Exposures
Smoking is the most common exposure that has been
associated with fetal death. Although the vast majority
of women who smoke deliver liveborn infants, numerous
studies identify smoking as a risk factor for
fetal death. The risk is typically 1.5-fold over nonsmokers;
the risk decreases to background rate in
women who stop smoking after the first trimester. The
cause is uncertain but may involve an increase in fetal
carboxyhemoglobin and vascular resistance, causing
impaired growth and hypoxia. Smoking also increases
the risk for potentially catastrophic conditions
such as abruption.