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\begin{document}

\title{Development and Validation of a Prognostic Nomogram for Severe
Postpartum Haemorrhage After Caesarean Delivery: A Two-Centre
Retrospective Study}



\author[1]{Wanchang Yin}%
\author[1]{Xinghe Wang}%
\author[2]{Ruirui Li}%
\author[1]{Junhong Guo}%
\author[1]{Manna Sun}%
\author[3]{Shujing Yang}%
\author[2]{Dunjin Chen}%
\author[2]{fang he}%
\affil[1]{Dongguan Maternal and Child Health Care Hospital}%
\affil[2]{Affiliation not available}%
\affil[3]{The Third Affiliated Hospital of Guangzhou Medical University}%


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  \date{May 27, 2024}


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\begin{abstract}
Abstract Objective: To develop and validate a nomogram to predict severe
postpartum haemorrhage (PPH) following caesarean delivery. Design:
Two-centre retrospective cohort study. Setting: Third Affiliated
Hospital of Guangzhou Medical University and the Dongguan Maternal and
Child Health Care Hospital. Population: Cesarean delivery patients from
the Third Affiliated Hospital of Guangzhou Medical University were
divided into a development cohort (n=11,037) and an internal validation
cohort (n=4,673). Cesarean delivery patients from the Dongguan Maternal
and Child Health Care Hospital (n=13,775) were enrolled in the external
validation cohort. Methods: The nomogram was based on independent risk
factors for severe PPH obtained by multivariate logistic regression. We
evaluated the discrimination and calibration of the nomogram in the
development and validation cohorts. The area under the receiver
operating characteristic curve, the Hosmer-Lemeshow test, and
calibration plots were used to assess the nomogram. Main outcome
measures: Postpartum haemorrhage. Results: Severe PPH occurred in 4.5\%,
4.3\%, and 2.0\% of the patients in the development, internal
validation, and external validation cohorts, respectively. The nomogram
used data including previous caesarean delivery, low pre-pregnancy
weight, placenta previa, and placenta accreta spectrum disorders. The
area under the curves of the nomogram in the internal and external
validation cohorts were 0.915 (95\% confidence interval, 0.893--0.938)
and 0.799 (95\% confidence interval, 0.764--0.834), respectively.
Consistency between the predicted and actual probabilities was observed
in both validation cohorts. Conclusions: The nomogram displayed good
calibration and discrimination; thus, it can be used for screening and
timely intervention by clinicians, thereby reducing severe PPH
incidence.%
\end{abstract}%



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