Prenatal Opioid Exposure Alters Sleep and Pain Perception
The opioid crisis started when doctors began prescribing too many painkillers. Opioids are strong pain relievers, but what happens when a baby is exposed to them before birth, while still in the womb? Could that change how the baby feels pain later in life?
To find out, researchers looked at the genes in babies who were exposed to opioids during pregnancy. They found important differences that might explain how these babies sense pain differently after they’re born.
The Study:
Title: Prenatal opioid exposure alters pain perception and increases long-term health risks in infants with neonatal opioid withdrawal syndrome
Published in Frontiers in Pain Research, April 16, 2025
Summary in Plain English :
What the Study Was About
This study looks at how being exposed to opioids before birth might change the way certain pain-related genes work. These changes could affect the long-term health of babies, especially those diagnosed with Neonatal Opioid Withdrawal Syndrome (NOWS).
Scientists studied the placentas of 96 babies, including:
Babies exposed to opioids in the womb who had NOWS and needed medicine to treat it
Babies exposed to opioids but did not need treatment for NOWS
Babies who were not exposed to opioids at all
They looked at the babies’ DNA “markers” in genes related to pain to see if there were lasting changes.
What They Found
Babies who are exposed to opioids before birth—especially those who go through withdrawal and need treatment—can have changes in the way their pain-related genes work. These changes, known as epigenetic changes, don’t change the genes themselves, but affect how the genes are turned “on” or “off.” In this case, the affected genes help control how the body senses and reacts to pain.
Because of these changes, some children may feel pain more strongly than others, a condition known as hyperalgesia. For example, a child might cry intensely or withdraw even from light touch, common daily bumps, or the feeling of clothes against their skin. On the flip side, other children may have a dulled response to pain. A scraped knee or bump on the head that would normally bring tears might barely get a reaction. Both extremes can make it harder for caregivers to understand when a child is hurting or when something might be wrong.
These differences in pain perception are likely tied to how the brain and nervous system develop in response to opioid exposure. While more research is needed to fully understand the long-term effects, what we do know is that these changes matter—not just in how kids experience physical pain, but also in how they might respond to stress, medical procedures, and emotional challenges. Recognizing this can help families, doctors, and teachers provide the right kind of care and support.
Just as prenatal opioid exposure can affect how a child experiences pain, it may also disrupt the body’s natural sleep-wake cycles. Researchers found changes in genes that help control the circadian rhythm—the internal clock that tells our bodies when to sleep, wake, and perform basic functions. These gene changes were especially strong in babies who had Neonatal Opioid Withdrawal Syndrome (NOWS), suggesting that opioid exposure in the womb might throw off a baby’s natural ability to develop healthy sleep patterns.
These disruptions can lead to sleep that’s too light, too short, or frequently interrupted. For some children, it may look like difficulty falling asleep, staying asleep, or waking often during the night—even well past infancy. Others may struggle with irregular sleep-wake cycles that affect mood, attention, and learning during the day. Since healthy sleep is closely tied to brain development and emotional regulation, understanding these sleep-related changes helps caregivers and professionals better support children exposed to opioids before birth.
Why This Matters
These gene changes don’t mean the child is destined to struggle—but they could make the child more likely to have chronic pain, sleep problems, or emotional challenges later in life.
It highlights why early monitoring, support, and therapies are so important for children born with prenatal opioid exposure—even if they don’t have severe symptoms right after birth.
Conclusion
The gene changes found in this study could help explain how opioid exposure affects pain, brain development, and other health issues in both babies and mothers with opioid use disorder. This new understanding might lead to better treatments and pain management, for both parts of the dyad.
Many thanks to the authors of this article: Radhakrishna Uppala , Radhakrishnan Rupa , Uppala Lavanya V. , Trivedi Tithi S. , Prajapati Jignesh , Rawal Rakesh M. , Muvvala Srinivas B. , Bahado-Singh Ray O. , Sadhasivam Senthilkumar
