Saving Mothers' Lives: - Public Health Agency for Northern Ireland

58
2 Thrombosis and thromboembolism
Age
The ages of the women ranged between 18 and 39 years with a median of 30 years. Their age distribution
is shown in Table 2.3 together with mortality rates per 100,000 maternities. This suggests a shift to a
younger age of death, despite an overall increase in age at childbearing. Although no difference was
detected in the mortality rates overall, the rate increased signifi cantly among women aged under 25 and
decreased among those aged 40 and over.
Table 2.3
Numbers of deaths attributed to pulmonary embolism and rates per 100,000 maternities by age;
United Kingdom: 1985-90 and 1997-2005*.
Numbers
Under 25 25-29 30-34 35-39 40 and over Total
1985-90 3 19 12 13 7 54
1997-99 5 6 11 8 1 31
2000-02 3 8 7 6 1 25
2003-05 9 8 10 5 1 33
1997-2005 17 22 28 19 3 89
Overall mortality rates
1985-90 0.18 1.17 1.28 4.07 12.02 1.17
1997-2005 1.05 1.28 1.51 2.15 1.80 1.43
Difference 0.88 0.11 0.23 -1.92 -10.22 0.26
95 per cent CI 0.35,1.52 -0.68, 0.89 -0.83,1.10 -4.92,0.15 1.80,12.02 -0.19, 0.69
* Detailed analyses by age were not published for 1991-93 or 1994-96.
Air travel
Of the two women died after air travel, only one followed a long-haul fl ight. One occurred in the fi rst
trimester and one in the second, suggesting that the risk is related to prothrombotic changes and not
venous stasis in late pregnancy. Unfortunately the RCOG has now withdrawn its advice for preventing
deep vein thrombosis for pregnant women travelling by air from its website. The RCOG guideline on
thromboprophylaxis2 , however, includes “long-haul travel” in its list of risk factors as shown in the Annex
to this Chapter. The recommendation of the NICE guideline on antenatal care1 is as follows: “Pregnant
women should be informed that long-haul air travel is associated with an increased risk of venous
thrombosis, although whether or not there is additional risk during pregnancy is unclear. In the general
population, wearing correctly fi tted compression stockings is effective at reducing the risk.”