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

Pulmonary embolism
Of the 33 women who died from pulmonary embolism, ten died during the fi rst trimester of their pregnancy
and one during the second trimester. A further three women died antenatally; two following terminations
of pregnancy and one following an ectopic pregnancy. An additional four women who collapsed in late
pregnancy from a pulmonary embolism were delivered by a peri or post mortem caesarean section; these
are also classifi ed as antepartum deaths. No women died during labour. In all, fi fteen women died in the
postpartum period, eight following a vaginal delivery and seven after a caesarean section.
The women who died
Risk factors for thromboembolism were identifi able in 26 of the 33 women. Sixteen were overweight and
four women had a past or family history of venous thromboembolism (VTE). Two died after air travel in
pregnancy, one had hyperemesis gravidarum and one had ovarian hyperstimulation syndrome (OHSS).
Three women had a history of surgery unrelated to pregnancy and one underwent craniotomy in the
puerperium. Seven had no recorded risk factors but in four of these cases details were inadequate.
Of the 21 women whose pregnancies exceeded 12 weeks’ gestation, four did not attend for regular antenatal
care. In one case, an asylum seeker saw her General Practitioner early in pregnancy but did not receive
a booking appointment until after fi ve months had elapsed. The other three women had complex lives and
were known to either be substance misusers, have child protection issues, or both. Six of the 21 women were
Black African or Caribbean and two were South Asian. Three women could not speak English.
Risk factors
Weight
The National Institute for Clinical Excellence (NICE) guideline on antenatal care recommends that every
woman should have her BMI checked at the fi rst antenatal visit and that women with a BMI over 35 are not
suitable for routine midwifery led care2 . The mother’s weight was recorded in only 25 cases and the BMI
could be calculated for only 21. Of these, sixteen were overweight, with a BMI of over 25. Twelve of these
were classifi ed as obese with a BMI over 30, including eight who were morbidly obese with a BMI over 35.
The latter included two who died after caesarean section. The highest reported BMI was 62, and another
fi ve women had BMIs over 40. Two of the morbidly obese women inappropriately had midwife-only care.
Two of the three women who suffered a Late Direct death from pulmonary embolism were also obese or
morbidly obese.
Women with a BMI of 40 or above are at a high risk of VTE but current RCOG guidelines 3, 4, 5 recommend
the same prophylactic doses of low molecular weight heparin (LMWH) for all women with a BMI over
30 or a weight exceeding 90Kg. The RCOG guideline on thromboprophylaxis during pregnancy, labour
and after normal vaginal delivery 2 recommends that “one or two risk factors alone may be suffi cient to
justify antenatal thromboprophylaxis with LMWH, for example an extremely obese woman admitted to
the antenatal ward.” This advice relies on clinical judgement and was reinforced in the last Report, but
of the eight morbidly obese women whose deaths are discussed in the present Report, six received no
thromboprophylaxis, one received an inadequate dosage and one received the correct dose but not until
some time after her caesarean section. A specifi c guideline is now required on thromboprophylaxis for
morbidly obese women.
57