Pregnant women warned over obesity
Overweight women are being warned by doctors not to "eat for two" in pregnancy.
The Royal College of Obstetricians and Gynaecologists (RCOG) published new guidance urging heavier patients to stick to a healthy diet and take some exercise.
Experts have become increasingly concerned in recent years about the growing numbers of mothers-to-be who are overweight and obese at the start of pregnancy.
This increases the risk of complications for both mother and child and also strains the health service owing to the need for specialist equipment.
The guidance says that while the majority of women who are overweight (with a body mass index greater than 25) will have a straightforward pregnancy and birth, the risk of complications goes up the heavier a woman is.
Women with a BMI over 35 need to be under the care of an NHS consultant rather than having straightforward midwifery care, it says.
Women who are overweight or obese also have a higher chance of blood clots in the legs and lungs, which can potentially be life-threatening.
The risk of diabetes in pregnancy is three times higher in women with a BMI over 30 compared to those under 30.
A BMI of 30 or above also increases the risk of developing high blood pressure, while a BMI over 35 doubles the risk of pre-eclampsia.
Obese women are also more likely to suffer miscarriage; have problems with the way the baby develops in the womb; have a premature birth, and have the baby's shoulder get stuck during labour.