Weight Gain During Pregnancy
Most women gain between 12kg and 16kg in weight during pregnancy. Much of the extra weight is due to your baby growing. However, putting on too much weight can affect your health in a negative way. Being overweight can increase the risk of complications to both you and your baby. It is important that you eat a healthy diet to reduce the risks in this pregnancy and in future pregnancies. Stay active every day by taking time for exercise such as walking, swimming or pregnancy yoga.
In Ireland almost 20% of women are overweight before they get pregnant. At your first antenatal visit the midwife will record your weight and height to calculate your body mass index (BMI). A healthy BMI is above 18.5 and less than 25. A person is considered overweight if their BMI is above 25, obese if the BMI is above 30, severely obese with a BMI over 35 and morbidly obese when the BMI is over 40. The risk of complications rises with a higher BMI.
If you are underweight (BMI less than 18.5) or are carrying more than one baby, you may be at risk of premature delivery or a baby with low birth weight. It is important to gain enough weight to support your baby’s growth as well as your own health. Ask your doctor or midwife for a referral to see the dietitian if you are underweight or having twins or more.
Risks of a Raised BMI
Some complications associated with being overweight include a thrombosis or blood clot, high blood pressure or the development of gestational diabetes. If you have a BMI over 30 you are three times more likely to develop diabetes during your pregnancy compared to a woman with a normal BMI. If you are overweight, your baby will have an increased risk of obesity and diabetes in later life. For this reason all women with a BMI greater than 30 will have their blood glucose levels checked during the pregnancy.
Pre-eclampsia is a condition in pregnancy which is associated with high blood pressure. If you have a high BMI at the beginning of your pregnancy your risk for developing pre-eclampsia is doubled compared to women with a normal BMI. Pregnant women have an increased risk of developing a blood clot; the risk increases with a high BMI and the doctor may consider giving you injections of a blood thinning agent if your BMI is high.
Women who are overweight have difficulty using the vitamin D stored in their bodies. Vitamin D is essential for the body to function properly. It regulates cells all over the body – including the brain, heart, kidney, bone, bowel, skin and the immune system. Vitamin D is important for bone health because it controls calcium and phosphorus levels in the blood and may decrease the risk of heart attack and stroke. For your baby it is essential for strong bones and teeth. It also may play a role in preventing diabetes. Women who have a high BMI are recommended to take a daily supplement of 10 micrograms of vitamin D during pregnancy.
If you are overweight we can give you extra help and support during pregnancy to minimise the risk of complications for you and your baby. If you are concerned about your weight, talk to your midwife or doctor. They can arrange an appointment for you to see the dietitian or another specialist. The dietitian will focus on minimizing weight gain during your pregnancy and on healthy eating.