Air Pollution Penetrates Placenta, Gets To Fetus, Study Warns

Side effects of air pollution exposure during pregnancy may impact an unborn fetus, according to the findings of new research that suggests the toxic particles can pass through the placenta and reach the developing child. 

In a study presented at the European Respiratory Society International Congress, researchers indicate that small particles of air pollution are able to move from the lungs and cross the placenta during pregnancy, potentially putting the unborn baby at risk of side effects. The findings are considered preliminary until published in a peer reviewed journal.

Researchers studied the placentas of five pregnant women living in polluted London. They were all scheduled for cesarean section deliveries at the Royal London Hospital. Each woman was a non-smoker with uncomplicated pregnancies and gave birth to a healthy baby. The women gave permission to researchers to study the placenta after delivery.

The team honed in on findings from prior studies indicating the effects of pollution were harmful to the unborn baby. Prior research indicates air pollution exposure before birth affects the child’s emotions and behavior and increases the risk of the fetus being stillborn. Thus, researchers wanted to see if the air pollution particles passed from the mother’s lungs to the placenta, potentially causing serious side effects.

Researchers studied placental macrophages. Macrophages are in different parts of the body and are part of the immune system. They envelop harmful particles, like bacteria or pollution. In the placenta, they work to help protect the fetus.

More than 3,500 placental macrophages from the five placentas were studied under powerful microscopes. The same technique has been used to study macrophages in human airways and lungs.

Researchers found 60 cells that contained 72 small black areas that they believe were carbon particles, such as those that are produced by air pollution. On average each placenta contained five square micrometers of the black substance they believed was carbon.

The study suggests that the black areas are the first evidence that inhaled pollution particles move beyond the lungs and into the placenta.

Air pollution is a combination of small and large particles of dust, dirt, smoke, soot and liquid, many much smaller than a strand of human hair. The carbon particles are generated by burning fossil fuels, car exhaust, wild fires and other sources of pollution. They can enter the respiratory system and travel to the lungs.

Researchers indicate the particles are now found in the placentas of pregnant women. When pregnant women breathe polluted air, the particles reach the placenta through the bloodstream.

While the evidence indicates pollution affects the placenta, it’s not clear whether it can get directly to the fetus after getting to the placenta. Researchers believe its possible and that it doesn’t have to enter the baby’s body directly to have a negative effect since the placenta is the baby’s link to the mother.

Side effects of air pollution extend beyond pregnancy. Research indicates air pollution reduces the life expectancy of people worldwide and causes developmental problems to children’s brains.

Other research links pollution exposure during pregnancy to increased risk of preterm birth, low birth weight, accelerated aging in children, infant mortality, and childhood respiratory problems. This study is another piece of evidence in a long list indicating the harmful effects pollution has on both mother and child.