Strengths and limitations
Among the similar retrospective studies, to our knowledge, this study is
the largest cohort with 747 women who gives subsequent cesarean birth
with placenta previa after the first cesarean delivery, since this kind
of medical situation is rare in clinic, but, with life-threatening
consequences. These patients were from 13 hospitals located in the
different regions of China. Although these hospitals belong to the
first-class hospitals in China and represent the top level of local
medical care, the regional differences on medical care are existed among
these hospitals, which may cause the variation of the outcome occurrence
and treatment, and can be considered as flaw for the present study.
However, the obtained conclusions are still national representative.
Another key finding in our study is that the examination of ultrasound
combined with MRI largely improves the prediction of potential outcome
in the patients, which can used to follow up patients in order to
prevent and treat the potential severe complications. Finally, we also
demonstrate that vascular occlusion does not affect massive bleeding in
patients, which is disagree with the current opinion. But, we have to
point out that vascular occlusion in the current study is performed only
in 106 patients, among whom the different strategies for vascular
blocking is applied, which is another limitation for this study and more
cases and prospective study are needed to confirm our conclusion.