Placental Abruption and Perinatal Mortality: Abnormal Placentation and Spontaneous Abortion as Contributors to Left Truncation Bias.

ABSTRACT:

Background

Generally, studies in perinatal epidemiology restrict cohort entry to 20 weeks of gestation, but exposures and outcomes may occur earlier. This restriction may introduce left truncation bias.

Objectives

To examine the impact of left truncation bias when estimating the causal effect of abruption on perinatal mortality in the context of abnormal placentation, with spontaneous abortion (SAB) as a censoring event.

Methods

Through 80 Monte Carlo simulation scenarios based on realistic clinical assumptions, we estimated risk differences (RD), risk ratios (RR) and bias parameters for the abruption-perinatal mortality association.

Results

Censoring by SAB ranged from 5.6% to 7.6% across simulation setups. The risk of mortality was underestimated in observabl

SUBMITTER: Kinlaw AC 

PROVIDER: S-EPMC12353283 | biostudies-literature | 2025 Jun

REPOSITORIES: biostudies-literature