Cerebral palsy is one of the most common physical disabilities starting in childhood. It happens when the developing brain is damaged or does not form properly, most often before birth or shortly after. Parents who smoke or are exposed to smoke during pregnancy often ask whether this habit could raise the risk of cerebral palsy in their baby, or even double the chances.
Researchers have been studying many pregnancy risk factors that can affect brain development, such as maternal infections, air pollution, obesity, cardiovascular disease, and tobacco use. For example, a recent analysis of air pollution and pregnancy found links between prenatal exposure to fine particulate matter and poorer outcomes like lower birth weight and higher risk of conditions such as cerebral palsy in some epidemiologic studies, suggesting that environmental toxins can interfere with placental function and fetal brain development.https://medicalxpress.com/news/2025-12-air-pollution-pregnancy-varying-effects.html Other work has shown that maternal obesity and pre existing cardiovascular disease are associated with higher rates of neurodevelopmental disorders in children, again pointing to the important role of the in utero environment.https://www.endocrinologyadvisor.com/news/maternal-obesity-neurodevelopmental-disorders/https://academic.oup.com/hropen/article/2025/4/hoaf074/8342467
Smoking during pregnancy fits into this broader picture of prenatal risk. Cigarette smoke contains thousands of chemicals, including nicotine, carbon monoxide, and many toxic particles. These substances can reduce oxygen delivery to the fetus, damage blood vessels, and disturb normal growth. In pregnancy, smoking is already known to increase the risks of low birth weight, placental problems, preterm birth, and stillbirth. All of these complications are also known risk factors for brain injury in the fetus or newborn, which can later show up as cerebral palsy.
The specific question of whether maternal smoking can double cerebral palsy rates is more complicated than it first appears. Some older and more recent epidemiologic studies have reported that children of mothers who smoked during pregnancy have higher rates of cerebral palsy compared with children of non smokers, sometimes approaching a doubling of risk in certain subgroups or when combined with other complications. However, these studies face several challenges.
First, many women who smoke during pregnancy may also have other risk factors. They may be more likely to have poor nutrition, inadequate prenatal care, higher rates of infections, higher body mass index, or underlying health problems such as cardiovascular disease or mental health conditions. Research on maternal cardiovascular disease and obesity shows that these types of chronic conditions on their own are linked to slightly higher rates of neurodevelopmental problems in children.https://academic.oup.com/hropen/article/2025/4/hoaf074/8342467https://www.endocrinologyadvisor.com/news/maternal-obesity-neurodevelopmental-disorders/ If these factors are not fully accounted for, it may look as if smoking alone is responsible for a large increase in cerebral palsy, when in reality smoking is part of a broader pattern of risk.
Second, genetic and familial factors matter. Work in other neurodevelopmental conditions, such as attention deficit hyperactivity disorder, has shown that simple comparisons between smokers and non smokers can be misleading. A large meta analysis of maternal smoking and ADHD found that children of mothers who smoked during pregnancy were about 50 to 70 percent more likely to have ADHD than children of non smokers.https://www.adhdevidence.org/blog-tags/pregnancy Yet the authors of that review and other experts have pointed out that mothers who smoke are also more likely to have ADHD themselves, and can pass on genetic risks to their children independent of smoking. The lesson is that association does not automatically prove causation.
This same caution applies to cerebral palsy. To say that maternal smoking doubles the rate of cerebral palsy, we would need strong evidence that carefully separates the effect of smoking from all these other influences. Studies would have to adjust for preterm birth, low birth weight, infections, maternal obesity, cardiovascular disease, socioeconomic status, and genetic background. Many existing studies do not do this perfectly. As a result, it is difficult to give a precise number such as a twofold increase that applies to all pregnancies.
What can be said with more confidence is that smoking during pregnancy is part of a cluster of risk factors that can make brain injury and cerebral palsy more likely. Smoking raises the chance of preterm birth, and prematurity is one of the clearest and strongest risk factors for cerebral palsy because very early babies are more vulnerable to brain bleeding and white matter injury. Large cohort studies in preterm infants show that complications like intraventricular hemorrhage are tied to later developmental and school problems, emphasizing how fragile the preterm brain is.https://pmc.ncbi.nlm.nih.gov/articles/PMC12699354/ By increasing the frequency of prematurity and low birth weight, maternal smoking likely increases the population burden of cerebral palsy indirectly, even if the exact size of that increase varies between groups.
It is also important to remember that cerebral palsy can arise even when the pregnancy seems healthy. Some cases are linked to genetic mutations, others to unknown prenatal events or unavoidable complications at birth. At the same time, many babies born to mothers who smoke will not develop cerebral palsy. Risk is about changing probabilities, not certainties, and doubling a rare risk still leaves the absolute chance relatively low. That said, any factor that pushes the odds upward, especially one that is preventable, deserves serious attention.
When clinicians and public health experts talk to parents, they usually avoid dramatic claims like smoking will double your baby’s risk of cerebral palsy, because the science does not support a single universal number. Instead, they focus on clearer messages:
Smoking in pregnancy harms the placenta and reduces oxygen to the baby.
Smoking increases preterm birth, low birth weight, and other complications that are known to raise cerebral palsy risk.
Quitting before
