Sudden intrauterine unexplained death syndrome (SIUDS) is mainly caused by placental dysmaturity

Purpose: Several clinical risk factors of sudden intrauterine unexplained death syndrome (SIUDS) in late pregnancy have gained attention in the last years. The knowledge about the caused of SIUDS, determined by autopsy is limited.

Methods: Fetuses with clinically unexplained intrauterine death were obtained from the files of the Institute of Pathology, Dept. of Perinatal- & Gynecologic Pathology of the Univeristy of Leipzig to determine the causes of intrauterine death.

Results: Out of 51 cases twelve cases fulfilled the criteria of SIUDS >30th weeks of gestation without any known clinical risk factors for intrauterine death. The mean pregnancy age was 36.5 weeks, the mean maternal age 32.4 years. Two thirds of the fetuses represented with intrauterine growth restriction. Causative for intrauterine death was placental dysmaturity in 11/12 cases. One SIUD was caused by thin-cord-syndrome.

Conclusions: Chronic placental insuffience resulting in IUR is a main risk factor for SIUDS. Acute placental failure because of placental dysmaturity represents the main cause for SIUDS. Fetal autopsy and placental examination is strongly recommended in SIUDS.