Pregnancy brings many changes, and one of the most common questions is: How much weight should I gain? Gaining the right amount of weight is essential for your baby’s growth and your health, but the amount varies depending on your body before pregnancy and changes throughout each trimester.
Let’s break down the guidelines for healthy weight gain during pregnancy, trimester by trimester, so you can feel confident and informed on your journey.
Why Is Weight Gain Important During Pregnancy?
Weight gain during pregnancy supports your baby’s development, the growth of the placenta, increased blood volume, amniotic fluid, and prepares your body for breastfeeding. However, gaining too much or too little can lead to complications such as premature birth, gestational diabetes, or difficulties during labour (RANZCOG).
Your pre-pregnancy body mass index (BMI) plays a key role in determining how much weight you should gain overall.
Weight Gain Recommendations by Pre-Pregnancy BMI
Pre-pregnancy BMI (kg/m²) |
Weight Gain Range (kg) |
Weight Gain Range (lbs) |
Underweight (<18.5) |
13 – 18 |
28 – 40 |
Healthy weight (18.5–24.9) |
11 – 16 |
25 – 35 |
Overweight (25–29.9) |
7 – 11 |
15 – 25 |
Obese (≥30) |
5 – 9 |
11 – 20 |
If you’re expecting twins or multiples, these numbers will be higher, so it’s best to discuss your individual goals with your healthcare provider (Diabetes Australia).
Weight Gain by Trimester
First Trimester (Weeks 1-12)
Most women gain between 0.5 to 2 kg (1 to 4 lbs) during the first trimester. This is often a slower period of weight gain due to morning sickness or food aversions. Importantly, you don’t need to increase your calorie intake much during this time — focus on eating a balanced, nutrient-rich diet.
Second Trimester (Weeks 13-26)
This is when weight gain tends to pick up. Aim for about 0.4 to 0.5 kg (1 lb) per week. Your baby is growing rapidly, and your body is building up fat stores and increasing blood volume. This is also when you may need to increase your daily calorie intake by around 340 calories to support your baby’s development.
Third Trimester (Weeks 27-Birth)
Weight gain continues steadily at about 0.4 to 0.5 kg (1 lb) per week. Your baby is gaining fat and growing in size, and your body is preparing for labour and breastfeeding. Calorie needs increase further, by approximately 450 calories per day (the women’s royal hospital).
Where Does the Weight Go?
Not all pregnancy weight gain is baby! Here’s a typical breakdown of where the extra kilos come from:
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Baby: 3.5 kg (8 lbs)
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Placenta: 0.7 kg (1.5 lbs)
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Amniotic fluid: 0.9 kg (2 lbs)
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Breast tissue: 0.9 kg (2 lbs)
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Increased blood volume: 1.4 – 1.8 kg (3 – 4 lbs)
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Increased fluid volume: 0.9 – 1.4 kg (2 – 3 lbs)
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Fat stores: 2.7 – 3.6 kg (6 – 8 lbs)
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Enlarged uterus: 1 – 2.5 kg (2 – 5 lbs)
Tips for Healthy Weight Gain During Pregnancy
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Eat a balanced diet rich in whole grains, lean proteins, fruits, vegetables, and healthy fats.
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Stay active with pregnancy-safe exercises like walking or swimming.
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Monitor your weight gain regularly with your healthcare provider.
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Avoid “eating for two” — focus on quality, not quantity.
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Stay hydrated and get plenty of rest.
Supporting Your Pregnancy Comfort and Wellness
Managing weight gain and comfort during pregnancy go hand in hand. Products like the Pregnancy Pillow can help you get better rest by supporting your changing body, which is essential for overall wellbeing. Additionally, using Sleepybelly’s Magnesium Body Cream can soothe tired muscles as your body adapts to these changes.
Final Thoughts
Every pregnancy is unique, so it’s important to work closely with your healthcare provider to set personalised weight gain goals. Gaining the right amount of weight at the right time supports your baby’s healthy development and helps you feel your best throughout pregnancy.
For more tips on pregnancy comfort and wellness, explore Sleepybelly’s range of maternity essentials designed to support you every step of the way.