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

26
1 Which mothers died, and why
Obesity in pregnancy is usually defi ned as a Body Mass Index of 30 or greater at booking. In the UK there
are no national statistics about the prevalence of obesity in pregnancy. The Health Survey for England
has shown a steady increase among the general population of childbearing age since the mid 1990s and
a study of pregnant women in Glasgow showed a signifi cant increase over a recent decade 15 . Prevalence
fi gures in cross-sectional research studies have varied from 11% to 20% 14, 16, 17 .
Obesity in pregnancy is associated with increased risks of complications for both mother and baby and a
summary of these is given in Box 1.4. Obese women are more likely than non-obese women to experience
spontaneous fi rst trimester miscarriage 18 and to develop gestational diabetes 19 , pre-eclampsia 18 and
thromboembolism during pregnancy 15 . In this triennium, 14 (nearly half) of the 31 women with a known BMI
who died of a thromboembolic event were obese.
Women with obesity in pregnancy also have higher rates of induction of labour, caesarean section and
postpartum haemorrhage 15,20 and there is an increased risk of post-caesarean wound infection 21 .
There is also evidence that babies of obese women have signifi cantly increased risks of adverse
outcomes, including fetal congenital anomaly, prematurity, stillbirth and neonatal death 22-27 .
Box 1.4
Risks related to obesity in pregnancy
For the mother
Increased risks include
• Maternal death or severe morbidity
• Cardiac disease
• Spontaneous fi rst trimester and recurrent miscarriage
• Pre-eclampsia
• Gestational diabetes
• Thromboembolism
• Post caesarean wound infection
• Infection from other causes
• Post partum haemorrhage
• Low breast feeding rates.
For the baby
Increased risks include
• Stillbirth and neonatal death
• Congenital abnormalities
• Prematurity.