More than a quarter of pregnant women seen by the Northern Lincolnshire and Goole NHS Foundation Trust are obese at the time of their first screening.
This puts the area’s soon-to-be mothers amongst the most obese in England, as health professionals warn they could be putting both their own and their baby’s health at risk.
According to data from NHS Digital, around 4,410 women were weighed at their first antenatal booking appointment with the trust in the 12 months to April 2018.
Of these, 28 per cent were found to have a Body Mass Index (BMI) of 30 or above, placing them in the obese range. A further 27 per cent were deemed overweight, with a BMI of 25 or over.
When the number of underweight women is taken into account, the figures mean that less than half of all expectant mothers seen by the trust were considered to be at a healthy weight at this stage of their pregnancy, which is typically between the ten and 12 week mark.
Tam Fry, spokesman for the National Obesity Forum said: ““Getting into shape before a conception and ensuring that you are eating healthily has been a long advocated message but too few heed it.
“A woman unhealthily overweight at booking in can not only be a health risk for her foetus but also for herself.
“The increasing number of babies being born already obese is also very concerning.”
The rate of obesity amongst pregnant women could have been higher still, as accurate data was not available for February of this year.
Around 27 per cent of the country’s adult female population are obese, according to the latest annual health survey of England.
According to both the NHS and the Royal College of Midwives, obese women are more at risk of a range of complications during pregnancy.
These include a higher chance of miscarriage, high birth weight, gestational diabetes, premature birth, thrombosis, pre-eclampsia and still births.
They may also suffer complications during childbirth, with the RCM warning that overweight and obese women are at a greater risk of having to have a caesarean section or experiencing haemorrhages or shoulder dystocia - where the baby gets stuck during delivery.