From NAMIs Website

Electroconvulsive Therapy (ECT)

When used in women who are pregnant, ECT may pose fewer risks than untreated mood episodes or treatment with medications known to be harmful to fetuses. Complications of ECT during pregnancy are uncommon. Monitoring heart rate and oxygen levels of the fetus during ECT can detect most problems, and medications are available to correct difficulties. Though some birth defects, developmental delays, or mental retardation have been described in the children of women who underwent ECT while pregnant, there is not a number or pattern to these reports that suggests a relationship to ECT. It is very important for pregnant women who undergo ECT to stay nourished and hydrated to help prevent premature contractions. Intubation or antacids may also be used to decrease the risk of gastric regurgitation or lung inflammation during anesthesia for ECT.