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Pregnancy health centre

33 weeks pregnant

WebMD Medical Reference
Medically Reviewed by Dr Rob Hicks


How is your baby growing at 33 weeks?

Your baby continues to grow and is about 44cm long and weighs around 2kg (4.4lb). Although your baby's bones had been flexible, they should now become denser and form into hard bone. The exception is the bones in your baby's skull, which remain separated and soft so the baby can travel down the birth canal during childbirth. Your baby's brain and nervous system will now be fully developed, ready for the outside world.

Life inside the womb is getting cramped, with arms and legs curling up, so while you still should feel movements, don't expect them to be as active as last month. Most babies will have turned into a head-down position by this week, in preparation for birth, but not all – some babies will continue to change positions.

Your baby may be sleeping more often, much like a newborn baby.

How are you changing in week 33?

You are still putting on weight, but remember you need to keep eating a healthy nutritious diet with good sources of vitamins and minerals including calcium. Your baby will be drawing on calcium from you to make and harden bone, so your own bones may suffer if you don't include enough calcium in your diet. If you are worried about the amount of weight you are putting on, talk to your midwife or doctor, who can provide you with the appropriate advice and reassurance for your pregnancy – never miss out on meals because you think you weigh too much.

About half of first-time mums-to-be will have a sensation of feeling especially heavy in the pelvic area. If you experience this sensation, it is a sign that your baby has turned into a head-down position and is putting pressure on your cervix. In women you have already had babies, this normally occurs about 1 week before birth.

The increase of the hormone progesterone during pregnancy causes the blood vessels to relax. The pressure and weight of the growing baby and womb also reduces the blood flow in your lower body, which can cause veins in your legs to swell, become sore and turn blue – these are known as varicose veins. They are similar to haemorrhoids, or piles, that sometimes form in the rectum, vagina or vulva during pregnancy. The more often you have a baby, the greater your chances of developing varicose veins. The condition is also more likely if there's a history of varicose veins in your family. If the affected veins become red, tender and hard, you may have blood clots, or thrombophlebitis. Seek medical advice straight away if these symptoms occur.

Bleeding from the anus can be a sign of haemorrhoids. They should disappear after the baby is born. However, sometimes anal bleeding is due to a tear (fissure) in the anus, though these are more common after pregnancy.

If you haven't experienced leaking of colostrum already, you may start to do so now. You'll notice a yellowish liquid – your baby's first feed – leaking from your nipples. Slipping breast pads into your bra will be helpful in absorbing the moisture. Some women won't have any leaks at all before pregnancy.

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