Normal Weight Gain During Pregnancy

From cheerful and glowing to nauseous and exhausted, every woman's experience of pregnancy is different. But there is one absolute certainty: you will gain weight during pregnancy.

The good news is that for once in your life, those few extra kilos aren't cause for concern. In fact, they're a healthy and necessary part of the process. But what exactly is normal weight gain during pregnancy? How much is too much weight or too little?

If you were underweight to start with, you might need to gain a few more kilos than the average mum-to-be. Women who don't put on enough weight during pregnancy are at higher risk of premature birth, having babies with low birth weight and other complications.

But if you were heavier before your pregnancy, you'll probably need to keep your weight gain in check. Being overweight or adding too many kilos during pregnancy can lead to complications such as high blood pressure, gestational diabetes, birth defects or having a big baby.

Don't worry if you're pregnant or trying to conceive and you aren't at your optimal weight - it's not too late to start following a healthy eating and exercise plan like the 12WBT to get back on track.

How Much Weight Should You Gain?

The ideal number of kilos you should gain during pregnancy is determined by your pre-pregnancy body mass index (BMI), which measures your weight in relation to your height. Here's how to calculate your BMI:

Your pre-pregnancy weight: ________ kg
Your height: ____________ m (eg 165cm is 1.65m)

BMI = weight/(height x height) = _____ kg/m²

Let's say you weighed 62kg before you got pregnant and you're 1.65m tall:

BMI = 62/(1.65x1.65) = 62/2.72 = 22.8

According to the National Health and Medical Research Council, if your BMI was:

  • Less than 18.5 (underweight), you should gain between 12½kg and 18kg
  • 18.5 to 24.9 (normal weight), you should gain between 11½kg and 16kg
  • 25 to 29.9 (overweight), you should gain between 7kg and 11½kg
  • 30 or more (obese), you should gain between 5kg and 9kg

If you're carrying twins or triplets, you'll need to gain more weight during your pregnancy. Talk to your doctor to find out exactly how much you should put on, depending on your circumstances.

Where Does the Weight Go?

If your baby weighs only a few kilos when born it can leave you wondering where all those other kilos go. Here are some average figures:

Baby: 3.0 to 3.6kg
Placenta: 0.7kg
Amniotic fluid: 1kg
Larger uterus: 1kg
Increased blood volume: 1.4 to 1.8kg
Extra fluid: 1.4 to 1.8kg
Bigger breasts: 1kg
Fat stores: 2.7 to 3.6kg

First Trimester Gains

During the first three months of pregnancy, women should gain only 1-2kg, regardless of their pre-pregnancy BMIs. The harsh truth is that you don't really need any extra calories in the first trimester, so ‘eating for two’ is nothing but a myth.

If you experience morning sickness and can't seem to keep anything down, you might not gain much weight - you might even lose some. This generally isn't anything to worry, you can make up for it in the second and third trimesters.

On the other hand, snacking regularly during pregnancy might be the only remedy if you suffer from constant nausea. But this practice could lead to above-average weight gain. Try not to use morning sickness (or food cravings) as a reason to overindulge in unhealthy processed foods.

If carbohydrates like biscuits and bread are the only things you can stomach, reach for the wholegrain variety, which will provide more nutrients and longer-lasting energy. And if you crave sugar, stock your kitchen with fruit rather than chocolate and ice-cream. That said, don't be too hard on yourself - indulge your cravings in moderation.

Do your best to follow the weight-gain guidelines, but don't panic if you're a little off. If you've gained a lot less or more than you should, talk to your doctor.

Second and Third Trimester Gains

From the beginning of your second trimester until you give birth, follow these guidelines. If your pre-pregnancy BMI was:

  • Less than 18.5, you should gain ½kg/week
  • 18.5 to 24.9, you should gain 400g/week
  • 25 or more, you should gain less than 300g/week

You can finally eat (a little) more! In order to keep your weight gain on track, you'll need to increase your daily energy intake by approximately 200-260 calories. Before you order that large pizza, though, keep in mind that this number of calories is equivalent to only one cup of skim milk and a large banana, or two slices of wholemeal toast with one tablespoon of peanut butter.

By the second trimester, the nausea and morning sickness should start to ease off. On the one hand, that means you'll be able to stomach more than just dry biscuits - but on the other, no more excuses to eat junk!

If you haven't already, now's the time to put your healthy eating plan into place.

Healthy Eating Tips For Pregnancy

You'll probably find that controlling your food intake is a lot harder during pregnancy as your baby is constantly ordering ‘womb service’ - and now is definitely not the time to diet or try to lose weight. Instead, try to make healthy food choices as often as possible.

Eat regularly throughout the day to control your hunger and keep your energy levels high. In addition to your three regular meals, you should have two or three snacks. Examples of healthy snacks include fruit, cheese and crackers, yoghurt, nuts and seeds.

If you're used to restricting some food groups when you're not pregnant (such as carbohydrates), it's time to include them in your diet again to ensure your baby is getting all the nutrients it needs. In particular, the requirements for folate, iron and iodine increase during pregnancy. You can choose foods that are rich in these nutrients or take a supplement - but be sure to talk to your doctor before you do.

The National Health and Medical Research Council's Dietary Guidelines for Australian Adults recommend that pregnant women eat the following amounts of each food group every day. The portions in brackets are examples of one serve.

  • Cereals, breads, rice, pasta and noodles: 8½ serves (eg. 1 slice bread, ½ cup cooked rice, pasta or noodles)
  • Fruit: 2 serves (eg. 1 medium apple, 2 small plums, 4 dried apricot halves, ½ cup fruit juice,)
  • Vegetables and legumes: 5-6 serves (eg. ½ cup cooked spinach, 1 cup raw leafy greens, ½ medium potato)
  • Lean meat, fish, poultry, eggs, nuts and legumes: 3½ serves (eg. 90-100g raw weight lean meat or chicken, 2 small eggs)
  • Milk, yoghurt and cheese: 2½ serves (eg. 1 cup low-fat milk, 2 slices or 4 x 3 x 2cm piece hard cheese)
  • Drink plenty of water

Staying Active During Pregnancy

As long as your pregnancy is progressing normally, regular exercise can help control your weight. It also provides a host of other benefits, including improved sleep, easier labour and a quicker return to a healthy weight after birth.

Before you start a new exercise program or continue the one you were following before pregnancy, consult your doctor to make sure it's safe for you and your baby.

Once you get the green light, aim for at least 30 minutes of moderate-intensity exercise on most days - you should be able to hold a conversation without being short of breath. Safe activities include swimming, walking, cycling, yoga, pilates, dancing, water aerobics and pregnancy exercise classes.

Even running and strength training can be perfectly safe in moderation if you engaged in these activities before pregnancy. But no matter which exercise you choose, listen to your body and don't let your body temperature get too high or exercise to the point of exhaustion.

Keep in mind that the goal of exercise during pregnancy is to stay fit and healthy - not to lose weight.

Think of every bite you take as a building block for your baby's development - with whole foods being far superior to processed ones. With that in mind, opt for an apple over apple crumble whenever you can.

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