Case-control study of risk factors for obstetric patients' admission to intensive care units

Objective: To identify risk factors among pregnant and newly delivered women to be treated in intensive care unit (ICU). Study design: A case-control survey of pregnant women or delivered within the past 42 days admitted to ICU was performed in three regions of France. Two controls by subject were matched for hospital and outcome (vaginal delivery, caesarean section, abortion or ectopic pregnancy). Bivariate and multivariate analyses, using different models were done. The confidence intervals (CI) are 95% intervals. The odds ratio (OR) were adjusted on matching factors in univariate analysis, and adjusted on all factors included in the multivariate analysis. Results: 375 subjects treated in ICU and 750 controls were included in the study. These women did not differ in age, marital status or social class, but the cases were more often of non-European nationality. They had more often medical antecedents which were also more serious. The subjects consulted at the maternity facility less frequently than did controls. The following variables increased the risk of ICU admission: no antenatal consultation at the maternity ward (OR 2.8, CI 1.5–5.1) serious past medical history (OR 2.7, CI 2.0–3.6), non-European nationality (OR 2.5, CI 1.7–3.7) and current multiple pregnancy (OR 2.3, CI 1.2–4.5). Conclusion: As some factors can clearly be ascertained before the condition of the patient worsens it is argued that more attention could be paid to them. Regarding the risk associated to multiple pregnancy, further efforts to prevent them ought to be considered.