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Development and validation of a new scoring system for the critically ill obstetric patient


Measuring physiological status prior to ICU admission could help refine prognosis after ICU discharge. The literature lacks such studies.


To determine the correlation between a New Simplified Acute Physiology Score designed for obstetric patients before their admission to the ICU and ICU mortality.


A prospective study, part of the Assessment of Prognosis and Risk of Mortality in Obstetrics (APRiMO) study. Seventeen physiologic and biologic parameters were measured, and pathological intervals shifted to fit physiologic changes related to pregnancy as described by Margaria [1] with a slight modification. An aggregate score included the worst value for each parameter during a maximum of 24 hours before admission to the ICU. Patients were devided into two datasets: development (n = 350) and validation (n = 191). Discrimination was assessed by the area under the receiver operator characteristic curve (AUROC). Calibration was assessed by Hosmer–Lemeshow (Pr) goodness-of-fit C statistics. After validation of the overall score, we tried to simplify it without altering its statistical power. Statistical analysis was computed on SPSS 11.5 XP-Windows compatible. P < 0.05 was considered significant. Results are expressed by mean ± standard deviation.


Patients were first managed in a tertiary care obstetric hospital, a referral center for high-risk pregnancies, with a level 3 neonatal ICU. Then they were transferred to our independant multidisciplinary ICU.

Study period

January 1996–December 2003.


All obstetric patients (n = 541) transferred to the ICU. Inclusion criteria: severe pre-eclampsia/eclampsia, HELLP syndrome, stroke, and so on.

Measurements and results

Obstetric complications accounted for 70% of admissions. Mean age was 31.2 ± 5.9 years, Mean term was 34.7 ± 4.5 weeks. The majority of our patients were admitted after delivery. The mortality rate was 10.4% (n = 57). In the development dataset, the SAPS-O discriminated (AUROC = 0.902) and calibrated (Pr = 0.524) well. The validation dataset also discriminated (AUROC = 0.904) and calibrated (Pr = 0.895) well (Fig. 1). A simplified model made with 7/17 parameters also discriminated and validated well with, respectively, AUROC and Pr in the same development and validation data of: AUROC 0.947 and 0.793; Pr 0.968 and 0.716.

Figure 1

Figure 1


SAPS-O is correlated to ICU prognosis. This could help adjust for lead-time bias, comparison between centers and management policies.


  1. 1.

    Margaria E, Collo E, Castelli I: Which patients must be admitted to the intensive care unit. In Anesthésie-Réanimation en obstétrique Edited by: Arnette JEPU. 1994.

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Haddad, Z., Kaddour, C., Chaaoua, T. et al. Development and validation of a new scoring system for the critically ill obstetric patient. Crit Care 9, P217 (2005).

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  • Receiver Operator Characteristic Curve
  • Simplify Acute Physiology Score
  • Acute Physiology Score
  • HELLP Syndrome
  • Aggregate Score