Sophie G Ten Have, Moska Nazir, Menno V Huisman, Tim I M Korevaar, Marieke J H A Kruip, Saskia Middeldorp, Annemarie G M G J Mulders, Koen Verdonk, A Titia Lely, Wilma J Nusselder, Judith Kooiman
Low SES is associated with higher VTE risk during pregnancy and postpartum, highlighting persistent maternal health inequalities. Further research is needed to determine whether SES indicators improve VTE risk prediction and stratification in obstetric populations.
BACKGROUND: Venous thromboembolism (VTE) is a leading cause of maternal morbidity and mortality. While socioeconomic status (SES) is associated with adverse maternal and perinatal outcomes, its association with pregnancy-related VTE has not been studied.
OBJECTIVES: This study aims to quantify the association between SES and pregnancy-related VTE in the Netherlands.
METHODS: We conducted a retrospective nationwide cohort study, including all pregnancies resulting in births (> 16 weeks' gestation) in 2014-2015 from the Dutch Perinatal Registry (Perined). These records were anonymously linked to healthcare and sociodemographic data from Statistics Netherlands (CBS). VTE events were identified using diagnostic and ICD10 codes. SES was assessed by equivalized disposable household income (quintiles) and maternal education levels (low, middle, and high). Associations were evaluated by performing Kaplan-Meier analyses and multivariable Cox regressions, adjusting for demographic, clinical, and obstetric factors.
RESULTS: Among the 334 828 included pregnancies, an absolute VTE risk of 0.31% (95% CI 0.29-0.33) was observed. Compared to women in the highest income quintile (Q5) (0.22%, 95% CI 0.18-0.26), those in the three lowest quintiles had higher VTE risks (Q1: 0.37%, 95% CI 0.32-0.42, aHR 1.70, 95% CI 1.33-2.18; Q2: 0.36%, 95% CI 0.31-0.41, aHR 1.69, 95% CI 1.33-2.15; Q3: 0.33%, 95% CI 0.29-0.37, aHR 1.51; 95% CI 1.20-1.90). Low and middle education levels were also associated with higher VTE risks (Low: 0.42%, 95% CI 0.35-0.48, aHR 1.83, 95% CI, 1.48-2.26; Middle: 0.36%, 95% CI 0.33-0.40, aHR 1.61, 95% CI 1.37-1.89). Modelling both SES indicators concurrently and sensitivity analyses yielded similar results.
CONCLUSION: Low SES is associated with higher VTE risk during pregnancy and postpartum, highlighting persistent maternal health inequalities. Further research is needed to determine whether SES indicators improve VTE risk prediction and stratification in obstetric populations.