into residents’ way of life and give greater meaning to the sanctuary.

Fortunately, advanced computer modeling and high-resolution maps are helping us get closer to pinpointing the settlement.

Finding what was meant to remain hidden

Many Maroon settlements in the Americas have proved difficult to locate. This makes sense when you consider that their inhabitants were trying to hide from colonial settlers. If the Danes had found Maronberg, they would have either killed its inhabitants or forced them back into slavery.

Runaways tended to settle in areas that were intentionally difficult to access, like remote swampy or mountainous terrain. Houses and other shelters often consisted of semipermanent structures so that Maroons could relocate as needed to avoid detection.

The boundaries of Maronberg and the size of the settlement along the northwestern mountain range remain unknown. Colonial militias attempted periodic raids, but historical records report that they were met with rugged terrain, booby traps and counterattacks.

The missionary Oldendorp wrote: “[The Maroons] keep every approach safe by attempting carefully to conceal small, pointed stakes of poisoned wood so that the unwary pursuer might wound his foot on them and therefore be prevented from continuing the chase as a result of the unbearable pain.”

All those precautions paid off: The Danes were never able to penetrate the Maroons’ encampment.

Using new tech to see 300 years into the past

Recent attempts by researchers to locate Maronberg began in 2007, with more extensive geographic information systems mapping conducted in 2008. These digital, computer-based geographic programs allow researchers to store a range of geological data and model spatial patterns across vast terrains.

Pairing a historical map with a low-resolution elevation map from the U.S. Geological Survey, archaeologist Bo Ejstrud created a predictive model to assess the probable location of the Maroon settlement. He considered elevation, slope and colonial infrastructure to identify the most remote areas of St. Croix with the least visibility from colonial lines of sight.

Back in the 1700s, urban centers accounted for only a small percentage of the overall landmass of the 83-square-mile (215-square-kilometer) island. Much of the land was either plantations or uninhabited forests and mountains. Ejstrud’s model reaffirmed the likelihood of a Maroon settlement in the northwest region. But it left us with a massive survey area. The map also didn’t account for the possibility that the settlement moved over time.

In 2020, I teamed up with archaeologists Steven Wernke, from Vanderbilt University’s Spatial Analysis Research Laboratory, and Lauren Kohut, from Winthrop University’s Geospatial Environmental Modeling Lab. Together, we developed and visualized a more dynamic model using advances in mapping since 2008.

We began by digitizing two of the most detailed colonial maps of St. Croix – one from 1750 and another from 1799. These maps, created by Danish military engineers and surveyors, detail the spread of plantations, roads and settlements over time.

Next, in order to build a digital elevation model of the island’s terrain, we incorporated high-resolution light detection and ranging, or lidar, data collected by the National Oceanic and Atmospheric Administration. Whereas traditional digital elevation models can be skewed by dense vegetation and trees, lidar uses laser pulses that penetrate through the forest canopy to map the Earth’s surface. This technology allows us to analyze some of the most secluded, inaccessible areas on the island. Prior to 2013, lidar was too costly for archaeological research purposes. But these days, it’s built into many cellphones.

By layering these datasets in geographic information systems software, we created a suitability model that estimated where Maroon settlements were most likely to have existed. In addition to isolation and visibility, we also incorporated accessibility to water sources and terrain ruggedness to model the degree of mobility through the landscape.

This approach allowed us to simulate how the opportunities and constraints the landscape offered to people seeking refuge shifted as colonial society grew over time.

Mapping changes

In addition to providing more nuance to the picture of the areas where Maroons potentially settled, our research suggests that the Maroon settlement wasn’t static, but likely waned as colonial infrastructure increased on the island. Our model implies that the area of suitable land for clandestine Maroon communities shrank by more than 90% in just 50 years.

It’s possible that over time there were fewer runaways. More likely, more Maroons left the island by boat for destinations such as Puerto Rico and Tortola.

Where we go from here

Though our findings still don’t provide an exact location for Maronberg, they get us one step closer to locating the physical remains of this centuries-old Maroon community. The next step will be to visit these sites and survey them for evidence of historical settlement. Archaeological research at these sites would help us understand more about the Maroons who turned a rugged landscape into a sanctuary for freedom.

Ultimately, identifying artifacts and historical sites within the newly established U.S. Virgin Islands Maroon Territorial Park would help us develop educational tours and honor the Maroon legacy.

Justin Dunnavant, Assistant Professor of Anthropology, University of California, Los Angeles

This article is republished from The Conversation under a Creative Commons license. Read the original article.