Data abstraction
Data of eligible patients were reviewed and abstracted using a standardized spreadsheet that comprise patient baseline information(e.g. age, parity, body mass index “BMI”, ethnicity, smoking status), obstetric and gynaecologic data (e.g. obstetric complications, previous CS, prior gynaecologic surgeries), medical history, antepartum and intrapartum disease characteristics (e.g. PAS type, complete versus focal uterine wall invasion, bladder invasion, parametrial invasion, placental location), diagnosis (antepartum versus intrapartum diagnosis, imaging modality, and gestational age at diagnosis), antepartum haemoglobin level, intraoperative details(e.g. hysterectomy versus uterine preservation, uterus preserving procedures used either surgical or IR-related, success of uterine preservation, use of preoperative or intraoperative sonographic assessment, type of uterine incision and its relation to the placenta, intraoperative blood loss, transfused blood products, surgical complications), maternal outcomes (success of uterine preservation, length of hospital stay, admission to intensive care unit [ICU], postoperative complications), and neonatal outcomes. Data collection was completed on June 15th, 2020.
Study Outcomes
Primary outcome of the study was massive PAS-associated blood loss. This indicates intraoperative blood loss equal to or greater than 2500 ml, blood loss necessitating massive blood transfusion (defined as transfusion of at least 10 units of packed red blood cells [RBCs] within 24 hours) or disseminated intravascular coagulopathy (DIC) secondary to intraoperative blood loss. Statistical analysis Continuous variables were described in means and standard deviations/medians and interquartile ranges (IQR), and categorical variables were summarized in numbers and percentages. Shapiro-wilk test was used to test normality of distribution; parametric variables were compared using student’s t test while non-parametric variables were tested using Mann-Whitney U test. Logistic regression was used to test association between the primary independent variable (uterus preservation vs. caesarean hysterectomy), with adjustment for potential confounders, and outcomes (massive PAS-associated blood loss and admission to ICU). Each independent variable was first tested using univariable logistic regression and results were expressed in unadjusted odds ratio (OR) and 95% confidence interval (CI). Variables which yielded p-values of less than 0.2 in univariable logistic regression were included in the final multivariable logistic regression model. Results were presented as adjusted ORs (aORs) and 95% CIs. Statistical analysis was conducted using STATA 16 software (StataCorp, College Station, TX).