Clinical profile and outcomes of critically ill obstetric patients in the intensive care unit of a tertiary care center

Abstract

BACKGROUND

Although obstetric patients account for only 1%-2% of general intensive care unit (ICU) admissions, they constitute a distinct population with unique physiological characteristics and risk profiles. Therefore, understanding the clinical profile of these patients is essential for their appropriate management.

AIM

To evaluate clinical characteristics, outcomes, and mortality predictors among obstetric patients admitted to a multidisciplinary ICU, and to assess the performance of established severity scoring systems in this unique population.

METHODS

We conducted a retrospective study of all obstetric patients (pregnant or ≤ 6 weeks postpartum) admitted to the ICU of a tertiary care teaching hospital from January 2020 to April 2022. Primary outcomes included mortality rates and length of stay. Secondary outcomes included evaluation of Acute Physiology and Chronic Health Evaluation II, Sequential Organ Failure Assessment, Simplified Acute Physiology Score II, and Modified Early Obstetric Warning Score systems for mortality prediction.

RESULTS

During the research period, 101 patients were admitted to the ICU. The documented mortality rate was 27.7% among these patients admitted to the ICU. The predominant reason for ICU hospitalization was hypertensive disorders of pregnancy (20.7%), followed by postpartum hemorrhage (19.8%). Mechanical ventilation was necessitated in 67.3% of parturient. Cesarean delivery was the most common mode of delivery (58.4%). Fetal outcomes included 81.1% live births, 12.8% intrauterine deaths, and 2.9% stillbirths. Acute Physiology and Chronic Health Evaluation II, Simplified Acute Physiology Score II, Modified Early Obstetric Warning Score, and Sequential Organ Failure Assessment scores of 21 (14-26.5), 36 (28.7-43), 6 (4-7), and 5 (4-6) significantly predicted mortality (P < 0.05) in non-survivors.

CONCLUSION

Parturient may present to the critical care unit with hypertensive disorders, hemorrhage, morbidly adherent placenta, and other non-obstetric causes demanding obstetric and critical care. The availability of a dedicated obstetric critical care unit with specialized personnel would help decrease the mortality in this subset of patients.

Key Words: Maternal mortality; Obstetric intensive care; Critical care; Pregnancy complications; Severity scoring; Intensive care unit

Core Tip: Critically ill obstetric patients admitted to a tertiary care intensive care unit demonstrated a high mortality rate, with hypertensive disorders of pregnancy and obstetric hemorrhage being the leading causes of intensive care unit admission and death. Severity scoring systems were found to be effective in predicting patient outcomes, emphasizing their usefulness in early risk stratification and clinical decision-making. These findings highlight the importance of timely referral, early recognition of complications, and the establishment of dedicated obstetric critical care services to improve maternal outcomes.

INTRODUCTION

The United Nations Sustainable Development Goals set a global target to reduce the maternal mortality ratio to less than 70 deaths per 100000 live births by 2030. The maternal mortality ratio in India decreased by around 70%, from 398 per 100000 live births [95% confidence interval (CI): 378-417] in 1997-1998 to 99 per 100000 (90-108) in 2020, indicating significant progress still to be made to achieve the target by 2030[1]. The primary causes of maternal mortality found were obstetric hemorrhage (47%; more prevalent in economically underprivileged areas), pregnancy-related infections (12%), and hypertensive disorders of pregnancy (7%)[1]. Pregnancy-induced physiological changes predispose individuals to the exacerbation of pre-existing comorbidities or may result in conditions particular to pregnant patients, such as preeclampsia/eclampsia, thromboembolic diseases, peripartum/postpartum hemorrhage, and puerperal sepsis.

A trend towards increasing maternal age because of advances in reproductive technology, women’s empowerment, and late conceptions has increased the incidence of cesarean delivery, gestational diabetes, placenta previa, obstetric hemorrhage, and hypertensive disorders in pregnancy, pointing to a need for separate obstetric critical care units for better understanding and management of parturient[2].

Although obstetric patients account for only 1%-2% of general intensive care unit (ICU) admissions, they represent a distinct population with unique physiological characteristics and risk profiles; hence, it is imperative to understand their clinical profiles for proper management. Given that the assessment of obstetric admissions to the ICU is a significant method for monitoring critically ill women during pregnancy in a tertiary care setting, this study was undertaken to analyze the incidence, clinical characteristics, and outcomes of obstetric patients requiring admission to the multidisciplinary ICU of a tertiary care teaching hospital. The secondary aim of the study was to evaluate Acute Physiology and Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA), Simplified Acute Physiology Score II (SAPS II), and Modified Early Obstetric Warning Score (MEOWS) for predicting mortality in obstetric patients.

MATERIALS AND METHODS

Study design

This retrospective study was conducted on obstetric patients admitted to the critical care unit of a tertiary care hospital, with institutional ethics committee approval. The study adhered to the Strengthening the Reporting of Observational studies in Epidemiology guidelines. The study included all obstetric admissions (pregnant or within 6 weeks postpartum) requiring ICU care from January 2020 to April 2022. The patients’ files and nursing records were examined for information on age, gravida, parity, gestational age, comorbidities, medical disorders associated with pregnancy, reason for ICU admission, parturient status on ICU admission, complications in the ICU, and interventions performed. The severity of the disease was determined by admission day APACHE II, SAPS II, MEOWS, and SOFA scores. Adverse fetal outcomes were defined as intrauterine death or stillbirth occurring during the index pregnancy.

Statistical analysis

The data were compiled and analyzed using SPSS version 22. Results are presented as mean ± SD for quantitative variables with a normal distribution, and as median (interquartile range) for those with a non-normal distribution. Kolmogrov-Smirnopv test was done to assess for normality. Categorical variables are expressed as absolute numbers or percentages. The χ² test was used to compare categorical variables, and the student’s t-test was used to compare continuous variables. The Mann-Whitney test was implemented to evaluate quantitative data that did not show a normal distribution and ordinal variables. The multiple logistic regression method was implemented whenever relevant, and a P-value of less than 0.05 was considered statistically significant. The discriminative ability of severity scoring systems was assessed using receiver operating characteristic curve analysis, with area under the curve values interpreted as: 0.5-0.6 (poor), 0.6-0.7 (fair), 0.7-0.8 (good), 0.8-0.9 (very good), and > 0.9 (excellent).

RESULTS

During the research period, 101 eligible patients were admitted. The average age of parturient admitted to the ICU was 27.84 ± 5.2 years. The most common time for ICU admission was during the postpartum period (73.2%), followed by the third trimester (13.8%). The number of booked cases was 95 out of 101 (95%), and the majority of the patients admitted were multigravida (73.2%). The incidence of twin pregnancy was 1.98%.

The most common diagnosis for ICU hospitalization was hypertensive disorders of pregnancy (20.7%), followed by postpartum hemorrhage (19.8%; Table 1). Non-obstetric causes of admission are summarized in Table 2. Hemodynamic instability was the most common indication for ICU admission (39.6%), followed by respiratory distress (17.8%) (Table 3).

Table 1 Demographics and indications of intensive care unit admission of obstetric patients (n = 101), mean ± SD/n (%).

Variable
Age	27.84 ± 5.2
Comorbidities	23 (22.8)
Heart disease	13 (56.5)
Gestational diabetes	5 (21.7)
Hypertension	5 (21.7)
Antenatal checkup
Booked	96 (95.04)
Un booked	5 (4.95)
Gravida
Primigravida	27 (26.7)
Multigravida	74 (73.2)
Time of admission
First trimester	7 (6.9)
Second trimester	6 (5.9)
Third trimester	14 (13.8)
Postpartum	74 (73.2)
Twin pregnancy	2 (1.98)
Mode of delivery
Cesarean section	59 (58.4)
Normal delivery	30 (29.7)
Abortion	8 (7.9)
Laparotomy	4 (3.9)
Fetal outcome
Live	82 (81.1)
IUD	13 (12.8)
Still birth	3 (2.9)
Ectopic	3 (2.9)
Indications of ICU admission
Hypertensive disorder of pregnancy	21 (20.7)
Pre-eclampsia	6 (5.9)
Eclampsia	12 (11.8)
HELPP	3 (2.9)
PPH	20 (19.8)
Heart disease	13 (12.8)
Puerperal sepsis	5 (4.9)
Ectopic pregnancy	3 (2.9)

IUD: Intrauterine device; ICU: Intensive care unit; HELPP: Hemolysis, elevated liver enzymes and low platelets; PPH: Postpartum hemorrhage.

Table 2 Non-obstetric causes of admission to the intensive care unit.

Indication for ICU admission	n (%)
CAP	9 (8.9)
Sepsis	7 (6.9)
AKI	5 (4.9)
Pancreatitis	4 (3.9)
Stroke	4 (3.9)
Encephalopathy	3 (2.9)
Encephalitis	1 (0.9)
PRES	2 (1.9)
SAH	2 (1.9)
Trauma	1 (0.9)
Tuberculoma	1 (0.9)

ICU: Intensive care unit; CAP: Community-acquired pneumonia; AKI: Acute kidney injury; PRES: Posterior reversible encephalopathy syndrome; SAH: Subarachnoid hemorrhage.

Table 3 Indications for intensive care unit admission.

Indication	n (%)
Hemodynamic instability	40 (39.6)
Respiratory distress	18 (17.8)
Neurological impairment	27 (26.7)
AKI	9 (8.9)
Monitoring	7 (6.9)

AKI: Acute kidney injury.

Mechanical ventilation was necessitated in 67.3% of parturient. The interventions needed were insertion of a central venous line, an arterial line, renal replacement therapy, and blood transfusion (Table 4). The median length of ICU stay was 3 (1-50) days. The reported mortality rate was 27.7% (28/101) among these patients admitted to the ICU. The highest mortality was observed in patients with postpartum hemorrhage (25%) and non-obstetric causes (50%). Overall, adverse fetal outcomes (intrauterine death or stillbirth) were more frequent in non-survivors (Table 5).

Table 4 Critical care interventions required in obstetric patients admitted to the intensive care unit.

Intervention	n (%)
Need for mechanical ventilation	68 (67.3)
RRT	27 (26.7)
CVC	66 (65.3)
Arterial line	70 (69.3)
Vasopressor required	54 (53.5)
Blood transfusion	54 (53.5)

RRT: Renal replacement therapy; CVC: Central venous line.

Table 5 Relationship between diagnosis and mortality in obstetric patients admitted to the intensive care unit, n (%).

Diagnosis	Mortality
PPH	7 (25)
Hypertensive disorders of pregnancy	3 (10.7)
CAP	3 (10.7)
Puerperal sepsis	1 (3.6)
Non-obstetric causes	14 (50)

PPH: Postpartum haemorrhage; CAP: Community-acquired pneumonia.

APACHE II, SAPS 2, MEOWS SOFA scores of 21 (14-26.5), 36 (28.7-43), 6 (4-7) and 5 (4-6) significantly predicted mortality (P < 0.05) in non survivors (Table 6). The area under the receiver operating characteristic curve for APACHE II 0.736 (95%CI: 0.623-0.849), SAPS II 0.785 (95%CI: 0.678-0.893) MEOWS 0.722 (95%CI: 0.607-0.836) and SOFA 0.653(95%CI: 0.53-0.773) shows a good discrimination capacity for prediction of mortality (Figure 1).

Figure 1 Receiver operating characteristic curves for Acute Physiology and Chronic Health Evaluation II, Simplified Acute Physiology Score II, Modified Early Obstetric Warning Score, and Sequential Organ Failure Assessment. ROC: Receiver operating characteristic; MEOWS: Modified Early Obstetric Warning Score; APACHE II: Acute Physiology and Chronic Health Evaluation II; SOFA: Sequential Organ Failure Assessment; SAPS II: Simplified Acute Physiology Score II.

Table 6 Comparison of mortality prediction scores between survivors and non-survivors, median (interquartile rage).

Score	Survivors	Non-survivors	P value
MEOWS	4 (3-5)	6 (4-7)	< 0.0001
APACHE II	12 (8-16)	21 (14-26.5)	< 0.001
SOFA	4 (3-5)	5 (4-6)	0.016
SAPS II	23 (18-30)	36 (28.7-43)	< 0.001

MEOWS: Modified Early Obstetric Warning Score; APACHE II: Acute Physiology and Chronic Health Evaluation II; SOFA: Sequential Organ Failure Assessment; SAPS II: Simplified Acute Physiology Score II.

On univariable logistic regression, higher MEOWS [odds ratio (OR) = 2.14, 95%CI: 1.50-3.05; P < 0.001], SAPS II (OR = 1.11, 95%CI: 1.05-1.17; P < 0.001), APACHE II (OR = 1.15, 95%CI: 1.07-1.24; P < 0.001) and SOFA (OR = 1.56, 95%CI: 1.20-2.02; P = 0.001) were each associated with increased odds of maternal death. Need for vasopressor support (OR = 7.59, 95%CI: 2.06-27.91; P = 0.002) and invasive arterial monitoring (OR = 4.84, 95%CI: 1.05-22.40; P = 0.044) were also associated with mortality. In the multivariable model including SAPS II, non-obstetric etiology, vasopressor use, postpartum status, and age, SAPS II remained independently associated with mortality (adjusted OR = 1.10 per point, 95%CI: 1.03-1.18; P = 0.005).

DISCUSSION

In the present study, the mean age of parturient admitted to the ICU was 27.84 ± 5.2 years, which was higher than that observed in the previous studies[3,4]. Data from the Centers for Disease Control and Prevention in 2020 indicated a persistent increase in the average age of parturient in the United States. Approximately 19% of all pregnancies and 11% of all first pregnancies in the United States occurred in women aged 35.5 years[5]. This trend is not exclusive to the United States; internationally, there is a tendency to postpone childbearing, with the majority of nations seeing a rise in the age of first pregnancy[6].

In the present study, hypertensive disorders of pregnancy (20.7%) and postpartum hemorrhage (19.8%) were the predominant reasons for ICU admission. The prevalence of postpartum hemorrhage and hypertensive disorders of pregnancy aligns with findings from other studies[2-4]. A rise in the incidence of postpartum hemorrhage has been seen in comparison to prior investigations[7]. According to a review by Owen et al[8], the heightened occurrence of hemorrhage may be attributed to the rising frequency of cesarean deliveries. The worldwide incidence and prevalence of cesarean sections rose from 16 million (12.1%) in 2000 to 30 million (21.1%) in 2015[9]. Cesarean delivery increases the incidence of perioperative obstetric hemorrhage and morbidly adherent placenta in subsequent pregnancies. In the majority of cases in our study, delivery was by caesarean section (58.4%).

Non-obstetric conditions such as pneumonia, sepsis, acute kidney injury, and stroke represented 40% of admissions. However, they caused 50% of deaths, demonstrating that obstetric critical care must encompass both pregnancy-specific and general medical management.

The severity of illness in this obstetric ICU cohort demanded extensive interventions across multiple organ systems. With more than two-thirds requiring mechanical ventilation, over half needing vasopressor support and blood transfusion, and 26.7% requiring renal replacement therapy, these findings demonstrate the high prevalence of multi-organ dysfunction and underscore the critical importance of specialized multidisciplinary care in obstetric ICUs.

The overall mortality rate was 27.7%, higher than some regional studies, possibly due to referral bias and the severity of illness in our cohort. As this study was conducted at a tertiary referral center, many patients were booked and referred from peripheral facilities, often arriving with advanced complications, which may have contributed to poorer outcomes. Mortality was disproportionately higher among patients with postpartum hemorrhage and non-obstetric causes such as sepsis and stroke. Hemodynamic instability and respiratory failure were the leading immediate causes of ICU transfer and death.

Fetal outcomes closely paralleled maternal condition: 81.1% of pregnancies resulted in live births, while intrauterine death and stillbirth were seen in 12.8% and 2.9% of cases, respectively. Adverse fetal outcomes were more common among women requiring advanced organ support and in non-survivors. Cesarean section was the predominant mode of delivery (58.4%), reflecting the emergent nature of obstetric complications.

Various tools for mortality prediction have been developed for critically ill patients, including APACHE II, SAPS 2, SOFA, and MEOWS in obstetric populations. Our investigation found that non-survivors had much higher scores than survivors (P < 0.05) and that the receiver operating characteristic curves showed good predictive power for mortality. However, as reported in other studies, these scores overestimated obstetric patients’ mortality[10,11]. Physiologic changes in pregnancy affect the vital signs and laboratory values in parturient and affect the estimations of each score, causing an overestimation of mortality in this subset of patients. The MEOWS and similar early warning systems are widely used for bedside triage and early detection of clinical deterioration, with a focus mainly on morbidity. The World Health Organization Maternal Severity Score and Maternal Severity Index have also shown better calibration and discrimination in predicting mortality than general ICU scores. The modified SOFA also improves accuracy when pregnancy-adjusted cutoffs are applied. In addition, the World Health Organization near-miss criteria are valuable for identifying severe maternal morbidity and organ dysfunction. However, they serve more as surveillance and audit tools than as predictive scores[12]. An integrated approach combining obstetric-specific tools, such as the Maternal Severity Index, with general ICU severity scores may provide the most accurate risk stratification for critically ill obstetric patients.

Our findings suggest that SAPS II is the most reliable among conventional ICU scores for obstetric patients. However, it must be interpreted alongside other obstetric-specific tools, clinical judgment, and clinical indicators. Scoring systems offer functional risk stratification, yet they should complement rather than replace holistic obstetric critical care assessment. An integrated approach combining validated scores, pregnancy-adjusted physiology, and timely interventions remains essential to reducing maternal mortality.

Critically sick obstetric patients provide a challenge for both intensivists and obstetricians. In a study by Kaur et al[13], 87% of obstetricians favored separate critical care units. A closed ICU will help manage these patients better than closed ICUs of various specialties. Obstetric critical care is a blossoming subspecialty that necessitates a comprehensive understanding of critical care medicine and obstetric science. In their review, Edwards et al[14] concluded that obstetric critical care is not well covered in most curricular programs, and training is also inadequate due to fewer obstetric admissions in the general ICU. These further probes the need for separate obstetric intensive care and training in managing parturient in the ICU.

The Limitations of the study are that the retrospective design limits our ability to capture all relevant clinical details and may introduce selection bias. The single-center design may limit generalizability to other settings with different patient populations, resources, or care models. The relatively small sample size, while representative of the low frequency of obstetric ICU admissions, limits the power for subgroup analyses and multivariable modelling. Also, as this study was conducted at a tertiary referral center, many patients were referred from peripheral facilities with advanced disease, which may have introduced referral bias and contributed to the relatively high observed mortality.

CONCLUSION

To conclude, with advances in reproductive medicine and increasing age at conception, more parturient may present to the critical care unit with hypertensive disorders, hemorrhage, morbidly adherent placenta, and other non-obstetric causes demanding obstetric and critical care. The high rate of invasive interventions and the substantial maternal and fetal mortality highlight the need for early recognition, timely referral, and multidisciplinary care. Establishing dedicated obstetric critical care units, supported by standardized management protocols and specialized training, represents a crucial step toward reducing maternal mortality and improving outcomes for both mothers and infants. Ultimately, reducing maternal mortality and morbidity requires sustained commitment to excellence in obstetric critical care, supported by evidence-based practice and continuous quality improvement initiatives.