Findings May Advance Understanding of
Infertility in Mothers
NEW YORK,
March 5,
2025 /PRNewswire/ -- Oxytocin, a hormone already
known for its role in childbirth, milk release, and mother-infant
bonding, may have a newfound purpose in mammalian reproduction. In
times of maternal stress, the hormone can delay an embryo's
development for days to weeks after conception, a new study in
rodents shows. According to the authors, the findings about
so-called "diapause" may offer new insights into pregnancy and
fertility issues faced by humans.
Led by researchers at NYU Langone Health, the
study explored diapause, in which an embryo temporarily stops
growing early in its development before it attaches to the lining
of its mother's uterus, a key step leading to the formation of the
placenta. Known to occur in species ranging from armadillos to
giant pandas to seals, diapause is thought to have evolved to help
expectant mothers preserve scarce resources (e.g., breast milk) by
delaying birth until they have enough to successfully take care of
their offspring.
Although recent studies have uncovered evidence
that a form of diapause may occur in humans, the underlying
mechanisms behind it have until now remained unclear.
The findings in mice showed that one type of stress that may
cause diapause is milk production and release (lactation), as it
requires a mother to expend bodily nutrients to both nursing,
already-born pups and to those growing in the womb. The study
revealed that the time between conception and birth (gestation) —
typically 20 days for these animals – was delayed by about a week
in pregnant rodents that were already nursing a litter.
Further, the research team showed that this delay
was brought about by a rise in the production of oxytocin, levels
of which are known to go up as a mother lactates. To confirm this
role for the hormone, the researchers exposed mouse embryos in the
lab to a single dose (either 1 microgram or 10 micrograms) of
oxytocin, and found that even these small amounts delayed their
implantation in the uterus by as much as three days. Beyond just
pausing pregnancy, the team found that surges of the chemical large
enough to that mimic the amounts and timing measured during nursing
caused loss of pregnancy in the mice in nearly all cases.
"Our findings shed light on the role of oxytocin
in diapause," said study co-author Moses
Chao, PhD, a professor in the Departments of Cell Biology,
Neuroscience, and Psychiatry at NYU Grossman School of Medicine.
"Because of this newfound connection, it is possible that
abnormalities in the production of this hormone could play roles in
infertility, premature or delayed birth, and miscarriage."
A report on the findings is publishing online
March 5 in the journal Science
Advances in a special issue focused on women's health.
In another part of the study, the team searched
for a mechanism that would allow embryos to react to an oxytocin
surge. They found that the hormone can bind to special proteins
called receptors on the surface of a layer of cells known as the
trophectoderm, which surrounds the early embryo and eventually
forms the placenta.
Notably, mouse embryos that were genetically
altered to disable oxytocin receptors lived long enough to implant
into their mother's placenta at much lower rates than normal
embryos. This suggests that the ability to respond to oxytocin
spikes, and therefore go into diapause, is somehow important for
the developing pups' survival, says Chao, who plans to examine this
protective function in more detail.
"Despite being extremely common, infertility and
developmental issues that can arise during pregnancy remain poorly
understood and can have a lasting, devastating impact on parents
and their children," said study senior author Robert Froemke, PhD. "Having a deeper
understanding of the factors that contribute to these problems may
allow experts to better address them in the future," added Froemke,
the Skirball Professor of Genetics in the Department of
Neuroscience at NYU Grossman School of Medicine.
Also a professor in the Department of
Otolaryngology—Head and Neck Surgery, Froemke says that the
researchers next plan to examine how cell growth gets turned back
on after diapause. In addition, the team plans to explore how
diapause may affect offsprings' health and development after birth,
and determine whether and how their discoveries can inform
reproductive medicine.
Froemke cautions that while the study results are
promising, mice and humans — while both mammals — have significant
differences in their reproductive processes. He adds that the
current investigation did not assess the role that other
pregnancy-related hormones, such as estrogen and progesterone, may
play in diapause. Froemke is also a member of NYU Grossman School
of Medicine's Institute for Translational Neuroscience.
Funding for the study was provided by National
Institutes of Health grants T32MH019524, NS107616, and
HD088411.
In addition to Moses and Froemke, other NYU
Langone researchers involved in the study are Luisa Schuster, PhD; Habon Issa, PhD; Janaye
Stephens, BS; Michael Cammer,
MFA, MAT; Latika Khatri;
Maria Alvarado-Torres; Jie Tong, PhD; Orlando Aristizábal, MPhil;
Youssef Wadghiri, PhD; Sang Yong
Kim, PhD; Catherine Pei-ju Lu, PhD; and Silvana Valtcheva, PhD. Jessica Minder, PhD, a former graduate student
at NYU Langone and a current postdoctoral associate at the
University of California, Berkeley,
served as the study lead author.
About NYU Langone Health
NYU Langone
Health is a fully integrated health system that consistently
achieves the best patient outcomes through a rigorous focus on
quality that has resulted in some of the lowest mortality rates in
the nation. Vizient, Inc., has ranked NYU Langone the No. 1
comprehensive academic medical center in the country for three
years in a row, and U.S. News & World Report recently placed
nine of its clinical specialties among the top five in the nation.
NYU Langone offers a comprehensive range of medical services with
one high standard of care across seven inpatient locations, its
Perlmutter Cancer Center, and more than 300 outpatient locations in
the New York area and Florida. With $14.2
billion in revenue this year, the system also includes two
tuition-free medical schools, in Manhattan and on Long Island, and a vast research enterprise
with over $1 billion in active awards
from the National Institutes of Health.
Media Inquiries:
Shira Polan
Phone: 212-404-4279
shira.polan@nyulangone.org
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SOURCE NYU Grossman School of Medicine and NYU Langone
Health
