Causes of stillbirth at different gestational ages in singleton pregnancies

To compare causes of stillbirth in preterm and term pregnancies.

Cohort study.

All delivery wards in Stockholm, 1998-2009.

Stillbirths from singleton pregnancies of gestational age ≥22(+0) (n = 1089) extracted from a web-based database including all stillbirths in the major Stockholm area since 1998.

The parents of the stillborns were all offered an extensive standardized investigation. The causes of death were assigned in a perinatal audit using the Stockholm classification of stillbirth. Singleton stillbirths were divided into preterm (gestational week 22(+0) -36(+6) ) and term/post-term (gestational week ≥37(+0) ). The term/post-term group was subdivided into term (gestational week 37(+0) -40(+6) ) and post-term stillbirths (gestational week ≥41(+0) ).

Causes of stillbirth at different gestational ages.

A higher proportion of placental abruption and preeclampsia/hypertension was seen in preterm stillbirths compared with term/post-term stillbirths, which instead had a higher proportion of umbilical cord complications and infection. Infection was more common in post-term than term stillbirths (46.5 vs. 19.8%, p < 0.001).

Increased knowledge of causes of stillbirth in different gestational ages may be valuable in developing strategies for prevention of fetal death. The high proportion of infection in post-term stillbirths could be clinically important and warrants further studies.