Background Women with pregnancies with suspected fetal anomalies are routinely referred to fetal medicine units for management. Some of these pregnancies end in spontaneous fetal loss or termination of pregnancy.

Objective We sought to determine the accuracy of antenatal detection of lethal fetal structural abnormalities by ultrasound following fetal loss evaluated by fetal postmortem.

Study design We retrospectively reviewed registry data of consecutive fetal autopsies, before 24 weeks gestation, performed in a regional perinatal pathology service in South Yorkshire England over a 5 year period comparing the postmortem findings to the antenatal diagnosis made in the regional fetal medicine unit which informed parental decisions. A subset of women who had antenatal care locally has been analysed.

Results There were 81 fetal postmortems of which 32% of the anomalies were diagnosed in the first trimester and 68% in the second trimester. Ninety-eight per cent were full postmortems. There was full agreement between antenatal and post-mortem findings in 86% of the cases. There was partial or major disagreement in 9% and 5% of the cases respectively. With the major disagreements, the post-mortem findings could result in modification of the postnatal counselling for recurrence and management of subsequent pregnancies.

Conclusion Antenatal ultrasound detected 86% of the fetal abnormalities for which parents opted for pregnancy termination or which led to spontaneous miscarriage. Postmortems not only provide reassurance of the antenatal diagnosis but also modify the management of future pregnancies.