Venous Thromboembolism Risk Assessment and Prophylaxis in Obstetrics Patients in a Tertiary Health Center in Jeddah, Saudi Arabia

Aim The study aimed to estimate the proportion of patients who were evaluated for thrombosis risk and received appropriate thromboprophylaxis, if indicated, in King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia. Method This was a retrospective cross-sectional study conducted among inpatients from May 1 to August 31, 2020, in KAUH. Results Out of 298 pregnant women, the mean age was 32.09 ± 5.29 years. A total of 136 (45.6%) were obese and 97 (32.6%) were overweight. There was a significant relationship between Caprini score categories and the following variables: age, body mass index (BMI), medical disease, history of deep vein thrombosis (DVT), mode of delivery, prophylaxis, and its duration (p < 0.05). Conclusion Awareness about thromboprophylaxis in reducing the risk of developing venous thrombosis has increased compared to before, with more than half of the cases receiving it regardless of the risk level. The highest risk of venous thromboembolism (VTE) was found in older women, obese women, and those with a previous history of DVT. Low-molecular-weight heparin (LMWH) was the main prophylaxis in the hospital with an average duration of three days.


Introduction
Obstetric-associated venous thromboembolism (VTE) is an important, yet preventable, cause of mortality and morbidity during pregnancy and the postpartum period [1,2].
Pulmonary embolism (PE) is considered the second leading cause of maternal death in Saudi Arabia [3].In addition, the risk of deep vein thrombosis (DVT) increases five to 10 times during pregnancy, and this elevated risk may persist for up to 12 weeks postpartum [2].In developed countries, the incidence of VTE during pregnancy ranges between one and two cases per 1,000 pregnancies [4].In Saudi Arabia, the reported incidence of VTE during pregnancy and the puerperium is 1.25 cases per 1,000 deliveries [5].Moreover, the incidence of VTE is found to be higher in women during their childbearing years [6].VTE is a multifactorial disease that manifests clinically as DVT and PE [7].Risk factors for VTE in obstetric patients include multiparity, obesity, advanced maternal age, repeated cesarean sections, and consanguineous marriages, with the majority of the obstetrical population in Saudi Arabia being marked as high-risk [5].In addition, hospitalized women have various risk factors for developing VTE [8].Therefore, VTE risk assessment and thromboprophylaxis for high-risk groups can dramatically minimize PE-related mortality [9].Despite decades of attention and well-publicized guidelines, the utilization rates of VTE risk assessment and prophylaxis remain suboptimal globally [10][11][12].
In Saudi Arabia, thromboprophylaxis is underutilized in 50% of obstetric patients [5].Therefore, this study aims to estimate the proportion of patients at King Abdulaziz University Hospital (KAUH) in Jeddah, Saudi Arabia, who were assessed for thrombosis risk and received appropriate thromboprophylaxis when indicated.
This retrospective cross-sectional study was conducted among inpatients at KAUH from May 1, 2020, to August 31, 2020.KAUH, a teaching tertiary center located in Jeddah, Saudi Arabia, is renowned for its comprehensive healthcare services and important educational contributions.
Ethical approval for this study was obtained from the Institutional Review Board (IRB) of KAUH (Reference No. 250-15).The study adhered to the ethical standards outlined in the Declaration of Helsinki, ensuring the protection of patient rights and maintaining data confidentiality.
Data were retrospectively collected from the hospital's electronic medical records system.The study included obstetric inpatients with a length of stay exceeding one day, who were evaluated for thrombosis risk during the specified period from May 1, 2020, to August 31, 2020.Patients already receiving anticoagulant therapy upon admission and those admitted with a primary diagnosis of VTE were excluded.The electronic medical records offered extensive patient data, ensuring the precision and dependability of the collected information.
Thrombosis risk was evaluated using the Caprini risk assessment model, a validated tool employed in clinical practice since 2005 [13].The Caprini score is calculated based on various risk factors, such as patient age, surgical history, presence of malignancy, and other comorbidities, such as stroke, acute myocardial infarction, prior episodes of VTE, positive family history of VTE, sepsis, varicose veins, hormonal therapy, oral contraceptive, and bed rest.Patients were classified into four risk categories based on their Caprini scores: low risk (0-1), moderate risk (2), high risk (3)(4), and highest risk (≥5).This stratification enabled the classification of patients according to their likelihood of experiencing thrombotic events.Data were systematically recorded using structured Google Forms (Google LLC, Mountain View, California, United States), which encompassed various fields: patient information (file number and demographics, such as age, gender, weight, height, and BMI), clinical details (admission diagnosis, active diseases, and past medical history including previous VTE), thrombosis risk assessment (Caprini score and its components), and details regarding prophylaxis (type of prophylaxis administered, such as low-molecular-weight heparin (LMWH), unfractionated heparin (UFH), warfarin, aspirin, and mechanical devices, including the dose, route of administration, and duration).This structured approach ensured comprehensive and consistent data collection across all patients included in the study.
Data analysis was conducted using the IBM SPSS Statistics, Version 21.0 (released 2012, IBM Corp., Armonk, NY).Descriptive statistics were utilized to summarize quantitative data, presenting frequencies (numbers and percentages) for categorical variables.A crosstab analysis was performed to investigate the relationship between patients' thrombosis risk levels and the administration of VTE prophylaxis.This analysis aimed to identify patterns and evaluate the appropriateness of prophylactic measures based on risk stratification.The chi-square test was employed to assess the statistical significance of the relationship between categorical variables.A significance level of p < 0.05 was considered statistically significant, indicating a meaningful relationship between the variables under investigation.

TABLE 3: Prophylaxis
The data were expressed as frequency (%) or mean ± standard deviation (minimum-maximum).
The admission diagnoses were categorized into different categories, as presented in Table 4 and Table 5.

TABLE 5: Other maternal conditions and complications
The data were expressed as frequency (%) or mean ± standard deviation (minimum-maximum).
The results in Table 6 and Table 7 present a significant relationship between the Caprini score categories and several variables: age, BMI, medical history, history of DVT, mode of delivery, type of prophylaxis, and duration of prophylaxis.Older women, obese individuals, those with a previous history of DVT, those undergoing cesarean section, and those receiving longer durations of prophylaxis exhibited higher risk rates compared to others.

Discussion
VTE remains a primary cause of maternal mortality, despite being a preventable condition.A systematic review of maternal mortality conducted by the World Health Organization highlighted that embolism accounted for 14.9% of maternal deaths in developed countries [14].
This study identified a significant incidence of VTE in 52.7% of patients when comparing those in high-and moderate-risk categories.The rate of thromboprophylaxis administration was 60.8%, which contrasts with findings from a Ghana study where the DVT risk rate was 36.4%, and only 6.1% (5/82) of at-risk participants received VTE prophylaxis [15].Similarly, Revell et al. reported that a small proportion of at-risk obstetric patients met prophylaxis criteria (7.0% antenatal and 41.0% postnatal patients) [16].In addition, Alsayegh et al. noted that despite a 32% higher risk of VTE, only 8.3% received recommended prophylaxis [1].These disparities may stem from various socioeconomic factors, geographic differences, sample sizes, and study methodologies.The low prophylaxis rate could be attributed to insufficient awareness of the important risks and benefits associated with VTE prophylaxis in these cases.
In this study, obesity emerged as an important risk factor associated with the highest risk of DVT (p < 0.0001).This finding aligns with the Arab Gulf study, where obesity rates among pregnant women, excluding Oman, were notably high and approaching epidemic levels [17,18].Obesity commonly coexists with other conditions necessitating appropriate prophylaxis during pregnancy, thereby compounding the risk of VTE in these cases.While obesity alone has been identified as a risk factor for VTE during pregnancy [19], it does not independently indicate the necessity for VTE prophylaxis unless accompanied by other risk factors.
Unfortunately, there is a lack of conclusive studies specifically evaluating the benefits of routine prophylaxis for morbidly obese pregnant women.
In this study, a significant relationship was observed between age and the risk of DVT, with older women exhibiting a higher risk compared to younger women.This finding is consistent with another study that reported an average age of 33.2 years among DVT cases, suggesting the impact of age-related variables on thromboembolic risk [20].In addition, the Royal College has reported that pregnant women aged 35 years and older are at increased risk of thromboembolic events [20].
In this study, only eight cases had diabetes, including type 2 diabetes or gestational diabetes mellitus.This contrasts with findings from studies in Ghana and Norway, which identified a significant relationship between diabetes mellitus and the risk of DVT [15,21].Another notable risk factor identified was a previous history of DVT (p < 0.0001), consistent with findings from studies in the Arabian Gulf [17].
This study has several limitations.The retrospective design and single-center setting limit its generalizability to broader populations.The short duration of the study period may not fully capture longterm trends in thromboembolic events.In addition, the sample size might be inadequate to detect all potential risk factors comprehensively.Future research should focus on conducting larger, multicenter studies to address these limitations and provide more robust insights into thrombosis risk and prophylaxis

TABLE 1 : Demographic characteristics of the patients (n= 298)
Data were expressed as frequency (%) or mean ± standard deviation (minimum-maximum).As shown in Table2, less than a quarter (20.5%) of the patients had a chronic illness.Only three cases had a previous history of DVT.More than half (60.1%) underwent a cesarean section.Regarding primary diagnoses on admission and Caprini score categories, LMWH was administered as prophylaxis in 180 (60.4%) cases, with a common dose of 40 mg given in 168 (56.4%) instances, and an average duration of 3.39±5.89days,aspresentedin Table3.Characteristics N (%)

Table 6
and Table7present the relationship between the Caprini score and each variable.Table6presents categorical variables, while Table7presents continuous variables.

TABLE 7 : Relation between the Caprini score and each variable (continuous variables)
indicates statistical significance at the p < 0.05 level.** indicates statistical significance at the p < 0.01 level. *