Venous thromboembolism in pregnancy and the puerperium: incidence and additional risk factors from a London perinatal database

Abstract

Objective To determine the incidence of venous thromboembolism in pregnancy and the puerperium and to identify risk factors for pregnancy-related venous thromboembolism.Design Cohort study and case±control study.Setting London, UK.Population 395,335 women with live births or pregnancies of 24 or more weeks of gestation between 1988 and 1997.Methods Data extraction from the St Mary's Maternity Information System database. Random sample of 5% for case±control study.Main outcome measures Incidence of venous thromboembolism; odds ratios for variables associated with venous thromboembolism. ResultsThe incidence of venous thromboembolism was 85/100,000 maternities. There were approximately twice as many postpartum as antepartum events. Blood group A, multiple pregnancy, caesarean section, cardiac disease, delivery at gestational age of ,36 weeks, a body mass index of $25, or more and maternal age of 35 or over were all found to increase incidence of venous thromboembolism. Conclusions Although venous thromboembolism is the leading cause of maternal deaths in the UK, it is still a rare event. Most of these events are deep vein thromboses occurring in the postpartum period. Antenatally multiple birth is an important risk factor. Postnatally women who have had a caesarean section, premature delivery or history of cardiac disease should be assessed carefully for venous thromboembolism.

Thrombophilia among Chinese Women with Venous Thromboembolism during Pregnancy

“…The reason for its increased trend in the Chinese population remains unclear. The incidences of VTE and fatal pulmonary embolism (PE) during pregnancy among Chinese women were recently reported to be 160 and 1.4 per 100,000 pregnancies, respectively [5,6,7], similar to those reported in the Caucasian population [8,9,10]. Advanced maternal age, maternal obesity and cesarean delivery were risk factors for VTE during pregnancy in Chinese [5], but the rate of thrombophilia in Chinese women with VTE during pregnancy has not been studied.…”

Techniques for caesarean section

“…The major complications of caesarean section are intraoperative damage to organs such as the bladder or ureters (Nielsen 1984), anaesthetic complications, haemorrhage (Petitti 1985), infection (Duff 1986;Owen 1994)) and thromboembolism (Gherman 1999;Simpson 2001). Maternal mortality is greater after caesarean than vaginal delivery (Frigoletto 1980;Lilford 1990;Schuitemaker 1997), though it is difficult to be sure to what extent this is due to the operation or to the reason for the operation.…”

Mortality from venous thromboembolism in young Swedish women and its relation to pregnancy and use of oral contraceptives – an approach to specifying rates

“…Pregnancy is considered to be an even stronger risk factor for VTE than COC exposure, with incidence rates of between 600 and 1300 cases per million pregnancies [15,16]. A maternal VTE mortality rate of between 9 and 14 cases per million live births may be derived from Swedish [17] and English data [18].…”