A detailed review of laboratory records for equine abortion is fundamental in establishing current disease trends and suggesting problems important for further research. To review the causes of abortion and neonatal death in equine diagnostic submissions to the Animal Health Trust over a 10 year period. The diagnoses in 1252 equine fetuses and neonatal foals were reviewed and analysed into categories. Problems associated with the umbilical cord, comprising umbilical cord torsion and the long cord/cervical pole ischaemia disorder, were the most common diagnoses (38.8%: 35.7% umbilical cord torsion and 3.1% long cord/cervical pole ischaemia disorder). Other noninfective causes of abortion or neonatal death included twinning (6.0%), intrapartum stillbirth (13.7%) and placentitis, associated with infection (9.8%). E. coli and Streptococcus zooepidemicus were the most common bacteria isolated. Neonatal infections not associated with placentitis accounted for 3.2% of incidents; and infections with EHV-1 or EHV-4 for 6.5%. Definitive diagnosis of equine abortion is possible in the majority of cases where the whole fetus and placenta are submitted for examination. Given the high incidence of umbilical cord torsion and related problems as causes of abortion in UK broodmares, more research on factors determining umbilical cord length and risk of torsion is essential.