Perinatal mortality after previous cesarean section

Background: Perinatal neonatal mortality is increased where there is a maternal history of cesarean section (0.45 vs. 0.31 % in deliveries after previous vaginal delivery). In this study we have analyzed the causes of the perinatal deaths.

Methods: The increased risk was found by analyzing the database of the Swiss Working Group of Obstetric and Gynecological Institutions with its 29 046 deliveries with a history of previous cesarean section between 1983 and 1996. In this time period 130 perinatal neonatal deaths in deliveries after previous cesarean were recorded.

Results: The cause of death could be established in 124 cases. In the 42 term deliveries the causes of death were the following: malformations 20, uterine rupture 5, placental abruption 5, respiratory distress syndrome 5, and other causes 7. In the 82 preterm deliveries: prematurity caused by premature contractions/rupture of membranes 38, malformations 12, chorioamnionitis 12, placental abruption 9, severe growth retardation 4, complications of placenta praevia 2, uterine rupture 1, other causes 4.

Conclusions: Preterm deliveries are more frequent (in births) after a previous c/s (7.75 vs. 5.55 % in multiparous mothers without previous cesarean) - not because of a higher frequency of preterm labor or premature rupture of membranes, but because of placental abruption, chorioamnionitis, placental insufficiency and severe growth retardation. Although some of the neonatal deaths are linked to the previous cesarean delivery, perinatal death after previous cesarean is a very rare event. A recommendation to routinely perform a repeat cesarean instead of a trial of labor seems not appropriate.