Overweight and obesity have become very common worldwide in the last 30 years. This is largely because the rapid urbanization, unhealthy dietary habits and lack of physical activity. Because of these and many other factors, about half of women becoming pregnant are now overweight or obese. Obesity can be prevented and tackled at different stages of pregnancy.
Being overweight or obese while planning pregnancy may make it more difficult to become pregnant. Losing even a few kilograms of weight has been shown to increase a woman’s chance of getting pregnant. Being overweight or obese from before pregnancy also increases the risk for mother as well baby of several short and long term complications.
All pregnancies have some risks of complications but most often a pregnancy proceeds normally. However being overweight/obese during pregnancy increases the risks of some of the complications such as miscarriage, high blood pressure (preeclampsia), gestational diabetes.
The baby of an overweight/ obese mother is at risk of having congenital abnormalities such as spina bifida and some heart defects. At birth, the baby is also likely to be larger and subsequently there is increased risk of birth trauma, instrumental delivery (eg forceps) or caesarean section and intensive care admission.
When growing up, babies born to overweight/ obese mothers are at increased risk themselves of being overweight/ obese and developing diabetes later in life.
What weight you should aim for?
If you are overweight/ obese, losing some weight before pregnancy is the best option. However, it is important to not start a restrictive diet while attempting to become pregnant as this can also be harmful for your baby.
However, if like many women, you are already pregnant when starting to deal with your obesity, it is important to be aware of weight gain targets for your pregnancy (Table 1). Particularly, if you are obese (BMI greater than 30) your weight gain should be 5-9 kg and sometimes less depending on the degree of obesity. This should be discussed with your doctor and dietitian.
Table 1: Weight gain recommendations during pregnancy based on pre-pregnancy BMI
|Pre-pregnancy BMI||Recommended weight gain (Kg)|
|Underweight (<18.5 kg/m2)||12.5 – 18|
|Normal weight (18.5 – 24.9 kg/m2)||11.5 – 16|
|Overweight (25.0 – 29.9 kg/m2)||7 – 11.5|
|Obese (≥ 30.0 kg/m2)||5 – 9|
Source: Institute of Medicine (2010)
What should you consider if you are obese and pregnant?
It is important to look at maintaining a healthy diet while pregnant. Being as active as possible in your regular day is a priority. This means taking as many opportunities to walk around and to spend less time sitting. It is generally safe to continue exercising at pre-pregnancy levels but this should be verified for you personally with your doctor, as you may have specific issues such as bleeding. However, it is best to avoid strenuous exercises during pregnancy.
Being overweight or obese also means there is an increased risk of having diabetes or developing gestational diabetes. You should check your blood sugar levels and HbA1C ideally before pregnancy and if you become pregnant, check blood sugar in the 1st trimester and if it is normal then check in subsequent trimesters and if you are overweight or obese it is important to consider an earlier check during pregnancy.
After your pregnancy, it may be difficult to achieve a healthy weight range. Again healthy diet, an active lifestyle and regular and specific exercise are very important. However, highly restrictive dieting is not advisable, particularly while breastfeeding.
Getting to a healthy weight range after pregnancy reduces your risks for further pregnancies as well as improves your long term health and reduces chances of diseases like diabetes and hypertension in future.
Diet and exercise in pregnancy
It is important to have a healthy diet and active lifestyle when you are pregnant or planning pregnancy because it can help keep you and your baby healthy. This is particularly so if you are overweight or obese because obesity may have health consequences for both mother and baby. Therefore, whether you are a healthy weight or are overweight, healthy eating and regular exercise are a priority.
Eating well involves the following:
- Make sure your diet is high in a wide variety of fruit and vegetables.
- Eat lean meats, and alternatives such as legumes (kidney beans, chickpeas and lentils), eggs, nuts and seeds.
- Eat complex carbohydrates such as whole grains and cereals that are low glycaemic index.
- Include (low fat) dairy products such as milk, yoghurt and cheese or alternative sources of calcium in your diet everyday.
- Limit your quantities of high fat or sugary foods such as fast food, cakes, biscuits and bakery products.
- Fats to be taken in moderate quantities.
- Drink plenty of water.
- Consider portion size as well as food type. A typical plate of food should be approximately half vegetables or salads, one quarter proteins and one quarter grains, millets or roots and tubers. It may be worthwhile consulting with a dietitian for further support and advice.