Weight gain for a healthy pregnancy.
Much like all other things pregnancy related, weight gain is specific to your situation; there is no right or wrong, but it is a good idea to be mindful of healthy weight gain ranges during pregnancy. Everyone will gain weight very differently during a pregnancy and this is influenced by a number of factors, such as your size and weight prior to pregnancy, hormone and thyroid levels, general health and fitness before and during pregnancy, as well as genetic disposition. The same can be said for weight loss after pregnancy, but good health generally, rather than timelines and targets, should be the focus. Healthy weight gain is a normal and natural part of pregnancy, and shouldn’t be feared.
Mindfulness around healthy weight is important at all times to support general good health, but this is particularly the case while pregnant. Many women seem to be focused on one end or the other of the weight gain spectrum – over concerned with putting on too much weight, or not mindful at all about weight gain, therefore being at risk of gaining an excessive amount. We know that neither of these situations is ideal for a healthy pregnancy, and potentially harmful for returning to healthy weight range after pregnancy, which can increase risk in future pregnancies. Rather, the focus should be on maintaining a healthy weight range throughout pregnancy, so there is little impact on the health of you and your baby.
Women who are overweight (high body mass index) prior to becoming pregnant, or who gain excessive amounts of weight during pregnancy are more at risk of miscarriage, gestational diabetes, high blood pressure, premature birth, caesarean section, and baby’s requiring intervention or admission to nursery following birth (American College of Obstetricians and Gynecologists, 2015). Further, it has been found that in women who gain extra weight between first and subsequent pregnancies, or don’t return to a healthy weight range after pregnancy, the risk of these complications is additionally 1.5 times more heightened in subsequent pregnancies (Cnattingius & Vallamor 2015).
Similarly, women with low body mass index (BMI) prior to pregnancy or with limited weight gain during pregnancy are also at risk of miscarriage and preterm birth, as well as most commonly, low birth weight of baby. This is due to an association with low plasma volume in low BMI women and low birth weight. Low plasma volume results in lowered cardiac output which in turn results in lower utero-placental blood flow with consequent decrease in the nutrient transfer to the growing fetus (Bhattacharya et al 2007). In women with low BMI, there is evidence to show that a normal weight gain during pregnancy (in excess of 12kgs) will increase the likelihood of a good pregnancy outcome.
Body mass index (BMI) is calculated as weight (kg) divided by height (m) squared. The resulting number can then be categorized into ranges.
Underweight (BMI <18.5), normal weight (BMI 18.5-24.9), overweight (BMI 25-29.9), obese (BMI 30-35) and severely obese (BMI >35).
Your pre-pregnancy BMI is what determines what is a healthy weight gain range for you.
- For women that are in the underweight category prior to pregnancy (BMI less than 18.5) healthy weight gain during pregnancy is 12.5kg – 18kg.
- For women that are in the healthy weight category prior to pregnancy (BMI 18.5 – 24.9) healthy weight gain during pregnancy is 11.5kg – 16kg.
- For women that are in the overweight category prior to pregnancy (BMI 25 – 29.9) healthy weight gain during pregnancy is 7kg – 11.5kg.
- For women that are in the obese category prior to pregnancy (BMI greater than 30 – 35) a healthy weight gain during pregnancy is 5kg – 9kg.
Maintaining weight gain within these ranges during and returning to healthy BMI after pregnancy can reduce the risk of obesity, heart disease and type 2 diabetes for both you and your child later in life (Early life nutrition, 2015).
Pregnancy is not a time for dieting or restricting intake, nor being under the impression you’re ‘eating for two’ – it’s a time for being in the best health you can be, for the benefit of you and your baby. Light to moderate exercise is strongly recommended to assist with maintaining good health during pregnancy; walking, swimming, yoga and Pilates are all great activities to start during pregnancy, or continue with activities such as cycling, jogging or gym classes if this is something you were doing prior.
Kindred also offers a range of community based lifestyle sessions, check out our ‘whats on’ page.