Maternal mortality cases from pulmonary embolism: A nation-wide study in Turkey

Predictive value of D-dimer and analysis of risk factors in pregnant women with suspected pulmonary embolism after cesarean section

Background

Acute pulmonary embolism (PE) is one of the leading causes of maternal mortality, and cesarean section is an established independent risk factor for PE. The diagnostic utility of D-dimer for PE in non-pregnant women has been well-established, but its role in women with suspected PE after cesarean section is unclear. Furthermore, the optimal threshold level in this patient population is unknown. Traditional D-dimer levels have low diagnostic specificity, resulting in many pregnant women being exposed to potentially harmful radiation despite negative diagnostic imaging results. This research aimed to optimize the clinical threshold for D-dimer to improve specificity while ensuring high sensitivity and to identify risk factors for PE after cesarean section.

Methods

This retrospective study of 289 women who underwent diagnostic imaging (ventilation/perfusion [V/Q] or computed tomographic pulmonary angiography [CTPA]) for suspected acute PE after cesarean delivery from 2010 to 2021 was conducted. Clinical data and laboratory indicators within 24 h postpartum including D-dimer levels were collected for analyses.

Results

The final analysis included 125 patients, among whom 33 were diagnosed with acute PE (incidence of 11.42%, 95% confidence interval 7.7–15.1). The receiver operating characteristic curve analysis suggested that a D-dimer cut-off value of 800 ng/mL had specificity of 25.26% and sensitivity of 100% for detecting PE. The cut-off value was adjusted to 1000 ng/mL with a specificity of 34.74% and a sensitivity of 96.67%. Using a D-dimer cut-off value of 800 ng/mL (instead of the conventional value of 500 ng/mL) increased the number of patients excluded from suspected PE from 9.6 to 18.4% without additional false-negative results. Of note, a history of known thrombophilia was significantly more common in patients with PE than in those without (P < 0.05). No other independent risk factors were noted in our study.

Conclusions

The D-dimer cut-off value of 800 ng/mL ensures high sensitivity and increases specificity compared to the conventional threshold of 500 ng/mL. Utilizing this higher threshold can reduce the number of unnecessary CT and subsequently unnecessary radiation exposure, in women after cesarean delivery. Prospective studies should also be conducted to verify these results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01757-3.

Fatality rates and use of systemic thrombolysis in pregnant women with pulmonary embolism

AIMS

Data on the early course and use of systemic thrombolysis in pregnant women with pulmonary embolism associated or not with haemodynamic failure are scarce. We investigated these aspects using the information from the German Nationwide Inpatient Registry (years 2005-2016).

METHODS AND RESULTS

In Germany, all diagnoses referring to hospitalized patients are coded according to the International Classification of Diseases and Related Health Problems, 10th Revision with German Modification. We analysed data of pregnant women aged 18-50 years for whom the following diagnoses were recorded during hospitalization: (i) pulmonary embolism (I26) during pregnancy or peripartum (O09) or (ii) obstetric thromboembolism (O88.2). Haemodynamic failure at any time during the in-hospital stay was defined as need for cardiopulmonary resuscitation (OPS code 8-77) or the presence of shock (International Classification of Diseases and Related Health Problems, 10th Revision with German Modification code R57). The primary study outcome was in-hospital death. A total of 8 271 327 births were registered in Germany from 2005 to 2016. During this 12 year time period, there were 1846 hospitalizations for pregnancy-associated pulmonary embolism in patients aged 18-50, corresponding to 2.2 [95% confidence interval (CI): 2.1-2.3] cases every 10 000 births and 0.2% of all hospitalizations for pulmonary embolism in Germany. The median age was 31 years, and the median length of hospitalization was 8 days. A total of 63 deaths were reported, corresponding to an overall in-hospital fatality rate of 3.4% (95% CI: 2.7-4.4) and a pulmonary embolism-related mortality rate of 0.8 (95% CI: 0.6-1.0) per 100 000 (live) births per year. Pulmonary embolism-related deaths in hospitalized pregnant women represented 14% of all maternal deaths recorded in Germany between 2005 and 2016. A total of 135 (7.3%) women had haemodynamic failure, of whom 51 (37.8%) received systemic thrombolysis and 50 (37.0%) died.

CONCLUSIONS

Pulmonary embolism-related fatality remains substantial in pregnant women with pulmonary embolism and represents a frequent cause of maternal mortality. The use of systemic thrombolysis was reported in one third of pregnant women with pulmonary embolism and haemodynamic failure. Better preventive and management strategies should be urgently implemented in this vulnerable patient group.