BackgroundStillbirth, defined as death of a fetus in utero after 20 weeks of gestation, occurs in 1 to 2% of pregnancies in the United States. Many of these stillborn infants have associated malformations, including chromosome abnormalities, neural tube defects, and malformation syndromes. Other causes are abnormalities of the placenta and maternal conditions, such as pre‐eclampsia and obesity. A consecutive sample of malformed stillborn infants can establish the relative frequency and severity of the associated malformations.MethodsStillbirths were identified in the Active Malformations Surveillance Program at Brigham and Women's Hospital (1972–2012). The findings at autopsy, including the findings in the placenta and the results of diagnostic studies, were compiled.ResultsOne hundred twenty‐seven stillborn infants with malformations were identified at autopsy among 289,365 pregnancies, including trisomies 21, 18, and 13; 45,X; triploidy; anencephaly; lower urinary tract obstruction; holoprosencephaly and severe heart defects, such as hypoplastic left heart syndrome and tetralogy of Fallot with pulmonary atresia. The severity of the abnormalities in stillborn infants was more severe than the spectrum of abnormalities identified in live‐born infants.ConclusionAn autopsy of the stillborn fetus, including chromosome microarray and an examination of the placenta, can identify the underlying causes of the stillbirth. This review of stillborn fetuses with malformations showed that several different lethal malformations and heart defects are more common than among live‐born infants. These postmortem examinations can improve the counseling of the parents about risks in future pregnancies. Birth Defects Research 110:114–121, 2018.© 2018 Wiley Periodicals, Inc.