Blood Res.  2019 Sep;54(3):175-180. 10.5045/br.2019.54.3.175.

Risk of venous thromboembolism in Chinese pregnant women: Hong Kong venous thromboembolism study

• Huang D
• Wong E
• Zuo ML
• Chan PH
• Yue WS
• Hu HX
• Chen L
• Yin LX
• Cui XW
• Wu MX
• Su X
• Siu CW
• Hai JJ

• KMID: 2459382
• DOI: http://doi.org/10.5045/br.2019.54.3.175

Abstract

BACKGROUND
Previous Caucasian studies have described venous thromboembolism in pregnancy; however, little is known about its incidence during pregnancy and early postpartum period in the Chinese population. We investigated the risk of venous thromboembolism in a "real-world" cohort of pregnant Chinese women with no prior history of venous thromboembolism.
METHODS
In this observational study, 15,325 pregnancies were identified in 14,162 Chinese women at Queen Mary Hospital, Hong Kong between January 2004 and September 2016. Demographic data, obstetric information, and laboratory and imaging data were retrieved and reviewed.
RESULTS
The mean age at pregnancy was 32.4±5.3 years, and the median age was 33 years (interquartile range, 29-36 yr). Pre-existing or newly diagnosed diabetes mellitus was present in 627 women (4.1%); 359 (0.7%) women had pre-existing or newly detected hypertension. There was a small number of women with pre-existing heart disease and/or rheumatic conditions. Most deliveries (86.0%) were normal vaginal; the remaining were Cesarean section 2,146 (14.0%). The incidence of venous thromboembolism was 0.4 per 1,000 pregnancies, of which 83.3% were deep vein thrombosis and 16.7% were pulmonary embolism. In contrast to previous studies, 66.7% of venous thrombosis occurred in the first trimester.
CONCLUSION
Chinese women had a substantially lower risk of venous thromboembolism during pregnancy and the postpartum period compared to that of Caucasians. The occurrence of pregnancy-related venous thromboembolism was largely confined to the early pregnancy period, probably related to the adoption of thromboprophylaxis, a lower rate of Cesarean section, and early mobilization.

Keyword

Pregnancy; Venous thromboembolism; Chinese

MeSH Terms

Asian Continental Ancestry Group*
Cesarean Section
Cohort Studies
Diabetes Mellitus
Early Ambulation
Female
Heart Diseases
Hong Kong*
Humans
Hypertension
Incidence
Observational Study
Postpartum Period
Pregnancy
Pregnancy Trimester, First
Pregnant Women*
Pulmonary Embolism
Venous Thromboembolism*
Venous Thrombosis

Figure

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  Fig. 1 Age-specific incidence of pregnancy-related venous thromboembolism.

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