At the center of Faas’s research is a question that has followed her throughout her career: how does the maternal immune system change during pregnancy, and what happens when those adaptations do not proceed normally?

Her work spans reproductive immunology, preeclampsia, and, increasingly, the relationship between the gut microbiome and maternal immune responses. Using both experimental models and studies involving pregnant women, her group has examined how changes in microbiota may influence immunity during pregnancy and how factors such as maternal obesity can affect maternal and fetal outcomes.

She is particularly interested in understanding these immune responses in greater detail and ultimately identifying ways of improving outcomes for women at risk of pregnancy complications.

Faas’s involvement with preeclampsia began early in her scientific career. Her doctoral research focused on an experimental model of preeclampsia, examining mechanisms involved in the development of a preeclampsia-like condition in pregnancy.

Following her PhD, she continued studying the idea of preeclampsia as an inflammatory disease, first in Groningen and later during postdoctoral research at the University of Oxford. That work helped establish a research path that has continued for decades: understanding the immune system in normal pregnancy and determining how that response differs in preeclampsia.

For Faas, the scientific questions are closely connected to their eventual purpose — improving the health of pregnant women and their babies.

One of the greatest changes Faas has seen is the extraordinary development of the technologies available to researchers.

Techniques now allow scientists to investigate pregnancy at a level of detail that was not possible when she began her career. Advances in sequencing and other molecular approaches make it possible to examine broad biological differences between uncomplicated pregnancies and pregnancies affected by complications, while increasingly sophisticated immunological techniques allow researchers to characterize individual cells and responses in far greater depth.

At the same time, these advances generate new questions. Greater amounts of biological information do not automatically explain why a complication develops, making the challenge of connecting molecular findings with the whole pregnancy increasingly important.

Faas sees promise in understanding how modifiable factors may influence immune responses during pregnancy.

Her group’s work has included experimental studies of the gut microbiome and maternal immunity, including how interventions affecting the microbiome can change immune responses in pregnant mice. This research raises important questions about whether nutrition, dietary components, probiotics, or other approaches targeting the microbiome might eventually help support healthier maternal immune adaptations.

The goal is translational: to understand the mechanisms well enough that research can eventually make a meaningful difference for pregnant women, particularly those at greater risk of complications.

For Faas, some of the most important unanswered questions return to the placenta.

Why does placental development become abnormal in some pregnancies? What initiates those changes, and how do alterations at the maternal–placental interface contribute to the immune and vascular responses associated with disorders such as preeclampsia?

Despite major advances in understanding the immune system and placenta, determining why abnormal placental development occurs in the first place remains a fundamental challenge.

Faas has been part of the ISSHP community for many years, presenting research at meetings across the world and becoming involved in the Society’s leadership.

She recalls ISSHP meetings as places where scientists and clinicians can learn directly from one another. As a biomedical scientist rather than a clinician, this exchange has been especially valuable: the Society brings laboratory research into conversation with the clinical realities of hypertensive disorders of pregnancy.

ISSHP has also created relationships that developed into scientific collaborations. Her career has included work with fellow members including Chris Redman and Annetine Staff, among many other international colleagues. These scientific collaborations also turned into friendly relationships and friendships.

For Faas, the community is therefore more than a scientific meeting. It is a place to learn from different disciplines, exchange ideas, and build collaborations around the shared goal of understanding and improving hypertensive pregnancy disorders.

Faas’s advice is simple: persistence matters.

“Be persistent. Funding is always difficult. Keep on going.”

A research career inevitably comes with unsuccessful grants, experiments that do not work as expected, and questions that take years to answer. Her message to younger scientists is not to let those obstacles end their curiosity.

The reason to continue is the possibility that, over time, persistent research can translate into better understanding and ultimately healthier pregnancies.

After decades of studying pregnancy, there are still fundamental questions without answers — and that is part of what keeps Faas interested.

Pregnancy requires remarkable adaptations in the maternal immune system, yet researchers are still working to understand precisely how those adaptations are regulated, what role the placenta and microbiome play, and why the process becomes disrupted in conditions such as preeclampsia.

Behind those scientific questions is a practical motivation: the possibility that understanding these mechanisms can eventually improve pregnancy outcomes.

“In the end, we might be able to help pregnant women and [support] healthy pregnancies.”

Away from the laboratory and university, Faas enjoys hiking and reading detective novels.