Placental infection appears to increase the risk of cerebral palsy, but usually in an indirect way. It does this by triggering inflammation and complications such as preterm birth, oxygen shortage, or direct brain infection in the baby, all of which are known risk factors for cerebral palsy.[1][3][5]
To understand this better, it helps to look at three steps: what placental infection is, how it affects the baby, and how that connects to cerebral palsy.
Placental infection usually refers to infection and inflammation of the membranes and tissues around the baby, most often called chorioamnionitis or intra amniotic infection. In chorioamnionitis, bacteria or other germs ascend from the vagina into the uterus and infect the amniotic fluid, membranes, and often the placenta. Medical reviews of intrauterine and intra amniotic infection describe how these infections are closely linked with preterm labor and premature rupture of membranes, mainly because the inflammatory process makes the uterus more likely to contract and the membranes more likely to break early.[2] Researchers have found that high levels of inflammatory markers such as interleukin 6 and procalcitonin in mothers with intra amniotic infection are associated with preterm birth and with histologic chorioamnionitis identified in the placenta after delivery.[2]
When the placenta and membranes are infected, the baby is exposed to several harmful conditions at once.
First, infection and inflammation can destabilize the placenta’s normal function. The placenta is the baby’s supply line for oxygen and nutrients. Obstetric and birth injury sources note that placental problems, including placental abruption and placental insufficiency, can limit blood and oxygen flow to the baby’s brain and contribute to hypoxic or ischemic brain damage, which can lead to cerebral palsy.[1][3][7] While these sources often emphasize structural complications like abruption, infection can worsen placental function in a similar way by damaging tissues and altering blood flow.
Second, intrauterine and placental infections strongly increase the risk of preterm birth. Studies of intra amniotic infection show that women with laboratory evidence of infection are much more likely to deliver prematurely, and that inflammatory markers are useful to predict impending preterm delivery.[2] Being born preterm is one of the most consistent and well documented risk factors for cerebral palsy. Clinical summaries on cerebral palsy risk stress that premature birth and low birth weight greatly increase the likelihood of CP, and that a large share of cases begin during pregnancy in the context of such complications.[3][4]
Third, infections in or around the placenta can spread to the baby, causing fetal or neonatal infection. Maternal and fetal infections are repeatedly listed among important causes of brain injury that can result in cerebral palsy. Educational and legal medical sites explain that infections such as chorioamnionitis, meningitis, encephalitis, cytomegalovirus, and other bacterial or viral infections may cause inflammation in the developing brain or lead to neonatal sepsis, both of which raise the risk of cerebral palsy.[1][3][5] Maternal fever or untreated infections, including cytomegalovirus, German measles, Zika virus, herpes, syphilis, urinary tract infections, and toxoplasmosis, are cited as prenatal factors that can increase CP risk.[5]
Inflammation is a key link. When placental or intrauterine infection occurs, the mother and baby can mount a strong inflammatory response. This may include high levels of cytokines such as interleukin 6 in the amniotic fluid and in maternal blood.[2] Inflammatory mediators can cross to the fetus and may damage vulnerable areas of the brain, particularly in preterm infants whose white matter is still developing. This pathway, sometimes described as inflammatory or infectious brain injury, is distinct from but often combined with oxygen deprivation. Both routes are recognized contributors to cerebral palsy.
In many real world cases, these factors do not act alone. A pregnancy complicated by chorioamnionitis may also involve premature rupture of membranes, prolonged labor, fetal distress from reduced oxygen, and, after birth, problems like sepsis or untreated jaundice. Each problem adds to the overall risk. Guidance resources describe how combinations of prematurity, placental problems, infection, and events around delivery can all converge into the brain injuries associated with cerebral palsy.[1][3][4][5]
At the same time, placental infection does not guarantee that a child will develop cerebral palsy. Many babies exposed to chorioamnionitis or other intrauterine infections do not develop CP, especially if the infection is recognized quickly and managed appropriately. The infection is best understood as a risk factor that raises the odds, particularly by increasing preterm birth, fetal infection, and inflammatory brain injury. Reviews on cerebral palsy consistently emphasize that the condition has multiple possible causes and that in many children more than one risk factor is present.[3][4][8]
Because of this, prenatal care focuses heavily on preventing, detecting, and treating infections. Recommendations include early evaluation of maternal fever, screening for sexually transmitted infections, careful monitoring of premature rupture of membranes, and timely use of antibiotics when intra amniotic infection is suspected. Legal and medical sources that discuss preventable causes of cerebral palsy point out that failure to diagnose or treat maternal and placental infections, or failure to respond to resulting fetal distress, can contribute to avoidable brain injury.[1][5][7]
In summary, current evidence and expert summaries agree that infection involving the placenta and surrounding membranes is associated with a higher risk of cerebral palsy, mainly through increased preterm birth, impaired placental function, and direct infectious or inflammatory injury to the baby’s brain.[1][2][3][4][5] It is one important piece in a larger picture of prenatal and perinatal risk factors that together determine a child’s likelihood of developing cerebral palsy.[3][4][8]
Sources
https://www.nationalbirthinjurylaw.com/what-causes-cerebral-palsy
https://pmc.ncbi.nlm.nih.gov/articles/PMC12735148/
https://www.cerebralpalsyguide.com/cerebral-palsy/statistics/
