Weight gain during pregnancy is normal and while many pregnant women try to minimise the extent of the weight gain, it is important to remember that this can affect both mother and baby. It is usually acceptable to gain about 10 to 12.5 kg’s during pregnancy but many factors can play a part in considering what is acceptable weight and what is excessive or too little.
From the second trimester onwards, the weight gain should be gradual but steady – around 0.2 to 0.5 kg per week. Most doctors will tell a mother not to worry about the weight issue as it shows that they are eating well and the unborn baby is getting sufficient nutrition. However, excessive weight gain can complicate the pregnancy and delivery as well as aggravate certain conditions like diabetes and high blood pressure in pregnancy.
You should always speak to your gynaecologist about your weight gain and any concerns. Dieting during pregnancy should be avoided – eating healthy and not overindulging is one thing, dieting to keep your weight down can be dangerous. Remember that cravings during pregnancy are normal and it may be your body’s way of telling you what you and the baby need.
BMI before Pregnancy
You should record your weight before falling pregnant and calculate your BMI (use our online BMI calculator) in order to assess whether your weight gain during pregnancy is too much or too little. While your weight gain in pregnancy may shift a woman with a normal BMI into the overweight range, it should not reach a point where it falls into the obese level.
If your BMI was within the normal range before you fell pregnant then gaining 10 to 12kg (maximum 16kg) is acceptable. For women who are overweight (BMI>25) before pregnancy, acceptable weight gain should be a little less – around 7 to 11kg during pregnancy.
Women who were obese before pregnancy (BMI>30) should be careful with weight gain and should not exceed 5 to 9kg during the pregnancy. Underweight women (BMI<18.5 before pregnancy) should gain between 13 to 18 kg during pregnancy.
These are general guidelines and your gynaecologist will be in the best position to advise you about the acceptable weight gain during pregnancy.
A pregnant woman who is expecting twins should not gain twice the acceptable weight during pregnancy. There may be a slight increase above the normally accepted levels but it is moderate.
Too Much Weight During Pregnancy
Gaining weight excessively during pregnancy can be dangerous. However, if your weight gain is exceeding the normally accepted levels, you should not start dieting. Instead opt for exercising – in your third trimester you may find swimming more comfortable than other types of exercise.
The risks associated with excessive weight gain during pregnancy includes :
- Gestational diabetes (pregnancy diabetes)
- Hypertension (high blood pressure)
- Early delivery
- Need for a cesarean section (C-section)
- Pre-eclampsia or eclampsia
- Varicose veins
- Excessive leg swelling and circulatory disturbances
- Heart problems in the baby
Too Little Weight During Pregnancy
Many women try to limit their weight gain during pregnancy in order to return to their original weight immediately after giving birth. These mothers also tend not to breastfeed so that they can quickly lose weight after delivery – this is irresponsible and it can put your baby at risk.
The risks associated with low weight gain during pregnancy includes :
- Low birth weight of baby
- Premature baby
- Neonatal complications