You are 21 weeks and 5 days

Bellies come in all shapes and sizes, and your doctor will keep track of how your baby is growing.

128 days until your due date

If you feel big for halfway, it doesn't necessarily mean a big baby. Not all your weight is in your belly or from your baby; you may have gained weight elsewhere that doesn't affect the baby's size. Women carrying twins or triplets naturally show earlier and have much bigger bellies.

Your belly size is a good guide to your baby's growth, so your doctor will measure it from your pubic bone to the top of your uterus (the fundus). In centimeters, this should roughly match the number of weeks you're pregnant, within 2 cm (¾ in); at 28 weeks, for example, it should be 26–30 cm (10¼–11¾ in). This "symphysis fundal height" (SFH) is written in your notes.

If your belly is much bigger or smaller than expected for your dates, you'll probably be sent for an ultrasound, which measures your baby's size much more accurately.

Remember, what feels huge to you and what your doctor considers too big can be very different. You're used to your body being a certain size, so you feel much bigger, even though to doctors you're a normal, healthy size, especially if you've always been slim.

Explainer

Don't compare bumps

It's nice to spend time with women at the same stage, but try not to compare. Your belly may be bigger than your friend's, yet you may end up with a smaller baby.

Ask a Nutritionist

I've been told to rest. Will I gain too much weight?

It's important to follow this advice, even though it's frustrating. Ask your doctor whether gentle walking or swimming is allowed, which will keep you fit and burn some calories.

If you eat a healthy diet with plenty of fresh fruit and vegetables, complex carbohydrates, and lean protein, you shouldn't gain too much weight.

Never diet or go hungry because you're less active. Regular meals and snacks matter; if you're hungry, your body needs fuel.

If you've been prescribed full bed rest, even light exercise will be ruled out, so check at the start what is and isn't allowed. You'll probably gain some weight if you're inactive, but the aim of bed rest is a healthy, full-term baby, which is worth a few extra pounds.

This is general information based on NHS guidance, not medical advice, and every pregnancy is different. Talk to your midwife or GP about anything that worries you. If your baby's movements slow down or change, or you have bleeding, severe pain or leaking fluid, call your maternity unit straight away. In an emergency, call 999.

Don't compare bumps

I've been told to rest. Will I gain too much weight?

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