Pregnancy Thromboprophylaxis

Thromboprophylaxis in pregnancy and the puerperium

PREGNANCY

THROMBOPROPHYLAXIS

Prevalence

BJOG. 2001 Jan;108(1):56-60.

Venous thromboembolism in pregnancy and the puerperium: incidence and additional risk factors from a London perinatal database.
Simpson EL, Lawrenson RA, Nightingale AL, Farmer RD.

Postgraduate Medical School, Guildford, Surrey, UK.

Objectives:

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.

Results:

The 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 > or = 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.