To forecast the effect of rising primary and secondary cesarean rates on annual incidence of placenta previa, placenta accreta, and maternal mortality in future years.
A model was built using TreeAge Pro software to estimate the annual incidence of placenta previa, placenta accreta, and maternal mortality using existing data on national birthing order trends and cesarean and VBAC rates in recent years. Baseline assumptions were derived from the literature, including the likelihood of previa and accreta among women with multiple previous cesarean deliveries, and the likelihood of maternal mortality and cesarean hysterectomy in the setting of a previa or accreta. A 2-year inter-pregnancy interval and an annual birth rate of 4,000,000 were used in the model′s creation.
The model was calibrated to 2004 data and used to forecast previas, accretas, and maternal mortality in 2010, 2015, and 2020 under scenarios in which the cesarean rate increases further, remains stable, and decreases.
If primary and secondary cesarean rates continue to rise as they have in recent years, by 2020 the cesarean delivery rate will be 46.2% and there will be an additional 3728 placenta previas, 2524 placenta accretas, and 52 maternal deaths annually. Furthermore, the rise in these complications will lag behind the rise in cesareans by approximately 6 years.
If primary cesarean and VBAC rates remain unchanged from 2004 onward, the rate of previas, accretas, and maternal mortality will reach a steady state by the year 2010.
If primary and secondary cesarean rates continue to increase at their current rate, the annual incidence of placenta previa, placenta accreta, and maternal death will also rise substantially in the future. The full effect of increasing cesarean rates on these complications is seen approximately 6 years later.
1Increases in placenta previa, placenta accreta, and maternal death accompanying a rising cesarean rate
© 2008 Mosby, Inc. Published by Elsevier Inc. All rights reserved.