Weight gain is an expected part of pregnancy. Your baby, placenta, blood supply, fluid and other body changes all contribute. The useful question is what pattern supports your health and your baby’s growth, rather than how to keep the number on the scales as low as possible.
Your midwife or doctor can help set an individual guide. Pregnancy is not the time to start a weight-loss diet, and a single weigh-in cannot tell the whole story.
How much weight gain is recommended?
For a pregnancy with one baby, commonly used total weight-gain ranges depend on your body mass index (BMI) before pregnancy:
- Pre-pregnancy BMI below 18.5: about 12.5–18 kg
- Pre-pregnancy BMI 18.5–24.9: about 11.5–16 kg
- Pre-pregnancy BMI 25–29.9: about 7–11.5 kg
- Pre-pregnancy BMI 30 or above: about 5–9 kg
These are guide ranges, not pass-or-fail targets. BMI is a screening measure based on height and weight; it does not describe your whole health. Your team should consider your medical history, eating pattern, symptoms and baby’s growth. Twins or other multiple pregnancies need different advice.
The ranges come from Pregnancy, Birth and Baby’s Australian guidance. Do not use your current pregnancy BMI to choose a new category each month.
Why your care team asks about weight
Weight is one piece of information used during antenatal care. Gaining substantially less or more than expected can be a reason to look more closely at nutrition, illness or other pregnancy concerns. It does not establish a diagnosis or mean you have done something wrong.
Ask what a change means in your circumstances and whether anything else needs checking. If the discussion makes you anxious, you can say so: “I want to understand the health concern and the next step, without focusing on appearance.”
Support nourishment without dieting
Aim for regular meals and snacks that you can tolerate. An everyday meal might combine a grain or starchy food, a protein food and vegetables, with fruit and calcium-rich foods elsewhere in the day. You do not need to eliminate carbohydrates or skip meals to compensate for a higher reading.
Practical options include keeping easy food available, asking someone to help with shopping, or preparing a simple meal when you have more energy. Well-cooked eggs on wholegrain toast, yoghurt with fruit, or a freshly cooked bean-and-vegetable dish can be more realistic than an elaborate menu.
If eating enough is difficult, or you have been advised to adjust your intake, ask for an Accredited Practising Dietitian. Avoid crash diets, fasting for weight loss and weight-loss supplements. If you take a weight-management medicine, arrange a prompt medication review with your prescriber.
Australian healthy-pregnancy guidance advises against restrictive dieting during pregnancy. Our pregnancy nutrition guide explains food choices and supplements without a fixed calorie prescription.
Choose movement that feels manageable
For an uncomplicated pregnancy, regular physical activity can support physical and mental wellbeing. Walking, swimming and appropriately adapted strengthening exercise are possible options. If you are starting from very little activity, build up gradually.
Australian guidance recommends 150–300 minutes of moderate activity a week for healthy pregnancies, spread across the week. You should be able to hold a conversation at moderate intensity. Get individual advice about restrictions if you have complications, and stop an activity that causes pain or makes you unwell. Movement should support you, rather than be punishment for eating.
See the Australian Government’s pregnancy activity guidance and our pregnancy exercise article.
What if you are losing weight?
Nausea can affect intake, especially early on, but ongoing weight loss needs a conversation with your clinician at any starting size. Do not assume that having a higher pre-pregnancy weight makes significant vomiting or poor intake harmless.
Seek medical help promptly if you cannot keep fluids down, have very dark or little urine, feel faint, or are losing weight with continuing vomiting. Treatment and nutrition support are available. Read when to seek help for pregnancy sickness.
When a sudden change needs urgent care
Contact your maternity unit or seek urgent medical assessment if you develop a severe or persistent headache, changes in vision, pain high in your abdomen, sudden swelling or rapid weight gain, or feel very unwell. These can be signs of pre-eclampsia. Do not wait for the next routine appointment. Pre-eclampsia can also occur without noticeable symptoms, which is why blood-pressure checks matter.
Healthdirect explains pre-eclampsia warning signs. Call 000 for a seizure, collapse or severe breathing difficulty.
If weighing brings up difficult feelings
You deserve respectful care at every body size. Let your team know about past or current eating difficulties, distress about body changes, or a wish not to hear the number during a necessary weight check. Ask how they can monitor your health while making appointments less stressful.
A useful plan should leave you knowing what to eat, when to seek help and who to contact. It should not leave you feeling that you have to manage the pregnancy alone.
This is general information for an Australian audience. Your pregnancy care team can help interpret weight changes in your individual circumstances.
