Predictive models of individual risk of elective caesarean section complications: a systematic review.

INTRODUCTION: With increasing caesarean section (c-section) rates, personalized communication of risk has become paramount. A reliable tool to predict complications would support evidence-based discussions around planned mode of birth. This systematic review aimed to identify, synthesize and quality appraise prognostic models of maternal complications of elective c-section. METHODS: MEDLINE, Embase, Web of Science, CINAHL and the Cochrane Library were searched on 27 January using terms relating to 'c-section', 'prognostic models' and complications such as 'infection'. Any study developing and/or validating a prognostic model for a maternal complication of elective c-section in the English language after January 1995 was selected for analysis. Data were extracted using a predetermined checklist: source of data; participants; outcome to be predicted; candidate predictors; sample size; missing data; model development; model performance; model evaluation; results; and interpretation. Quality was assessed using the Prediction model Risk Of Bias ASsessment Tool (PROBAST) tool. RESULTS: In total, 7752 studies were identified; of these, 16 full papers were reviewed and three eligible studies were identified, containing three prognostic models derived from hospitals in Japan, South Africa and the UK. The models predicted risk of blood transfusion, spinal hypotension and postpartum haemorrhage. The study authors deemed their studies to be exploratory, exploratory and confirmatory, respectively. From the three studies, a total of 29 unique candidate predictors were identified, with 15 predictors in the final models. Maternal age (n = 3), previous c-section (n = 2), placenta praevia (n = 2) and pre-operative haemoglobin (n = 2) were found to be common predictors amongst the included studies. None of the studies were externally validated and all had a high risk of bias due to the analysis technique used. CONCLUSION: Few models have been developed to predict complications of elective c-section. Existing models predicting blood transfusion, spinal hypotension and postpartum haemorrhage cannot be recommended for clinical practice. Future research should focus on identifying predictors known before surgery and validating the resulting models.

Long-term effects of gestational diabetes on bone mineral density and fracture risk: Analysis of the Norfolk cohort of the European Prospective Investigation into Cancer (EPIC-Norfolk) population-based study.

OBJECTIVES: Gestational diabetes mellitus (GDM) is a common pregnancy complication. This study aims to investigate the association between a history of GDM and bone mineral density (BMD), fractures, and falls in later life. STUDY DESIGN: We used data from the Norfolk cohort of the European Prospective Investigation into Cancer (EPIC-Norfolk) where BMD at calcaneum was measured at second health check (1997-2000) using broadband ultrasound attenuation (BUA) and velocity of sound (VOS) in 7,515 women. Fractures and falls were documented from hospital admissions data via linkage with ENCORE (East Norfolk Commission Record) and history of GDM from health questionnaires at baseline. We examined the relationship between GDM and BUA/VOS using linear regression. Cox regression was used to estimate hazard ratios (HRs) for incident fractures and falls, controlling for age, BMI, smoking status, physical activity, area deprivation, self-reported stroke, use of diuretics, calcium and vitamin D supplements, social class and education, statin and total blood cholesterol, prevalent diabetes, hormone therapy and menopausal status. RESULTS: History of GDM (n = 183) was not statistically significantly associated with BUA/VOS in fully adjusted linear regression models with unstandardised beta coefficients (standard error): -0.37 (1.40) and -5.41 (3.48). GDM was significantly (p < 0.05) associated with risk of hip and all fractures, fully adjusted HRs(95 %CI) 2.46(1.54-3.92) and 1.60(1.09-2.35), respectively. Median follow-up from first live birth to date of admission was 53 and 52 years, respectively. CONCLUSION: There was an association between history of GDM and risk of any fracture as well as hip fracture specifically. Further research is required to confirm this.