You’ve always had a naturally slender build and a fast metabolism, so you’ve never come across issues with gaining too much weight, and it’s not something that’s ever particularly crossed your mind.

However, when you got pregnant, things started to change. In your first trimester, you gained five pounds and felt a little fuller around your face. In your second, the buttons on your maternity jeans started to pop off, and your friends started to comment on how ‘healthy’ you looked.

Although you’re not opposed to gaining a little weight during your pregnancy, you’re starting to wonder - Is the rate at which I’m putting on weight healthy? How much more weight will I gain until I give birth?

Rest assured that weight gain is a significant part of a healthy pregnancy, usually happening during the second and third trimesters. However, it’s important to monitor your weight gain during this time, and understand whether or not it is healthy.

So, let’s dive into understanding some questions about weight gain during pregnancy. Starting with whether you can expect to gain more weight during this time.

How much more will I weigh during pregnancy?

Generally, by the end of a pregnancy, a person will usually weigh 10kg to 12.5kg (22 to 27.6lb) more than they did before they became pregnant. They will also gain most of their pregnancy weight during the second half of the pregnancy.

Here are some averages as to what you can expect regarding weight during pregnancy:

At 40 weeks, a baby will typically weigh around 3.5kg (7.6lb).
The placenta will weigh around 0.7kg (1.5lb). The placenta is key to keeping your baby nourished.

The amniotic fluid will weigh around 0.9kg (2lb). The amniotic fluid is what cushions and supports your baby while it grows.

However, it’s important to note that every person and every pregnancy is different. Therefore, you can’t base predictions for your own weight gain on someone else’s. The best way to calculate a more personal guideline is to look at a pregnancy weight gain estimator. Based on your own height and pre-pregnancy weight, this will help you estimate how much weight you might gain during your own pregnancy journey.

Now that we’ve talked about general weight expectations during your pregnancy, let’s outline what you should do if you have a high BMI and are pregnant.

What should I do if I have a high BMI and I’m pregnant?

If you have a BMI of 30 or more before you conceive, it’s important you talk to your midwife or doctor. This is because having a BMI of 25 or more at the start of pregnancy can increase the risk of complications occurring during it. For example:

Gestational diabetes.

Thrombosis.

High blood pressure.

Pre-eclampsia.

Induced labour.

A caesarean.

Complications with pain relief in labour.

A premature labour and birth.

Your midwife or doctor may in turn refer you to a specialist health professional or give you some personalised advice on how to best control your weight gain. However, it’s equally important to refrain from low-calorie or crash diets, as these can negatively affect your baby.

Why am I gaining weight during pregnancy?