Which substance is associated with a 1.8 to 2.8 greater risk of stillbirth?

The association of tobacco with a significantly increased risk of stillbirth can be attributed to the harmful effects of the various chemicals present in tobacco smoke. When a pregnant individual smokes, these toxins can enter the bloodstream and adversely affect the fetus. This exposure can lead to complications such as placental abruption, reduced blood flow, and oxygen supply to the fetus, all of which contribute to increased risks of stillbirth.

Studies have consistently demonstrated that tobacco use during pregnancy is linked to a heightened risk of poor outcomes, including low birth weight, preterm birth, and stillbirth. The risk factors are particularly pronounced when tobacco use is combined with other risk behaviors or environmental factors, further elevating the danger to fetal health.

In contrast, while alcohol, marijuana, and caffeine can also have adverse effects during pregnancy and may pose risks to fetal development, the specific association with stillbirth is most strongly documented with tobacco usage. Therefore, identifying tobacco as the substance with the most substantial correlation to stillbirth risk is well-supported by research in perinatal health.