Weight Gain in Pregnancy

As your baby grows, it is normal and healthy to gradually gain weight during your pregnancy, but how much weight is healthy for you and your baby?

Weight gain is natural and indeed a healthy component of pregnancy. Throughout pregnancy a women’s body undergoes enormous physiological changes to support the growth and development of your baby. Therefore, is important to monitor and manage weight gain to maintain the health of both yourself and your baby.

What is a healthy pregnancy weight gain?

During the first trimester weight gain is relatively small, being only 1-2 kg. Progressing into the second and third trimester it is averaged that a woman gain 0.4 kg per week.

Weight gain during pregnancy can be due to several factors, a large proportion is due to the growing baby.

What are the factors that influence how much weight you gain?

• Growth of baby, placenta and uterus
• Increase in bodily fluids – amniotic fluid, blood and fluid retention
• Diet – they type of food you eat and how much
• Exercise
• Pregnancy related symptoms such as, ‘morning sickness’, nausea
• Changes in appetite, food cravings or food aversions

Body Mass Index

Body Mass Index (BMI) is used to determine whether you are in a healthy weight range by dividing your weight (kg) by your height (m²). BMI is only an estimate but is a reasonable indication of how much body fat an individual is carrying. It is often used to track and measure weight status during pregnancy and to identify potential weight problems and risk to mums’ health.

The recommended that amount of weight gained during pregnancy, depends on your pre-pregnancy BMI. The table below shows a guide to recommended weight gain based on pre-pregnancy BMI. Your BMI can be calculated and assessed by your GP, however online calculators such as, ‘NSW Government Pregnancy Weight Gain Calculator’ can also be used.

Sourced from: Queensland Government – Target weight gains during pregnancy

There are certain circumstances where weight gain will vary from the recommendations above for example, over- or under-weight women, or women with specific dietary needs. Your doctor and/or dietitian will assist in setting recommendations and goals.

What does it mean if I am above the healthy weight range?

More than 50% of pregnant women gain more than the recommended weight gain during their pregnancy. This poses health risks not only you but your baby as well.

Overconsumption of energy dense foods such as, takeaway or sweet foods and drinks may be contributing to excess weight gain. Excess weight gain can contribute to the likelihood of giving birth to a larger baby, increases likelihood of the need for a caesarean section, and the risk of developing gestational diabetes.

If you are halfway through your pregnancy and have gained more weight than recommended, it is advised and encouraged to reduce the amount of weight gained for the remainder of the pregnancy in consultation with your doctor. Strict dieting without qualified advice by healthcare profession can lead to deficiency of key nutrients negatively impacting the growth and development of your baby.

What does it mean if I am below the healthy weight range?

In order to maintain a healthy weight range during pregnancy, it is encouraged to consume a nutritious, healthy diet and introduce gentle exercises into your daily routine.

If you are eating a well-balanced diet and your appetite is normal, low weight gain is usually not overly concerning. However, if you begin to rapidly lose weight or are unable to maintain an adequate nutritious diet, it is important to consult your GP or Accredited Practicing Dietitian.

Is safe to exercise during pregnancy?

Yes, and is highly recommended, unless you have been advised not to by your doctor or healthcare professional due to pre-existing or current medical conditions or history of.

Research suggests that exercise during pregnancy improves mental and physical wellbeing, prevents excessive weight gain and reduces the risk of pregnancy-related complications. When exercising ensure you ate listening to your body, avoid heavy weightlifting and ensure your body temperature does not raise too high. If you have not exercised before, consult your GP as you may be at a higher risk of injury especially, as your body as healing post-partum.

Safe exercises to do during pregnancy:

• Walking
• Jogging
• Swimming and water aerobics
• Prenatal Pilates and yoga
• Cycling on a stationary bike or walking on a treadmill

Weight after birth

After birth it is normal to weigh more compared to pre-pregnancy, this is largely due to the body recovering after birth and extra energy reserved for breastfeeding.

It is recommended to slowly lose extra weight gained during pregnancy, around 1-2 kg (maximum) per week. Breastfeeding naturally helps to lose weight gained during pregnancy, this is due to the use of energy and fat stores for milk production.

To ensure you do not gain extra weight after pregnancy, it is recommended to consume a health nutritious diet and introduce gentle exercises. Your doctor will advise you when it is safe to do so and this is typically at your 6-week post-natal check-up. However, it is not recommended to return to intense, pre-pregnancy exercise routines until 16 weeks after birth.

Safe post-partum exercises:

• Abdominal and pelvic floor exercises
• Walking
• Swimming and water aerobics (once bleeding has stopped)
• Yoga and Pilates
• Low impact and low weight training
• Cycling

References:

The Women’s: Weight and pregnancy [internet]. Victoria: The Royal Women’s Hospital, c2021. [cited 2021 Sep 29]. Available from: https://www.thewomens.org.au/health-information/pregnancy-and-birth/a-healthy-pregnancy/weight-pregnancy

The Women’s: Understanding your weight gain is the first step towards a healthy pregnancy [internet]. Victoria, c2021. [cited 2021 Sep 29]. Available from: https://thewomens.r.worldssl.net/images/uploads/fact-sheets/Weight-gain-during-pregnancy_2021.pdf

Pregnancy, birth & baby – Health Direct: Weight gain in pregnancy [internet]. Canberra: Department of Health. c2020. [cited 2021 Sep 29]. Available from: https://www.pregnancybirthbaby.org.au/weight-gain-in-pregnancy

Nutrient Reference Values: Nutrients [internet]. Canberra: NHMRC, c2017. [cited 2021 Sep 29]. Available from: https://www.nrv.gov.au/nutrients

Eat for health: Healthy eating during your pregnancy [internet]. Canberra: NHMRC, Department of health and ageing, c2020. [cited 2021 Sep 29]. Available from: https://www.eatforhealth.gov.au/sites/default/files/files/the_guidelines/n55h_healthy_eating_during_pregnancy.pdf

Pregnancy, birth & baby: Safe return to exercise after pregnancy [internet]. Canberra: Australian Government, Health Direct, c2020. [cited 2021 Oct 5]. Available from: https://www.pregnancybirthbaby.org.au/safe-return-to-exercise-after-pregnancy

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