Tiny pieces of plastic have been found in the placenta, blood, breastmilk, and even a newborn’s first stool, which means babies might be exposed to plastic pollution before they’re born — and that could be a health concern.

What we've found so far suggests that microplastics may be present in the bodies of newborns and breastfeeding mothers. Our analysis of the available research shows that tiny pieces of plastic have been detected in the placenta, breastmilk, and meconium—the newborn’s first stool—indicating possible exposure before birth and during early life [1]. We reviewed one assertion based on current findings, and it supports the idea that microplastics can cross into spaces connected to fetal and infant development [1]. The presence of these particles in the placenta suggests they might move from the mother’s body to the developing baby. Finding microplastics in meconium, which forms before birth, adds to the evidence that exposure could begin in the womb. Similarly, their detection in breastmilk raises questions about whether breastfeeding could be another route of early-life exposure [1]. Our current analysis does not include any studies that refute this possibility. However, we only have limited evidence so far—just one assertion based on observational findings. We cannot determine how often this occurs, what the sources are, or what health effects—if any—might result from this exposure. Because the evidence is still so limited, we can’t say for sure how common or significant this exposure is. But what we’ve seen so far leans toward the possibility that microplastics reach babies before and just after birth. Practical takeaway: While we don’t yet know the health impact, the presence of microplastics in the placenta, newborn stool, and breastmilk suggests that plastic pollution may begin affecting us very early in life.