Losing weight could be one of the most important ways to prepare for parenthood, according to health experts.
They say obesity reduces fertility in men and women, increases risks during pregnancy and could even make the baby more likely to grow up to become a fat adult.
The growing number of grossly overweight pregnant women is also adding to pressure on the NHS because they often need more care because of the increased risks of high blood pressure and diabetes.
Hany Lashen, a senior lecturer in obstetrics and gynaecology at the University of Sheffield, said obese mothers are more likely to suffer miscarriages in the first 12 weeks of their pregnancy and three times more likely to suffer multiple miscarriages.
If they carry full term, there is more chance of their baby being induced or delivered by Caesarean section.
He added: ‘Obesity creates a higher risk of miscarriage but nobody knows the exact cause.’
He said high blood pressure and diabetes are the biggest risks to obese expectant mothers but the risks can be increased if they need a Caesarean because the baby is overdue.
‘The baby’s getting a lot of food and, if they are getting food, they don’t come out,’ Mr Lashen added.
Some experts, like Prof Richard Fleming, of the Glasgow Centre for Reproductive Medicine, believe babies born to obese mothers are more likely to grow up to be obese themselves. He said more research is needed to find out if this is true.
Strain on NHS
The added risks to obese expectant mums are also increasing the strain on hospitals which need to offer additional care.
A report released today by the Centre for Food, Physical Activity and Obesity Research at the University of Teesside, Middlesbrough, studied 16 maternity units in the North East.
Health professionals told researchers that obese patients sometimes needed additional scans because it was hard to see the foetus and also required glucose tolerance tests because of the higher risk of gestational diabetes.
The report said hospital equipment is not always suitable for obese expectant mothers. Scales often had too low a maximum weight limit, trolleys were too small and heavier patients needed to have elective Caesareans on the gynaecology theatre tables, disrupting theatre lists and waiting times.
Obese couples are almost three times more likely to have trouble conceiving than couples of normal weight, according to another report out today.
A team in Denmark carried out the first study of obese couples, talking to 47,835 couples between 1996-2002.
The study, published online in the journal Human Reproduction, said obese couples are almost three times as likely as couples of a healthy weight to wait more than a year to conceive. Couples who are overweight are nearly 50 per cent more likely to wait longer than a year.
Prof Fleming said prospective parents should simply concentrate on eating a healthy, balanced diet if they wanted to increase their chances of having a healthy baby.
‘Reduce your calorie intake overall and increase your exercise,’ he said.
© The Press Association, All rights reserved.