Association between birth weight and massive haemorrhage in pregnancy with a low-lying placenta: a 9-year single-centre retrospective cohort study in Japan

Abstract

A low-lying placenta is a well-known cause of a massive intrapartum haemorrhage. We aimed to evaluate whether neonatal birth weight deviation from the nationwide average could predict a massive haemorrhage during a delivery in the women with a low-lying placenta. This study included 40 women. The main outcomes were a massive haemorrhage and a neonatal birth weight deviation. We used a receiver operating characteristic curve analysis to determine the optimal birth weight deviation cut-off for predicting a massive haemorrhage. A multiple logistic regression model was used to identify the variables significantly associated with a massive haemorrhage. The best cut-off for predicting a massive haemorrhage was a birth weight deviation of +0.51 standard deviations (SDs) from the nationwide average. A birth weight deviation of ≥ +0.51 SDs was significantly associated with an increased massive haemorrhage risk.

Impact statement

• What is already known on this subject? A low-lying placenta is a well-known cause of a massive intrapartum haemorrhage. Therefore, when managing pregnancies with a low-lying placenta, the possibility of severe perinatal bleeding should be considered, and it is desirable to determine reliable predictors of a haemorrhage. However, few studies have reported the predictive factors of a massive haemorrhage in patients with a low-lying placenta.

• What do the results of this study add? We demonstrated that a birth weight deviation from the nationwide average was significantly associated with a massive intrapartum haemorrhage in patients with a low-lying placenta. To our knowledge, this is the first study to clarify the association between a neonatal birth weight and a massive intrapartum haemorrhage incidence and to determine the optimal birth weight deviation cut-off for predicting a massive haemorrhage in patients with a low-lying placenta.

• What are the implications of these findings for clinical practice and/or further research? An accurate risk stratification using the foetal weight as a marker for a predicting massive intrapartum haemorrhage may help in the management of patients with a low-lying placenta. Studies with a larger sample size are required to confirm our findings.

Keywords:

• Low-lying placenta
• massive haemorrhage
• birth weight
• caesarean section
• placenta praevia
• risk factors

Acknowledgements

We thank the study participants for allowing us to use their personal data.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.