Vasa previa and placenta associated complications: Diagnosis and risk assessment

This thesis focused on vasa previa and pregnancy complications associated with abnormalities of the placenta.
Vasa previa on ultrasound was first reported in 1987 and has received increasingly attention over the last decades. Since the incidence of vasa previa is relatively low, literature on this complication is mostly limited to case reports, case series and reviews. The majority of the studies emphasize the importance of prenatal diagnosis because of the potential fatal neonatal outcome in pregnancies complicated by vasa previa. In many countries including the Netherlands, clear guidelines regarding prenatal diagnosis for vasa previa were unavailable. Therefore, in the first part of this thesis we focused on vasa previa. We evaluated the diagnostic accuracy of ultrasound in the prenatal detection of vasa previa and we investigated the incidence of and identified potential risk indicators for vasa previa. As a final step we initiated the implementation of a national guideline regarding prenatal screening and management in vasa previa.
As vasa previa, other abnormalities of the placenta such as placenta previa, placental abruption and retained placenta also have been associated with adverse maternal and neonatal outcomes. Placenta previa is a condition commonly seen during pregnancy, but the clinical presentation varies between asymptomatic and substantial vaginal blood loss, impeding the efficacy of an uniform guideline. The second part of this thesis aimed to differentiate between high-risk and low-risk women with placenta previa, providing opportunities for individualized antenatal management. Furthermore, we investigated the consequences of placental abruption and retained placental tissue with or without postpartum hemorrhage on a subsequent pregnancy to increase individualized prenatal care.