Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, what information his Department holds on the average body mass index of pregnant women in the (a) most recent period for which data is available and (b) five years before the most recent period for which data is available.

The Government is committed to ensuring that all women and babies receive safe, personalised, equitable and compassionate maternity and neonatal care. As part of this, we know that it is vital to support women before, during and after pregnancy.

In the most recent period for which data is available, of women who reached 15 weeks gestation in October 2024 and had a body mass index (BMI) recorded by 14+1 weeks gestation, 7% were underweight (<20 kg/m²), 35% were normal weight (20-24.9 kg/m²), 30% were overweight (25-29.9 kg/m²) and 27% were obese (30+ kg/m²).

BMI data for pregnant women is not available for five years before October 2024, namely October 2019, but data was published using the previous methodology for 2018/19. Of women who had a booking appointment in 2018/19 where BMI was recorded, 3% were underweight (<18.5 kg/m²), 46% were normal weight (18.5-24.9 kg/m²), 28% were overweight (25-29.9 kg/m²) and 22% were obese (30+ kg/m²).

There have been changes in methodology and definitions used in data collection between 2018/2019 and October 2024, which means that the data, especially for underweight women, may not be directly comparable.