How much weight should you gain during pregnancy?

It’s probably safe to assume that pregnancy is going to be one of the biggest changes your body will ever go through. You might experience a lot of weird symptoms and/or discomfort. And then there’s the weight you put on.

Pregnancy weight gain can be a source of anxiety for some women, while for others it’s a beautiful reminder of the little person they’re carrying around in their belly. 

The first thing to come to terms with is that most women need to put on extra weight to safely grow a baby. But what’s considered ‘healthy’ pregnancy weight gain?

A starting point: Average weight gain during pregnancy

Most medically reviewed sources suggest that the typical amount of weight pregnant women gain is around 25 to 35 pounds (11-16kg). But don’t take that as gospel. SO many factors play into this whole thing. The ideal ‘healthy weight gain in pregnancy’ differs from woman to woman (and even between your own pregnancies). 

Let’s have a look at some of the factors that can affect weight gain during pregnancy.

Pre-pregnancy weight

Mayo Clinic points out that the recommended weight gain during pregnancy (as we mentioned above) is based on an average pre-pregnancy weight. A ‘normal weight’ is when your BMI* is between 18.5 and 24.9. 

*WTF is BMI? It stands for Body Mass Index, and you can calculate yours online – you just need to know your height and weight. 

Women who begin pregnancy underweight (BMI under 18.5) may be advised to gain a little more – 28 to 40 lbs (about 13 to 18 kg).

On the other hand, if you start out overweight before conceiving, you may be advised to gain closer to 15 to 25 lbs (about 7 to 11 kg). 

Your doctor can chat with you about the unique recommended amount of weight YOU should gain, taking into account any medical conditions or if you’re carrying twins (which obviously changes things). 

Eating habits

How and what you eat can influence weight gain during pregnancy. For example, if you get a bit loose and binge on all the junk food, you may gain more weight than if you prioritize a healthy diet packed with nutritious pregnancy foods. Goes without saying, really.

Activity levels

Women who are highly active may not gain as much weight as women who don’t exercise much during pregnancy, or spend a lot of their day sitting down. More physical activity might mean you need to pack extra calories into your diet and could alter your ideal gestational weight gain.

Pregnancy symptoms

Morning sickness could impact your weight gain, while cravings or aversions may also change how and what you eat.

Fluid retention

This can become common in the later stages of pregnancy and is known as edema. It can be uncomfortable AF and make you gain extra unexpected weight.

When do you start gaining weight in pregnancy?

While you may put on some weight in your first trimester, don’t be too worried if you’re not a whole lot heavier, or if you even end up losing a few pounds. Spewing your guts up every day for 13 weeks can really have that effect. 

The second and third trimester is when things really ramp up with pregnancy weight gain. 

Recommended weight gain by trimester

Trimester One

The Royal Women’s Hospital says that all women tend to put on about ½ to 2 kilos (1.1 to 4.4 pounds) in the first three months of pregnancy. But this should be taken with a grain of salt. Some women may lose weight during the first trimester due to severe morning sickness. 

Others may be tempted to overeat during the early months due to early pregnancy hunger. But you’re not actually ‘eating for two’ and don’t technically need extra nutrients in the first trimester. (Sorry.)

If you’re concerned about excessive weight gain or are worried that you’re not putting on enough pounds during pregnancy, check in with your obstetrician for advice. 

Trimester Two

Around the fourth month of pregnancy, hopefully morning sickness subsides and you enjoy a bit of an energy boost. 

Excitingly, you may start to notice your belly growing (time to invest in your maternity wardrobe!) But on that note: bump size isn’t a good indicator of weight gain. You may think you look HUGE, but be right in range with your pregnancy weight. Or you may not see much sign of a bump at all throughout your pregnancy.

Women carry their baby bumps differently, so don’t compare yours to someone else’s.

In your second trimester, you’re expected to gain around 1 pound (0.5kg) per week for women of normal pre-pregnancy weight.

Trimester Three

Weight gain in the third trimester is similar to your second. You’ll put on around one pound (0.5kg) per week up until you deliver. You may notice some week by week fluctuations in weight, and that’s generally normal.

Remember – every woman is different and you should confirm any healthy weight targets with your healthcare provider.

Where the pregnancy weight goes (is it ALL baby?)

So you may be thinking, “35 pounds?! I’m not giving birth to a 35-pound baby am I?”. Thankfully, no (we really, really hope for your vagina’s sake). 

Here’s roughly how it’s distributed (Sourced from Healthline):

  • Baby – At birth, the average baby weighs around 7.5 pounds (3.4 kg).
  • Body fluid – During pregnancy you’ll produce about 4 pounds (1.8kg) of body fluid.
  • Placenta – Ever lay awake at night wondering, ‘How much does a placenta weigh?’ Haven’t we all. About 1.5 pounds (0.7kg), it turns out!
  • BOOBS – You’ll probably notice the ladies growing as they make way for a very clever feeding system. They may add about 2 pounds (0.9kg) to your pregnancy weight (and they’ll look FAB).
  • Blood – Increased blood volume (which DOUBLES during pregnancy) contributes an extra 4 pounds (1.8kg) to your body. Wild.
  • Fat and protein – This is stored in the body to assist delivery and breastfeeding, and usually adds around 7 pounds (3.1kg).
  • Amniotic fluid – Your baby is bobbing around in approximately 2 pounds (0.9kg) of fluid in your uterus.

Pregnancy weight concerns

Gaining too much weight

One study revealed that 47% of women gain more than the recommended amount of pregnancy weight. While you’re still likely to have a healthy baby if you gain a lot of weight, this can increase the risk of gestational diabetes and macrosomia (the baby being born well above average birth age, which can lead to delivery complications).

If you’re packing on the pounds faster than you think you should be, get advice from your doctor about managing your weight in pregnancy.

Gaining too little weight

Around 20% of women (in the same study mentioned above) gained less than the recommended weight during pregnancy. While this also doesn’t guarantee pregnancy complications or birth defects, it can add risk of preterm birth and your baby being born below normal birth weight.

If you’re struggling to eat enough to put weight on, have a talk with your maternal care team. It may be a matter of prioritizing nutrient-rich foods in your pregnancy diet (topping up with a prenatal vitamin may help!), or taking medication to keep morning sickness at bay.

What happens to pregnancy weight after birth?

There’s a lot of pressure on moms to return to their pre-pregnancy weight after giving birth. But it’s all a load of BS to be honest.

Rather than depriving yourself of food (because you need that good stuff, particularly postpartum) or overexercising, honor your brilliant body for what it’s just done – grown a person!

The good news is you’ll probably feel a bit lighter instantly after delivering your baby and placenta – that alone relieves you of around 9 pounds (4kg)! But it may take a few months to lose all the pregnancy weight. Some women find it takes years. Your body may never really go back to ‘normal’ – and that’s totally fine. It might have a ‘new normal’ now – and hear this: It. Is. Stunning.

One final word

A healthy pregnancy isn’t all about weight management. You can still grow a healthy, beautiful bub if you’re outside of the recommended weight gain range. Every body is different and every pregnancy is different.

As long as you’re taking care of yourself and attending your regular pregnancy screenings, don’t get hung up on weight gain and just enjoy the process of creating life.

You’ll find more helpful tips, high fives, and encouraging pats on the bum on Mumli, your pocket-sized personal assistant for all things motherhood – coming to your home screen soon. Join the waitlist now.

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