Secondhand Smoke and Pregnancy
Secondhand smoke exposure to an unborn child in its mother's womb can alter lung function and structure in the child and create other changes that are known to predispose children to long-term pulmonary risks. By breathing the air of a smoke-filled room, a pregnant woman exposes her unborn child to a variety of disease-causing chemicals, including the dangerous poisons arsenic and hydrogen cyanide, as well as formaldehyde, which is used in embalming fluid. Exposure to secondhand smoke during pregnancy can lead to a wide range of health problems for both the unborn child and the mother, including:

Still births
Premature birth
Birth/delivery difficulties
Low birth weight
Sudden infant death syndrome (SIDS)
Mental retardation
Childhood respiratory disorders
Learning and developmental problems
Cancer-causing agents in infants' blood

What Is Secondhand Smoke?
Secondhand smoke is a combination of the smoke in the air from a burning cigarette and the smoke exhaled by a person who is smoking. Secondhand smoke is the number one source of indoor air pollution and contains nearly 5,000 chemical compounds, including arsenic, a dangerous poison; formaldehyde, which is also used in embalming fluid; and hydrogen cyanide, another toxic poison. Like asbestos, secondhand smoke has been classified as a "Class A" carcinogen, or cancer-causing substance, by the U.S. Environmental Protection Agency. Only 13 other substances are considered as dangerous to human health.

Secondhand smoke kills 53,000 nonsmokers nationally each year, and is known to cause the following illnesses:
Lung cancer
Heart disease
Nasal sinus cancer
Respiratory disease
Bronchitis
Middle ear infections
Asthma
Pneumonia