The previous recommendation was that mothers could allow themselves a weight gain during pregnancy of about 10 kilo during pregnancy, but nowadays mothers gain more weight without causing themselves weight problems later on.
In the first place, the body supplies the foetus with nutrition, but when the mother is very restrictive with food the birth weight will be lower. This can entail risks if the birth happens to be premature and the baby weighs far less than normal.
The necessary weight increase the foetus needs occurs mainly during the last part of the pregnancy. If you are hungrier than usual at the beginning, then make sure to eat a balanced diet, but be careful with the fat and sugar content. Omega 3 is important for a growing child, take Omega 3 supplements or eat fatty fish.
How much you allow yourself to gain in weight during your pregnancy depends on how much you weighed before. Those who weighed a lot don't need to gain so much, since the body already has nutrition which it can give to the foetus. Those who are very slim must allow themselves a larger weight increase in order to reduce the risk that the child will be underweight when born. This, among other things, has been investigated at The Karolinska Institute in Stockholm by Agneta Öhlin and Stephan Rössner. They found that a weight increase of 5 kilo or more after a pregnancy is not unusual and there is a distinct connection between the weight increase and the remaining weight after the pregnancy.
The ideal birth weight is now considered to be between 3.5 and 4.0 kilo.
In USA the National Academy of Sciences (NAS) has produced a table of recommended weight increases during pregnancy. In order to use the table you must first calculate your Body Mass Index (BMI). This is done by dividing your weight in kilo by your length in meter twice. (Your nurse will probably do all this for you). For example, if you weigh 70 kilo and your length is 1.6 meter, you divide 70 first by 1.60 which gives 43.75 and then divide 43.75 by 1.60 which gives 27.3 and this is your BMI. Use our BMI calculator.
According to the NAS, the table gives the recommended weight increases during pregancy for different BMI values before pregnancy:
|BMI-value||Recommended weight increase|
|kg (kilos)||lbs (pounds)|
|Less than 19.8||about 12.5 - 18.0 kg||about 27 - 39 lbs|
|19.8 - 26||about 11.5 - 16.0 kg||about 25 - 35 lbs|
|26 - 29||about 7.0 - 11.5 kg||about 15 - 25 lbs|
|over 26||at least 6 kg||at least 13 lbs|