Weight management during pregnancy

30.1

Introduction

• The antenatal period can be a difficult time for pregnant obese patients to manage their weight.

• There is often the misconception that a pregnant person needs to “eat for two” and a patient may need educating that a healthy, balanced diet should be maintained.

• The weight gained while pregnant can be attributed to the foetus, placenta, amniotic fluid, and maternal adipose deposits, along with plasma expansion.

• Healthcare professional should raise the issue of raised body mass index (BMI) with the patients as an important health issue.

• However, many healthcare professionals may lack the training to discuss issues regarding obesity in pregnancy and fear that such discussion could adversely affect their relationship with their patients.

• All patients should have their BMI assessed at the first antenatal booking appointment as this will guide clinicians about their weight management for the remainder of their pregnancy.

• It is important to note that prepregnancy weight has more influence on the health of the mother and baby, rather than actual weight gain during pregnancy itself.

• This is why preconception and postnatal advice regarding maintaining a healthy lifestyle is of vital importance.

30.2

Weight gain guidelines

• The American College of Obstetricians and Gynaecologists (ACOG) and the Society of Obstetricians and Gynaecologists of Canada (SOGC) advise that patients should be informed that the recommended weight gain during pregnancy for obese pregnant people should be between 5 and 9.1 kg for singletons and 11.3–19.1 kg for twin pregnancies.

• These recommendations were produced by the Institute of Medicine (IOM) in the United States, and are derived from observational studies that these weight gains reduce the risk of foetal and maternal adverse outcomes.

• It is important to note that these recommendations are based on patients living in the United States, and may not be applicable throughout the world.

• In addition, these weight gain targets are not suitable for adolescent pregnancies, as the weight gain requirements for these patients are likely to be higher than the recommendations made by the IOM.

• A more recent guideline from the Royal College of Obstetricians and Gynaecologists (RCOG) advises that there is disagreement on what constitutes a safe and healthy weight gain in pregnancy.

• Therefore, the RCOG advise that rather than a weight gain goal, women should concentrate on a achieving a healthy diet until more evidence is exists.

30.3

Risks of inappropriate weight gain

• Maternal risks of excessive weight gain include an increased chance of caesarean section, higher postpartum weight retention, preterm birth, preeclampsia, and gestational diabetes.

• Obesity has the additional long-term associations of cardiovascular disease, metabolic syndrome, type II diabetes and early mortality.

• Therefore, gestational weight gain has the potential to have wide-ranging public health implications and should be a priority for policy makers.

• In addition, an Australian study has demonstrated that patients with weight gains above the IOM recommendations have a hospital stay that is 20% longer than those patients with an appropriate weight gain. This has important financial associations for healthcare and the wider society.

The risks for the child when there is excessive gestational weight gain include:

• being born large for gestational age;

• childhood obesity;

• asthma; and

• diabetes mellitus Type 1.