TENSION Y CORRIENTE DE DISEÑO-RECTIFICADOR Voltaje alimentación en DC:

2.1. Context

Obesity is a condition in which excess body fat has accumulated to such an extent that health may be adversely affected.64 _{The worldwide prevalence of obesity has increased markedly over the past few decades,}

and the World Health Organisation (WHO) has described this trend as a ‘global epidemic’ posing a serious threat to public health.64 _{The prevalence of obesity in the general population in England has increased}

markedly since the early 1990s and currently affects an estimated 25% of adults and 18.5% of women of childbearing age.65

Body mass index (BMI) offers a useful measure of obesity and is a simple index of weight-for-height used to classify underweight, overweight and obesity in adults. BMI is calculated by dividing a person’s weight in kilograms by the square of their height in metres (kg/m2_{). Table 2.1 shows a widely accepted classification}

published by both the WHO64 _{and the National Institute for Health and Clinical Excellence (NICE).}66 _The

classification has been based largely on the association between BMI and mortality, and it therefore allows the identification of individuals or groups at increased risk.

Table 2.1. Classification of weight status according to BMI 64 66

BMI (kg/m2_{) Classification} <18.5 Underweight 18.5-24.9 Normal1_/Healthy 6 25.0-29.9 Overweight 30.0-34.9 Obese I 35.0-39.9 Obese II ≥40 Obese III

Obesity in pregnancy is widely defined as a maternal BMI of 30 or more, usually at the time of the first antenatal consultation. Until now, no national-level data on the prevalence of obesity in pregnancy have been available in the UK. Recently, however, nationally-representative data collected from 37 maternity units in England indicate that the prevalence of maternal obesity (BMI ≥30) increased from 7% in 1990 to 16% in 2007.67

Obesity carries considerable human cost. In the general population it is associated both with an increased risk of mortality from all causes and with specific increased risks of coronary heart disease, stroke, type 2 diabetes, some types of cancer, respiratory problems and musculoskeletal disorders.68 _{In women of}

childbearing age, obesity is also associated with subfertility and fertility treatment is less successful among women with obesity compared to women with a healthy BMI.69 70 _{Difficulties in conceiving may contribute to}

older age at first pregnancy, which may further increase the risk of complications and adverse outcomes.

Obesity in pregnancy carries significant additional risks for both mother and baby.71 _{Compared to women}

with a healthy BMI, women with obesity are at an increased risk of miscarriage,23 _{gestational diabetes,}26

pre-eclampsia,27 _{venous thromboembolism,}24 25 _{induced labour,}52 _{dysfunctional labour,}28 _{caesarean section,}31

anaesthetic complications,43 72 _{postpartum haemorrhage}26 _{and wound infections,}26 _{and they are less likely}

to initiate or maintain breastfeeding.32 _{Obesity may also be a risk factor for maternal death: the Confidential}

Enquiry into Maternal and Child Health’s report on maternal deaths in the 2003–2005 triennium showed that 28% of mothers who died were obese,1 _{which is substantially higher than the recently published maternal}

obesity prevalence rate of 16%,67 _{indicating that women with obesity were over-represented among those}

Babies of mothers with obesity are at increased risk too. These risks include stillbirth,10 29 _congenital

anomalies,19 _prematurity,38 _macrosomia11 26 52 _{and neonatal death.}11 29 30 _{Intrauterine exposure to maternal}

obesity is also associated with an increased risk of the infant developing obesity and metabolic disorders in childhood.73

Since obesity is associated with increased risk of multiple adverse pregnancy-related outcomes, the condition is now considered one of the most commonly occurring risk factors in obstetric practice, and obstetricians and midwives are increasingly required to care for women with obesity.

It is clear that the prevalence of maternal obesity has increased significantly over time, and also that women with obesity pose particular management problems relating both to the increased risks of specific complications in pregnancy, as well as the medical, surgical and technical challenges in providing safe maternity care. Despite these well-documented issues, there has been limited evidence on which to develop recommendations for appropriate management strategies, and it has only been in the last year that national guidance on maternal obesity has become available.12 54 _{The introduction of this guidance means that}

appropriate standards of care for the management of women with obesity in pregnancy can be implemented, with clear policies and guidelines for care available.

2.2. Aims and objectives of the national project

The overall aim of the project was to review maternal obesity in the UK.

The specific objectives were to:

• develop standards of care for women with obesity in pregnancy;

• determine the prevalence of women with a BMI ≥35 during pregnancy in the UK;

• assess how maternity services are organised for the care of women with obesity in pregnancy;

• provide UK national rates of pregnancy-related outcomes among women with a BMI ≥35;

• assess the degree to which clinical standards of care for women with obesity in pregnancy are being met.

2.3. Improving services and care

The presence of maternal obesity is an increasing problem for maternity units. The increased risks that obesity pose for both the mother and baby have been well-documented. The CMACE project was designed to investigate the scale of the problem and to assess the maternity services and care available to women with obesity. This report describes the project and its findings.

A key output of this project is the production of a set of recommendations focussing on how to appropriately manage the problems and reduce the risks associated with maternal obesity. These recommendations have been produced for healthcare providers, commissioners and policy makers. It is hoped that they will result in improved services and care, and that the recommendations will ultimately improve the health of mothers and babies exposed to obesity.