Recurrence of stillbirth and second trimester pregnancy loss.

The 3,003 women referred to the Wisconsin Stillbirth Service Program following a stillbirth or second trimester fetal death reported a total of 4,563 previous pregnancies including 180 previous second or third trimester losses for a total precurrence rate of 3.95%. The 142 women with a history of at least one previous stillbirth and/or late miscarriage differed significantly from the entire cohort with respect to timing and cause of their losses. Women experiencing multiple losses frequently had both second trimester miscarriages and stillbirths >20 weeks but did not have an increased risk of first trimester miscarriage. Recurrences were more likely to be in the second trimester (52% vs. 37%) and to have a maternal (20% vs. 11%) or placental (27% vs. 19%) cause. While fetal causes overall were less common in the group with recurrence (18% vs. 27%), the difference was due mainly to fewer common aneuploidies and other low recurrence risk conditions. Not only known recessive conditions but also "idiopathic hydrops" and multiple congenital anomalies not fitting a known syndrome were more frequent than expected, suggesting that these groups should be investigated for underlying genetic causes that might have been overlooked. Women with second trimester losses and/or a maternal or placental cause of death face significantly higher empiric risks (7-8% vs. 4% for the entire cohort) and should be counseled accordingly. Study of recurrent fetal loss can help identify high risk women who may benefit from treatment and preventive strategies in the future.