Staff including midwives and obstetricians from 16 maternity units in the north east of England also told researchers from The University of Teesside that additional abdominal fat can make it hard to feel and scan a developing baby properly.
They found the women needed more tests because of an increased risk of conditions such as pregnancy-related diabetes, high blood pressure and pre-eclampsia. They are also more likely to require an emergency caesarean – and are at an increased risk of complications, such as wound infection and blood clots, after the surgery.
Obese mothers-to-be also need specialist equipment, such as modified beds and wheelchairs.
The researchers said the practice of monitoring the height and weight of pregnant women, abandoned in the late 1980s, should be re-introduced and have also called for better education about the risks.