Published cohort studies, case series, and case reports over several decades of trazodone use in pregnant women have not identified a clear pattern of drug-associated major birth defects, miscarriage, or adverse maternal/fetal outcomes, according to current FDA labeling — though available human data remains more limited than for some other medications.
Animal studies showed some adverse fetal effects at doses many times higher than typical human doses (on a body-surface-area basis), which is a standard part of any drug's safety data package but doesn't translate directly to human risk at normal doses.
Decisions about continuing, starting, or stopping trazodone during pregnancy should always be individualized, weighing the risks of untreated depression or severe insomnia against any medication-related considerations, in conversation with your prescriber and obstetric team.