This study defined excess weight as more than 6.8kg (15 pounds), which until recently was the minimum amount of weight gain recommended for obese pregnant women by the US Institute of Medicine. The NHS points to 7–12 kg (about 1.5-2 stones) as being a healthy amount of weight to gain in pregnancy with women carrying multiples expected to gain more. Any more than this and you may compromise your and your baby’s health – extra weight gained in pregnancy puts you at a higher risk of pregnancy and birth complications like diabetes,  pre-eclampsia, a bigger baby, and a caesarean delivery.

The study found that, on average, women retained 40 percent of the weight they gained during pregnancy one year after delivery. Compared to women who gained less than the recommended 6.8kg, women who gained 6.8-11kg (15-25 pounds) were twice as likely to retain 4.5kg (10 excess pounds); women who gained more than 35 pounds were nearly eight times more likely to retain at least 15kg (10 pounds). The study also found that younger women and first-time mums were most likely to gain too much weight.

The study underpins that obese women (those with a body mass index, or BMI, of 30 or more) should take steps to control weight gain during their pregnancies, since once your baby is born, it’s much harder to change eating habits and start an exercise program.

Try these tips for controlling pregnancy weight gain:

* Eat regular meals and small healthy snacks between meals – research shows that this eating pattern may be better for pregnant women than the traditional three large meals way of eating.
* Avoid junk food and keep snacks healthy. Fresh fruit is one of the best snacks as it’s packed with vitamins and fiber (great for helping to relieve constipation).
* Reduce your fat intake to less than 30 percent of your daily calories.
* Reduce your consumption of sweets and sweetened drinks.
* Keep a food diary to check for nutritional adequacy and portion management.
* Eat only 100-300 extra calories per day beyond what your calorie needs were before you became pregnant.
* Exercise for at least 30 minutes on most days (ask your midwife if you’re at all unsure about what you should be doing in regard to exercise).