Week 33 of pregnancy places you firmly in the third trimester, with your due date now feeling reassuringly close. This is a week of steady growth and preparation, as your baby continues to gain weight and your body begins its own quiet work of getting ready for birth. Many parents notice pregnancy feels more physical now, and it is entirely normal to be thinking ahead to labour, your birth plan, and those final appointments.
Having moved on from week 32, you are now well into the home stretch. Understanding what is happening this week, both for your baby and for you, can help you feel more confident and prepared as you approach week 34 and beyond.
Your baby at week 33
By week 33, your baby is growing quickly and running out of room to move as freely as before. At this stage a baby typically measures around 43 to 44 centimetres from head to heel and weighs approximately 1.9 to 2 kilograms, though there is a wide and completely normal range from one baby to the next.
Much of this week's development is about refinement rather than dramatic change. Your baby is laying down fat beneath the skin, which helps smooth out their appearance and will support temperature regulation after birth. The bones are continuing to harden, with the notable exception of the skull, which stays soft and slightly flexible to help with the journey through the birth canal.
Your baby's brain and nervous system are developing rapidly, and their sleep patterns are becoming more established, with periods of rest and activity you may recognise through the day. Many babies have settled into a head-down position by now, although some have not, and there is still time for this to change.
Your body at week 33
As your baby grows, you may feel the effects more keenly. Common and generally normal symptoms around week 33 include:
- Shortness of breath, as your growing uterus presses upwards towards your lungs and diaphragm.
- Backache and pelvic discomfort, as your posture shifts and pregnancy hormones soften the ligaments.
- Swelling in the feet, ankles and hands, particularly later in the day or in warm weather.
- Braxton Hicks contractions, which are irregular, usually painless tightenings as your uterus practises for labour.
- Trouble sleeping, heartburn, and more frequent trips to the loo as your bladder is under pressure.
From around 28 weeks, the NHS advises resting and sleeping on your side rather than your back, as this is thought to be safer for your baby in the third trimester. If any symptom feels sudden or severe, trust your instincts and seek advice rather than waiting.
What to keep in mind this week
It is important to be aware of the signs that need prompt attention. Contact your midwife or maternity unit straight away if you experience a sudden or noticeable change in your baby's movements, severe or persistent headache, vision disturbances, sudden swelling of the face, hands or feet, or any vaginal bleeding. These can be signs that need checking, and maternity teams would always rather hear from you.
Monitoring your baby's movements remains one of the most valuable things you can do this week. There is no set number of movements to expect, but you should get to know your baby's individual pattern. If that pattern changes or slows, do not wait until the next day, and never rely on home dopplers for reassurance.
This is also a sensible time to think practically about the weeks ahead, from finalising your birth plan and hospital bag to arranging any support at home. Keeping track of where you are can help, and our pregnancy journey planner offers a personalised timeline of your milestones and appointments.
Scans, tests and appointments
By week 33, the major routine NHS screening milestones are behind you. The dating and combined screening happen in the first trimester, the anomaly scan takes place between around 18 and 21 weeks, and the glucose tolerance test, where offered, is typically carried out between 24 and 28 weeks.
Some appointments remain relevant now. The whooping cough vaccine is offered from around 16 weeks and can still be given up to around 32 weeks, and the RSV vaccine is offered from 28 weeks of pregnancy to help protect your newborn. Your midwife may also begin discussing group B Streptococcus in the later part of the third trimester, so this can be a good moment to raise any questions.
Routine NHS care does not usually include an ultrasound scan in the third trimester unless there is a specific clinical reason. If you would value extra reassurance about your baby's growth, position and wellbeing between routine appointments, a private wellbeing scan can offer a detailed check at this stage. For continuity of care and time to talk things through, our private midwife appointments give you dedicated, personalised support as you prepare for birth.
Looking ahead
Week 33 is a week of quiet progress, with your baby steadily gaining strength and your body preparing for what lies ahead. Rest where you can, stay attentive to your baby's movements, and use these weeks to get organised for the arrival to come. Next comes week 34, another step closer to meeting your baby.
This article is for general information only and is not a substitute for professional medical advice. Always speak to your midwife, GP or obstetrician about your own pregnancy.
