Obesity in pregnancy

Definition

• According to the WHO, obesity in adults is a body mass index of at least 30 kg/m², and overweight a BMI of at least 25 kg/m².
• For risk assessment in pregnancy, the pre-pregnancy BMI is used.

Occurrence & epidemiology

Epidemiology

• Overweight and obesity affect up to two thirds of pregnancies, with a rising trend worldwide.
• Obesity in pregnancy is most frequent in areas of high deprivation and among older mothers.

Aetiopathogenesis

Aetiology and pathogenesis

• Obesity promotes pre-eclampsia through insulin resistance, which promotes endothelial dysfunction, and through a systemic pro-inflammatory state due to cytokines from adipose tissue.

Clinical features

Clinical features and complications

• Pregnant women with overweight or obesity are at higher risk of all pregnancy complications, especially gestational diabetes and pre-eclampsia.
• The risk of miscarriage and stillbirth is increased, and obesity is a key risk factor for postpartum haemorrhage.
• The most common outcome of gestational diabetes for the baby is macrosomia, which increases the risk of birth injuries such as bone fractures.
• Nevertheless, most women with a BMI above 25 kg/m² have a normal, uncomplicated pregnancy.

Keep learning in the app

Further reading (selection)

1. J Hum Nutr Diet 2022: Overweight, obesity and excessive weight gain in pregnancy as risk factors for adverse pregnancy outcomes: A narrative review (PubMed Central)
2. WHO fact sheet: Obesity and overweight

Cross-references