Venous Thromboembolism Prophylaxis Should Be Recommended for Antepartum Admissions and Cesarean Delivery if Age and Body Mass Index Are Greater Than 35.

Objective:  Venous thromboembolism (VTE) is a major cause of maternal morbidity and mortality. Current expanded treatment recommendations result in the inclusion of a large percentage of the obstetric population, which has limited their adoption. The purpose of this study was to identify a population at high risk for VTE, with minimal impact on the number of patients that would qualify for expanded treatment.

Study design:  We performed a retrospective analysis of a large obstetric population. International Classification of Diseases, 10th Revsion (ICD-10) codes for VTE were used to identify patients presenting for obstetric or postpartum (PP) care from January 2016 to March 2018. The review focused on high-risk factors (history of VTE or high-risk thrombophilia), antepartum hospital admissions that were >72 hours in the previous 30 days, use of sequential compression devices, body mass index (BMI; kg/m²), age, and mode of delivery. Pharmacologic treatment efficacy was set at 90, 75, or 50%.

Results:  During the 27-month review period, there were 120,235 deliveries and 93 had a VTE event in the index pregnancy or within 4 weeks PP (7.7/10,000 births). A history of VTE or high-risk thrombophilia was seen in 25.8% of cases. Antepartum admission was noted in 40.9%, and the combination of cesarean delivery (CD) with age and BMI ≥35 (Age + BMI + CD) was noted in 17.3% of PP cases. Targeting these latter two groups for VTE prophylaxis with a 75% efficacy suggests that 34% of the VTE events would likely have been prevented while increasing the total population treated by approximately 2%.

Conclusion:  Expanding pharmacologic prophylactical coverage to include an antepartum admission of >72 hours and those with Age + BMI + CD would result in about a one-third reduction in total VTE events with about 2% requiring treatment. These data support some of the suggested recommendations for expanded pharmacological deep venous thrombosis prophylaxis.

Key points: · CD, and BMI and age >35 are high-risk factors for VTE.. · Antepartum admission >72 hours is a high-risk factor for VTE.. · Targeting antepartum admissions, CD, and BMI and age >35 would reduce VTE events by about 33%..